Draft 2.2
rev. 16-Sep-2014
T.H. Prettyman
Planetary Science Institute
Albuquerque, NM
USA
S. Joy and J. Mafi
Dawn Science Center
University of California, Los Angeles
Los Angeles, CA 90095-1567
2007 Dawn/GRaND Gamma Ray and Neutron Detector
GRaND STANDARD DATA PRODUCTS
ARCHIVE VOLUMES
SOFTWARE INTERFACE SPECIFICATION
(GRaND EDR & RDR Archive Volumes SIS)
Version 2.2
rev. 16-Sep-2014
Approved:
Thomas H. Prettyman      Date
Experiment Team Lead
Steven P. Joy
Dawn Science Center Manager      Date
Christopher T. Russell
Dawn Principal Investigator      Date
Michael F. A'Hearn      Date
PDS Lead Node (SBN) Manager
1. INTRODUCTION ...........................................................3 1.1. Distribution List.....................................................4 1.2. Document Change Log ..................................................4 1.3. TBD Items ............................................................5 1.4. Acronyms and Abbreviations ...........................................5 1.5. Glossary .............................................................6 1.6. Dawn Mission Overview ................................................7 1.7. Content Overview .....................................................9 1.8. Scope ................................................................9 1.9. Relationship to Other Dawn Archives ..................................9 1.10. Applicable Documents ................................................9 1.11. Audience ............................................................11 2. Gamma Ray and Neutron Detector Instrument Description ..................12 2.1. Science Objectives ...................................................12 2.2. Measurement Principle ................................................12 2.3. Detectors ............................................................13 2.4. Electronics ..........................................................17 2.5. Measured Parameters ..................................................17 2.6. Operational Modes ....................................................19 2.7. Operational Considerations ...........................................20 2.8. Ground Calibration ...................................................20 2.9. Inflight Calibration .................................................20 3. Data Set Overview ......................................................21 3.1 Data Sets .............................................................21 3.2 Level-0 Data Flow .....................................................23 3.3 Data Processing and Production Pipeline ...............................24 3.4 Data Flow .............................................................26 3.5 Data Validation .......................................................28 3.6 Archive Schedule ......................................................28 4. Archive Volumes ........................................................29 4.1 Volume Creation .......................................................29 4.2 Volume Format .........................................................29 4.3 Volume Labeling and Identification ....................................29 4.4 PDS Peer Review .......................................................29 5. Archive Volume Contents ................................................31 5.1 Root Directory Contents ...............................................31 5.2 INDEX Directory Contents ..............................................31 5.3 CATALOG Directory Contents.............................................32 5.4 CALIB Directory Contents ..............................................32 5.5 DATA (Standard Products) Directory Contents and Naming Conventions ....32 6. Archive Volume Contents ................................................35 6.1 EDR Data Product Format Description ...................................35 6.2 Example state (.STA) file .............................................38 6.3 RDR Data Product Format Description ...................................39 6.4 Data Product Design ...................................................40 A. Appendix A: Sample PDS Labels ..........................................45 A.1 EDR Data Product Label ................................................45 A.2 EDR Data Product Structure File .......................................46 A.3 RDR Data Product Label ................................................84 A.4 RDR Data Product Structure File .......................................86 A.5 Index Table Label .....................................................103 A.6 Example Document Label ................................................108 B. Appendix B. Support Staff and Cognizant Persons ........................111
This document describes the contents and types of archive volumes belonging to all of the Dawn GRaND NASA level 1 (CODMAC levels 2 and 3) data sets.
The archive contains experimental data records (EDR) acquired by GRaND during Earth-Mars Cruise, Mars Gravity Assist, Mars-Vesta Cruise, and Vesta encounter from October 10, 2007 to August 9, 2012. In Feburary of 2009, Dawn flew by Mars, bringing GRaND close enough to the surface to measure neutron and gamma ray leakage spectra. The data from Mars Gravity Assist (MGA) were reduced and analyzed for calibration purposes. An analysis of Mars fly data is given by Prettyman et al. (2011). In 2011 and 2012, Dawn acquired science data at Vesta. Studies with GRaND data strengthened the link between Vesta and the HEDs and revealed traces of exogenic, H-rich materials in Vesta’s regolith (Prettyman et al., 2012, 2013; Lawrence et al., 2013; Peplowski et al., 2013; Yamashita et al., 2013). Reduced Data Records (RDR) for MGA and Vesta encounter are included in the archive.
The EDR (Level1A) and RDR (Level1B) provide a time ordered collection of gamma ray and neutron counting data including histograms and pulse height spectra. In addition to counting data, EDR include state-of-health data (instrument settings, temperature and voltage readings) needed for scientific analysis of the neutron and gamma ray data. The RDR include calibrated pulse height spectra, counting rates, propagated uncertainties, and ancillary pointing and ephemeris data needed for mapping. In developing the archive, ASCII tables were used, where possible, to maximize portability and ease of use. As a result, there are only two binary type data files (Level1A) in the archive. In addition, IDL routines are provided to read the Level1A data. The Level1B data sets consist entirely of human-readable, ASCII tables.
This document provides an overview of the archive, and details on the structure and format of the data (Section 6). The detailed processing steps are described in the Data Processing Document that accompanies this archive (in PDF and HTML formats as GRaND_Data_Proc.pdf and GRaND_Data_Proc.htm, respectively). Much of the information in the Data Processing Document is repeated in the GRaND instrument mansucript (Prettyman et al., 2011), which also includes some examples of how the data can be used (e.g., the analysis of MGA data). A complete list of data acquired during flight up to Vesta approach can be found in the Data Processing Document and instrument manuscript. Additional data processing documents are provided for Vesta encounter, which present the state-of-the-art for Level 1B processing: GRD_L1B_EPG_v1.pdf (Prettyman 2014a); and GRD_L1B_BGO_Data_Processing_v3.pdf (Yamasita and Prettyman 2014).
The information provided here is supplemented by formal Activity Reports, which are included in the archive. The reports describe each of the major activities, including goals, issues, and outcomes. During Vesta encounter, status reports were generated automatically by the data processing pipeline. These included instrument state information, and charts with state-of-health and histograms, which served as a guide to GRaND’s state-of-health and measurement conditions. Similar status reports accompany the PDS data, providing an overview of data within each top-level directory.
------------------------------------------------------------------------- Table 1: Distribution List ------------------------------------------------------------------------- Name Email ------------------------------------------------------------------------- T. Prettyman prettyman@psi.edu N. Yamashita yamashita@psi.edu M. A’Hearn ma@astro.umd.edu C. Neese neese@psi.edu S. Joy sjoy@igpp.ucla.edu J. Mafi jmafi@igpp.ucla.edu C. Raymond carol.raymond@jpl.nasa.gov C. Russell ctrussell@igpp.ucla.edu -------------------------------------------------------------------------
------------------------------------------------------------------------- Table 2: Document Change History ------------------------------------------------------------------------- Change Date Affected Portions ------------------------------------------------------------------------- Boilerplate Draft by S. Joy 18 Jun 2009 All Additions by J. Mafi 15 Oct 2009 All Revisions by T. Prettyman 23 Dec 2009 All Revisions by T. Prettyman to 5 Jan 2010 Revised section 6 include description of EDR and RDR data files Updates to mission description 26 Jan 2010 1.2, 1.3, 1.6, 3.1, 3.3, and various tables; added 3.6, 4.3, 5.1-5.6, 6.1, higher level product 6.3 information Corrections (typo corrections, 7 May 2010 1.8, 1.10, 2.2, 2.4, 2.5, and additional text) 3.3, 3.5, 3.6, 5.6, 6, 6.4 requested in peer review Table of content format 19 Aug 2010 Table of contents Revisions and corrections by 29 Sep 2010 All T. Prettyman to address review comments Updated label and FMT 13 Jun 2011 6.4.6-6.4.7, A.1-A.4 file samples to latest versions Revisions and corrections by 2 Feb 2012 5 and 6 T. Prettyman to address reviewer comments. Corrected numbering of 11 Jul 2013 6.5; 5.5.1; 1.10 subsections in Section 6.5; Removed reference to datainfo.txt in Section 5.5.1; Updated applicable documents Addition of documentation of 16-Sep-2014 1, 1.6, 1.10, 2.2, 3.1, Vesta reduced data records by 3.1.1, 3.3.2, 3.3.3, 6.3, B T. Prettyman -------------------------------------------------------------------------
Items that are currently TBD or not finalized, but need to be defined prior to release:
------------------------------------------------------------------------- Table 3: TBD Items ------------------------------------------------------------------------- Item Section Pages ------------------------------------------------------------------------- Relationship to other Dawn 1.9 archives -------------------------------------------------------------------------
------------------------------------------------------------------------- Table 4: Acronyms, Initialisms,and Abbreviations ------------------------------------------------------------------------- Acronym Definition ------------------------------------------------------------------------- ASCII American Standard Code for Information Interchange CDROM Compact Disc, Read Only Memory CODMAC Committee on Data Management and Computation DHSU Data Handling and Support Unit DSC Dawn Science Center DSDb Dawn Science Database DVD Digital Versatile Disc EGSE Engineering Ground Support Equipment FC Framing Camera(s) FLTOPS JPL Multi-mission Flight Operations Gb Gigabit(s) GB Gigabyte(s) GRaND Gamma Ray and Neutron Detector GSE Gravity Science Experiment HAMO High Altitude Mapping Orbit INAF Istituto Nazionale AstroFisica ISO International Standards Organization JPL Jet Propulsion Laboratory LAMO Low Altitude Mapping Orbit NSSDC National Space Science Data Center ME Main Electronics OM Optics Module PDB Project Database PDS Planetary Data System PEM Proximity Electronics Module RMOC Remote Mission Operations Center SAMO Survey Altitude Mapping Orbit SBN Small Bodies Node S/C Spacecraft ST Science Team SIS Software Interface Specification TM TeleMetry TBD To Be Determined UCLA University of California, Los Angeles VIR Visual and Infrared Mapping Spectrometer -------------------------------------------------------------------------
Archive - An archive consists of one or more Data Sets along with all the documentation and ancillary information needed to understand and use the data. An archive is a logical construct independent of the medium on which it is stored. Archive Volume - A collection of files formatted according to the PDS Archive Volume standards. This collection may be electronic or stored on a PDS approved physical media such as DVD or CDROM. Archive Volume Set - A collection of one or more Archive Volumes used to store a single Data Set or collection of related Data Sets. Catalog Information - High-level descriptive information about a Data Set (e.g., mission description, spacecraft description, instrument description), expressed in Object Description Language (ODL), which is suitable for loading into a PDS catalog. Data Product - A labeled grouping of data resulting from a scientific observation, usually stored in one file. A product label identifies, describes, and defines the structure of the data. An example of a Data Product is a planetary image, a spectral table, or a time series table. Data Set - A Data Set is a collection of Data Products from a single instrument that have a common data processing level, together with supporting documentation and ancillary files. Standard Data Product - A Data Product generated in a predefined way using well- understood procedures, processed in "pipeline" fashion. Data Products that are generated in a nonstandard way are sometimes called special Data Products.
The Dawn mission will study two main belt asteroids, Vesta and Ceres. Both bodies are believed to have accreted early in the history of the solar system. They have been selected because while they can speak to conditions and processes early in the formation of the solar system, they developed into two characteristically different bodies. Vesta is a dry differentiated body with a surface showing signs of resurfacing. Ceres has a primitive surface containing water-bearing minerals and may possess a weak atmosphere. By studying both these bodies, the Dawn mission hopes to compare the different evolutionary path each took as well as characterize conditions of the early solar system.
To carry out its scientific mission, the Dawn spacecraft carries three science instruments. These instruments are: a visible camera (FC), a visible and infrared mapping spectrometer (VIR), and a gamma ray and neutron spectrometer (GRaND). In addition to these instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies (GSE).
The Dawn spacecraft was launched on September 27, 2007 on a Delta II 2925-9.5 Heavy from Cape Canaveral Air Force Station. Using its ion propulsion subsystem the spacecraft will thrust on a trajectory (Figure 1) that will have it arriving nominally at Vesta in August, 2011. Once arriving at Vesta, the spacecraft will enter a series of circular near-polar orbits. These different orbits will be varied in altitude and orientation relative to the sun to achieve the best positioning for the various observations planned. A minimum of seven months will be spent observing Vesta before departing.
After completing its data collection campaign at Vesta, the Dawn spacecraft will use its ion propulsion subsystem to leave Vesta and travel on to Ceres, making it the first spacecraft ever to orbit one extraterrestrial body, depart, and then orbit a second body. It will arrive at Ceres in February, 2015 and like its rendezvous at Vesta, it will enter a series of circular near-polar orbits.
The spacecraft will spend a minimum of five months in orbit at Ceres at various altitudes collecting science data.
Figure 1 Overview of Dawn Mission.
Dawn is an asteroid mapping mission. Each asteroid encounter has been sub- divided into three mapping phases, each at different altitudes, and each with different science objectives and primary experiments. Shortly after orbit capture the spacecraft will enter into a survey altitude mapping orbit (SAMO) where the VIR instrument is primary. This phase is relatively short, lasting for only 2-3 orbits. Global spectroscopy data and low resolution global image mosaics will be acquired during these phases at each asteroid. After SAMO, the spacecraft will be maneuvered into a high altitude mapping orbit (HAMO) where the FC instrument is primary. Medium resolution global stereo imaging will be performed at this altitude (700 km Vesta, 1200 km Ceres) while local high resolution spectroscopy data is acquired. Finally, the spacecraft will proceed to the low altitude mapping orbit (LAMO) where the GRaND and gravity experiments will collect their prime data and additional, local, high resolution imaging and spectroscopy data will be acquired. On asteroid approach, all of the instruments will perform in-flight calibrations and acquire data that will be used to characterize the hazards of the near asteroid environment (dust) and search for moons.
Chapter 2 describes the GRaND instrument, including its primary science objectives, detectors, electronics, operation, and calibration.
Chapter 3 describes the data sets, data volume, data processing and production, data flow, and scientific data validation.
Chapter 4 describes the archive volume generation, volume naming conventions, production, and PDS peer review.
Chapter 5 describes the PDS archive volume structure, the contents of each directory, and the various file naming conventions.
Chapter 6 describes the format of the EDR and RDR data files
Appendix A provides example PDS labels for the data files, index and geometry tables, and an example document label.
Appendix B lists the support staff and cognizant personnel associated with the archive generation and validation.
This specification applies to all archive volumes containing GRaND data products for the duration of its mission.
TBD
Planetary Science Data Dictionary Document, August 28, 2002, Planetary Data System, JPL D-7116, Rev. E
Planetary Data System Standards Reference, March 20, 2006, Version 3.7. JPL D- 7669, Part 2.
Planetary Data System Archive Preparation Guide, August 29, 2006, Version 1.1. JPL D-31224.
Dawn Science Data Management Plan, March, XX, 2007, DAWN-31-4032, JPL D-25901, Rev. A.
Lawrence D. J., Peplowski P. N., Prettyman T. H., Feldman, W. C., Bazell D., Mittlefehldt D. W., Reedy R. C., and Yamashita N. 2013. Constraints on Vesta’s elemental composition: Fast neutron measurements by Dawn’s gamma ray and neutron detector. Meteoritics & Planetary Science, doi:10.1111/maps.12187. Peplowski P. N., Lawrence D. J., Prettyman T. H., Yamashita N., Bazell D., Feldman W. C., and Reedy R. C. 2013. Compositional variability on the surface of 4 Vesta revealed through GRaND measurements of high-energy gamma rays. Meteoritics & Planetary Science, doi:10.1111/maps.12176.
Prettyman, T.H., W.C. Feldman, F. P. Ameduri, B. L. Barraclough, E. W. Cascio, K. R. Fuller, H. O. Funsten, D. J. Lawrence, G. W. McKinney, C. T. Russell, S. A. Soldner, S. A. Storms, Cs. Szeles, R. L. Tokar 2003, Gamma-ray and neutron spectrometer for the Dawn mission to 1 Ceres and 4 Vesta, IEEE Transactions on Nuclear Science Volume: 50, Issue: 4, 1, August 2003, pp. 1190-1197, DOI 10.1109/TNS.2003.815156.
Prettyman, T.H, W. C. Feldman, H. Y. McSween, R. D. Dingler, D. C. Enemark, D. E. Patrick, S. A. Storms, J. S. Hendricks, J. P. Morgenthaler, and K. M. Pitma 2011, Dawn’s Gamma Ray and Neutron Detector, Space Sci. Rev., Vol. 163, pp. 371-459, DOI 10.1007/s11214-011-9862-0.
Prettyman T. H., Mittlefehldt D. W., Yamashita N., Lawrence D. J., Beck A. W., Feldman W. C., McCoy T. J., McSween H. Y., Toplis M. J., Titus T. N., Tricarico P., Reedy R. C., Hendricks J. S., Forni O., Le Corre L., Li J.-Y., Mizzon H., Reddy V., Raymond C. A., and Russell C. T. (2012), Elemental mapping by Dawn reveals exogenic H in Vesta’s regolith, Science 388 242-246, http://dx.doi.org/10.1126/science.1225354
Prettyman, T. H., Mittlefehldt, D. W., Yamashita, N., Beck, A. W., Feldman, W. C., Hendricks, J. S., Lawrence, D. J., McCoy, T. J., McSween, H. Y., Peplowski, P. N., Reedy, R. C., Toplis, M. J., Le Corre, L., Mizzon, H., Reddy, V., Titus, T. N., Raymond, C. A., Russell, C. T. 2013. Neutron absorption constraints on the composition of 4 Vesta. Meteoritics & Planetary Science, doi: 10.1111/maps.12244.
Prettyman, T.H. and W.C. Feldman (2013), PDS data processing: Gamma Ray and Neutron Detector, Version 5.1, included in this volume (11-Jul-2013).
Prettyman, T.H. (2014a), Dawn’s gamma ray and neutron detector: Ephemeris, pointing & geometry at Vesta, Version 1.0, included in this volume (28-Jul-2014).
Prettyman, T.H. (2014b), Remote sensing of chemical elements using nuclear spectroscopy, in T. Spohn, D. Breuer, & T. V. Johnson (Eds.), Encyclopedia of the Solar System, Elsevier (pp. 1161-1183). ISBN 9780124158450
Yamashita N., Prettyman T. H., Mittlefehldt D. W., Reedy R. C., Feldman W. C., Lawrence D. J., Peplowski P. N., McCoy T. J., Beck A. W., Toplis M. J., Forni O., Mizzon H., Raymond C. A., and Russell C. T. 2013. Distribution of iron on Vesta. Meteoritics & Planetary Science, doi:10. 1111/maps.12139. Yamashita, N. and T.H. Prettyman (2014), Dawn’s gamma ray and neutron detector: BGO data processing, Version 3.0, included in this volume (16-Sep-2014).
This specification is useful to those who wish to understand the format and content of the GRaND PDS data product archive collection. Typically, these individuals would be scientists, data analysts, or software engineers. Details of the archive can be found in the data set catalog files and Data Processing Documents, and Prettyman et al. (2011). An overview of the archive is provided here.
The Dawn Mission's Gamma Ray and Neutron Detector (GRaND) is a nuclear spectrometer that will collect data needed to map the elemental composition of the surfaces of 4-Vesta and 1-Ceres (Prettyman, et al., 2003; Prettyman et al., 2011). Results for Vesta are given by Prettyman et al. (2012, 2013), Lawrence et al. (2013), Peplowski et al. (2013) and Yamashita et al. (2013). GRaND measures the spectrum of planetary gamma rays and neutrons, which originate from cosmic ray interactions and radioactive decay within the surface, while the spacecraft (S/C) is in orbit around each body. The instrument, which is mounted on the +Z deck of the spacecraft, consists of 21 sensors designed to separately measure radiation originating from the surface of each asteroid and background sources, including the space energetic particle environment and cosmic ray interactions with the spacecraft. The nuclear spectroscopy data provided by GRaND will be analyzed to determine the abundance of major, rock forming elements, such as O, Mg, Si, Al, Ca, Ti, and Fe; incompatible elements, including K and Th, detected by gamma ray emissions from the decay of long-lived radioisotopes; and H, C, N, and Cl, which are constituents of ices and products of aqueous alteration of silicate minerals.
Scientific objectives include:
Nuclear spectroscopy is used to determine the elemental composition of planetary surfaces and atmospheres [e.g. see Prettyman (2014b) for general review of gamma ray and neutron measurement principles]. Radiation, including gamma rays and neutrons, is produced steadily by cosmic ray bombardment of the surfaces and atmospheres of planetary bodies and by the decay of radionuclides in the regolith. The leakage flux of gamma rays and neutrons contains information about the abundance of major elements, selected trace elements, and ice constituents (e.g., H, C, and N) as well as elements associated with aqueous alteration products such as Cl. Gamma rays and neutrons can be measured at altitudes less than a planetary radius, enabling global mapping of elemental composition by an orbiting spacecraft. Radiation that escapes into space originates from shallow depths (< 1 m within the solid surface). Consequently, nuclear spectroscopy is complementary to other surface mapping techniques, such as reflectance spectroscopy, which is used to determine the mineralogy of planetary surfaces. The main benefit of gamma ray and neutron spectroscopy is the ability to reliably identify elements important to planetary geochemistry and to accurately determine their abundance. This information can be combined with other remote sensing data, including surface thermal inertia and mineralogy, to investigate many aspects of planetary science.
Nuclear reactions and radioactive decay result in the emission of gamma rays with discrete energies, which provide a fingerprint that can uniquely identify specific elements in the surface. Depending on the composition of the surface, the abundance of major rock-forming elements such as O, Mg, Al, Si, Cl, Ca, Ti, Fe, as well as Cl, a tracer of aqueous alteration, H, and elements with radioisotopes (40K, U series, Th series) can be determined from measurements of the gamma ray spectrum when they are present in detectable quantities. High energy neutrons produced by cosmic ray interactions loose energy in successive collisions with nuclei in the regolith, and are ultimately absorbed or escape into space. Their sensitivity to elemental composition depends on three main types of reactions that are important in three broad energy ranges measured by GRaND: inelastic scattering (important for fast neutrons greater than about 0.7 MeV); elastic scattering (epithermal neutrons between 0.1 eV to 0.7 MeV); and absorption (thermal neutrons less than 0.1 MeV). Fast neutrons are sensitive to the average atomic mass of the regolith when H is present in small quantities (H weight fractions less than a few hundred ppm). Epithermal neutrons are very sensitive to the abundance of H and are relatively insensitive to variations in the abundance of major elements. Thermal neutrons are sensitive to strong absorbers such as Fe, Ti, N, Cl, Gd, and Sm.
Close proximity to the planetary body is needed to measure neutrons and gamma rays because their production rate is relatively low in comparison, for example, to reflected sunlight. In addition, sensors used for gamma ray and neutron spectroscopy are generally insensitive to incident direction. Consequently, spatial resolution depends on orbital altitude, and higher resolution can be achieved by moving closer to the planet. Regional scale measurements are generally made using nuclear spectroscopy, in contrast to the meter to kilometer scale generally achieved by reflectance- and thermal emission-spectroscopy.
GRaND uses scintillator- and semiconductor-based radiation sensors to detect neutrons and gamma rays as well as energetic particles from the space environment. A scintillator is a transparent material that converts the kinetic energy of charged particles (such as electrons produced by gamma ray interactions or alpha particles and recoil protons produced by neutron reactions) into flashes of light detectable by a photomultiplier tube or photodiode. Semiconductors can be used to detect gamma rays. Swift electrons produced by Compton and photoelectric interactions ionize the semiconductor, producing electron-hole pairs. The electrons and holes drift under the influence of an applied electric field to electrical contacts. As they drift, the electrons and holes induce charge on the contacts, which can be measured by a chargesensitive preamplifier. The amplitude of the charge pulse is proportional to the energy deposited by the gamma ray, which enables semiconductors to be used for spectroscopy
The sensors and shielding/structural materials of GRaND were arranged to distinguish gamma rays and neutrons originating from the target body from those from background sources, including neutrons and gamma rays produced by cosmic rays in the bulk spacecraft, and energetic particle interactions with the instrument. The sensors on GRaND were selected to operate between -20° C and 30° C and do not require active cooling.
GRaND uses four types of radiation sensors, which are shown in the cutaway diagram of the instrument in Figure 2 (their energy ranges are summarized in Table 5):
1. Bismuth germinate (BGO) scintillator: A 7.6 (X) cm x 7.6 (Y) cm x 5.08 (Z) cm BGO crystal (approximately 300 cm3 volume) is located in the center of the scintillator subassembly. The scintillator is coupled to a 5.08 cm diameter photomultiplier tube. BGO has high density and high atomic number and is sensitive to gamma rays over a wide energy range (up to 10 MeV). The pulse height resolution at room temperature is approximately 10% full-width-at- halfmaximum (FWHM) at 662 keV.2. Cadmium Zinc Telluride (CZT) semiconductor: A planar array of 4 x 4 CZT crystals is positioned on the +Z side of the BGO crystal (Figure 2), which faces towards the asteroid during science mapping. Each crystal is 10 mm x 10 mm x 7 mm. Consequently, the array has a sensitive volume of 11.2 cm3. Coplanar grids are used to mitigate the effects of hole trapping, resulting in excellent peak shape and pulse height resolution over a wide range of energies. The pulse height resolution was better than 3% FWHM at 662 keV during laboratory testing. The array was designed to measure gamma rays with energies up to 3 MeV. The relatively high energy resolution of the CZT array enables accurate measurement of gamma rays in the densely-populated, low energy region of the spectrum, which contains gamma rays from radioactive decay and cosmic-ray induced reactions within the surface of the asteroid
3. B-loaded plastic scintillator: Two L-shaped boron-loaded plastic (BLP) scintillators (each 193 cm3) are located on the -Y and +Y sides, surrounding the sides of the BGO crystal and CZT array. The scintillators act as an anticoincidence shield to reject cosmic ray interactions. In addition, the scintillators are sensitive to neutrons. Fast neutrons (with energies greater than 700 keV) can undergo elastic scattering with H within the plastic to produce knock-on protons, which ionize the scintillator, resulting in the production of detectable light. In addition, thermal and epithermal neutrons can be captured via the 10B(n,α)7Li* reaction to produce 93 keVee light output. Note that the subscript 'ee' indicates an electron-equivalent energy, corresponding to the energy a swift electron would need in order to produce the same light output as the reaction products. The reaction product, 7Li*, produces a 478 keV prompt gamma ray. Fast neutrons with energies greater than 700 keV produce a characteristic double pulse signature, corresponding to light output from fast-neutron proton recoils followed later by neutron capture with 10B after the neutron has thermalized. The amplitude of the first pulse is related to the energy of the incident neutron. Thermal and epithermal neutrons also produce a unique coincidence signature, corresponding to 93 keVee of light produced in the plastic in coincidence with 478 keV deposited in the BGO crystal.
4. Li-glass, B-loaded-plastic phosphor sandwich (phoswich): Two BLP scintillators are located on the nadir (+Z) and spacecraft (-Z) sides of the instrument, centered on the CZT array and BGO crystal. Each BLP scintillator is approximately 10.16 cm x 10.16 cm x 2.54 cm (264 cm3) and is read out by a 2.54 cm diameter phototube. With the exception of the outward-facing side, each scintillator is covered with a sheet of Gd foil, which absorbs thermal neutrons. The outward facing side is covered by a plate of lithiated glass, 0.2 cm thick. The lithiated glass is optically-coupled to the BLP such that the phototube measures light produced in both the glass and the plastic. 6Li is a strong thermal neutron absorber. Consequently, the BLP is shielded from thermal neutrons. Epithermal neutrons that undergo capture via the 10B(n,α) reaction in the BLP produce 93 keVee. Thermal and epithermal neutrons can undergo neutron capture via the 6Li(n,t) reaction, which produces approximately 340 keVee, and is seen as a separate peak in the pulse height spectrum. Consequently, the thermal neutron signature can be determined by the weighted difference between the counting rates observed for the two reactions. Fast neutrons are measured using the double pulse signature in the BLP. In addition, the (n,γ) BLP-BGO coincidence signature provides a low-background measurement of epithermal neutrons.
FIGURE 2. Cutaway views of GRaND
Cutaway views of GRaND show the placement of subsystems and components (an XY cut is shown left and a XZ cut is shown right). The coordinate system for GRaND is the same as that of the spacecraft. GRaND is mounted on the (+X, +Y) corner of the +Z deck of the spacecraft (Figure 3). During mapping at Vesta and Ceres, the body center is in the +Z direction. The instrument coordinate system determines the naming convention of the sensors and orientation of the instrument relative to the spacecraft. The use of MZ indicates a sensor on the -Z (spacecraft-facing during mapping) side of GRaND; PZ indicates the sensor is on the +Z (asteroid when pointing nadir) side; MY indicates the sensor is on the -Y side (inboard) side of the instrument; and PY indicates the sensor is on the +Y side (outboard, towards the +Y solar panel) side of the instrument. The phototube assembly, labeled ‘PMTs’ in the figure, points along the +X axis (towards the high gain antenna). A detailed diagram of the sensor layout is provided in Prettyman et al. (2011). Artwork courtesey S. Storms of Los Alamos National Laboratory.
FIGURE 3. Location of GRaND
GRaND is mounted on the (+X, +Y) corner of the +Z deck of the spacecraft. During mapping at Vesta and Ceres, the body center is in the +Z direction.
Table 5. Approximate energy range and pulse height resolution of GRaND sensors at nominal high voltage settings.
-------------------------------------------------------------------------------------- Sensor ADC bits(1) Energy keV per Energy Threshold range (MeV) channel resolution -------------------------------------------------------------------------------------- +/-Z phos. 8 0 to 2.55 10 20%(2)/40%(3) 20 keV(4)/50 keV(5) +/-Y BLP 8 0 to 2.55 10 40%(3) 20 keV(4)/50 keV(5) BGO 10 0 to 10 10 10.5%(6) 300 keV CZT 11 0 to 4 2 3%(6) 300 keV -------------------------------------------------------------------------------------- (1) 12-bit ADCs are used for all sensors. The maximum number of high-order bits used is given. (2) Percentage full width at half maximum (FWHM) of the 260 keVee 6Li(n,t)4He reaction peak. (3) Percentage FWHM of the 93 keVee 10B(n,α)7Li reaction peak. (4) Prompt threshold; (5) delayed threshold (second interaction for fast neutrons). (6) Percentage FWHM at 662 keV (gamma rays from a 137Cs source). Note that the pulse height resolution of the CZT sensors has gradually degraded in flight from the quoted value due to radiation damage (Prettyman et al., 2011).
An electronics block diagram of GRaND is shown in Figure 4. GRaND derives power from the S/C 28Vdc power bus. The instrument low voltage power supply provides +/-5V to all the digital and analog circuits and +12V to all high voltage power sources, which supply 0 to +1500V to the photomultiplier tubes and -1500V/+70V to the CZT sensors. The instrument transmits and receives data through an RS-422 interface. The instrument is controlled by a UTMC micro-controller, which manages instrument subsystems, processes commands, monitors state of health (SOH), and processes the science data. Each of the radiation sensors is read out by analog front-end electronics, which provides shaped pulses, which are digitized by analog-todigital-converters (ADC) to determine pulse amplitude, and timing signals for analysis of coincident events. Signals from the FEE are processed by an Actel field-programmable-gatearray (FPGA). The FPGA categorizes signals from the sensors, identifying patterns that correspond to important events (for example, the fast neutron double-pulse signature). SOH data are recorded in the engineering telemetry, including high voltage values and temperatures. Commandable parameters include instrument high voltage settings, parameters used to classify coincidence events, and measurement intervals.
FIGURE 4. Instrument electronics block diagram
Each science record sent by GRaND contains counting data acquired during a collection interval, which is set by the commandable parameter TELREADOUT. The collection intervals are successive, forming a time series that can be analyzed to map elemental abundances. The records are time-tagged with the spacecraft clock (SCLK) value, which can be merged with NAIF/SPICE ephemeris data for mapping. Each science record includes scaler data, event data, and histograms. The pattern of pulses recorded by the sensors for each radiation interaction is processed by the FPGA, which categorizes the events. The events are scaled and binned into histograms. In addition, a subset of neutron and gamma ray events are recorded in a fixed length buffer. At the end of each collection interval, the data are compressed, packetized, and transmitted. The event categories recorded by GRaND are as follows (Note that event categories 3, 5, 6, and 8 were deleted during instrument development):
Category 1 (CAT1): A single pulse from the -Z or +Z phoswich. CAT1 data are binned into a histogram (256 channels) which can be analyzed to determine the areas of peaks corresponding to the 93 keVee 10B(n,α) and the 340 keVee 6Li(n,t) reactions.
Category 2 (CAT2): A prompt coincidence between the BGO and any one of the four BLP scintillators. The objective is to record thermal and epithermal neutron interactions by detecting the prompt coincidence between the deposition of 93 keVee by the 10 B(n, α)7Li* reaction products in the BLP and full energy deposition of the associated gamma ray from 7Li* → 7Li + γ, where 7Li* denotes the first excited level of 7Li. If a coincidence is detected, the FPGA checks to see if the pulse height recorded by the BGO is within a commandable coincidence window, set to bracket the 478 keV full energy peak. If so, then the pulse recorded by the BLP is binned into a 64-channel histogram that contains the 93 keVee reaction peak. Redundantly, the FPGA also checks to see if the pulse height recorded by the BLP is within a commandable coincidence window set to bracket the 93 keVee peak. If so, then the pulse recorded by the BGO is binned in a 64-channel histogram that contains the 478 keV full energy peak. Consequently, two 64channel spectra are recorded for each BLP. Since the +/-Z BLP scintillators are shielded by Gd and Li-glass, the areas of the 93 keVee and 478 keV peaks in the 64-channel histograms recorded by the CAT2 process for these two scintillators are sensitive to epithermal neutrons. The CAT2 signature for the side scintillators, which are unshielded, is sensitive to both thermal and epithermal neutrons.
Category 4 (CAT4): A double-pulse occurring in any one of the phoswich or BLP scintillators. To reduce after-pulsing, events for which the second events occur within 400 ns are rejected. The maximum time to the second pulse (TTSP) recorded by GRaND is 25.6 microseconds. The amplitudes of the first and second pulse and the TTSP are recorded as list mode data in a fixed length buffer. The total number of CAT4 events processed by the FPGA during the collection interval is recorded in the scaler data. The CAT4 data can be analyzed to determine the flux and energy distribution of fast neutrons.
Category 7 (Cat7): A coincidence between a single CZT sensor and the BGO scintillator. The CZT pulse height (digitized by a 12-bit ADC) and CZT-sensor- ID are recorded as event data in the gamma event buffer. The BGO pulse height is recorded as a 9 bit unsigned integer. The portion of the gamma event buffer reserved for CAT7 events is commandable. The CAT7 data can be used to discriminate gamma rays originating from the target body and the spacecraft. For example, gamma rays originating from the target body (from nadir) can undergo low angle Compton scattering in a CZT sensor prior to entering the BGO crystal, where they may deposit the rest of their energy. The energy of the gamma ray can be determined by summing the pulse heights measured by the CZT and BGO sensors. Gamma rays originating from the spacecraft are shielded from the CZT array by the BGO crystal. In addition, those originating from the spacecraft that interact with a CZT sensor must scatter through a large angle, depositing a relatively large amount of energy in the CZT sensor before reaching the BGO crystal. Consequently, summing the energy deposited in the CZT and BGO sensors for events in which the energy deposited in the BGO sensor is greater than the energy deposited in the CZT sensor tends to reject gamma rays originating from the spacecraft.
Category 9 (CAT9): A single pulse from the BGO scintillator. The CAT9 events are recorded as a 1024 channel pulse height spectrum.
Category 10 (CAT10): A single interaction with a CZT sensor, in which one of the 16 CZT sensor records a pulse and none of the other sensors on GRaND (including BGO, BLP, etc..) are triggered. The pulse height (digitized by a 12- bit ADC) and CZT-sensor-ID are recorded as list-mode data in a fixed length buffer. The total number of CAT10 events processed by the FPGA during the collection interval is recorded in the scaler data. The CAT10 list mode data can be processed, given the known energy calibration for each of the sensors, to form a composite pulse height spectrum. During mapping, the CAT9 histogram and CAT10 composite spectrum contain full energy peaks corresponding to radioactive decay and nuclear reactions occurring within the planetary surface, which can be analyzed to determine elemental abundances.
Summary of Event Categories -------------------------------------------------------------------------------- CAT1 A single pulse from either the –Z or +Z phoswich recorded in 256-channel histograms. Sensitive to thermal and epithermal neutrons. CAT2 Coincidence between the any of the four BLP scintillators and the BGO sensor. Pairs of 64-channel histograms are recorded for each BLP-BGO combination (e.g. +Z phoswich – BGO). Sensitive to thermal and epithermal neutrons. CAT4 Double pulse in the BLP sensors. The amplitude and ID of the BLP sensor for the first and second pulses is recorded along with the time between pulses in the neutron event buffer. Sensitive to fast neutrons. CAT7 Coincidence between the BGO and any one of the 16 CZT sensors. The CZT pulse amplitude, sensor ID, and the BGO pulse amplitude are recorded in the gamma event buffer. Useful, for example, for pair spectroscopy. CAT9 A single pulse from the BGO sensor binned into a 1024-channel histogram. Sensitive to gamma rays up to about 10 MeV. CAT10 A single pulse from any one of the 16 CZT sensors. The pulse amplitude and sensor ID is recorded in the gamma event buffer along with the CAT7 data. The only distinguishing characteristic between CAT7 and CAT10 is that the BGO pulse amplitude is greater than 0 for CAT7 and 0 for CAT10. Sensitive to gamma rays up to about 3 MeV. --------------------------------------------------------------------------------
GRaND has three operational modes:
1. STANDBY;
2. NORMAL; and
3. ANNEAL.
The instrument starts in STANDBY mode. In STANDBY mode, the radiation sensors are not operational (all commands are accepted except high voltage enable commands). Only SOH data are generated in standby mode. Data from the temperature sensors are recorded in STANDBY if the +/-5V low voltage supply is activated. From STANDBY, the instrument can be commanded to NORMAL mode for which all commands are accepted. In NORMAL mode, the instrument can be configured for science data acquisition, including enabling and setting the high voltage level for each sensor. Both SOH and science data are included in the telemetry. From STANDBY, the instrument can also be commanded to ANNEAL mode, which is designed to anneal radiation damage accrued by the CZT crystals (Prettyman et al., 2003). Only SOH data are generated in ANNEAL mode.
Science data will be acquired by GRaND during cruise, Mars Flyby, and mapping of Vesta and Ceres. In order to acquire science data, GRaND must be in NORMAL mode with high voltages turned on and adjusted to nominal settings. Large gaps in the data are expected during cruise, when the instrument is off. For science mapping, only data acquired when the instrument bore-sight is pointed to within 5-deg of body center are used. In addition, solar energetic particle events are reported separately from data acquired during quiet conditions. Contamination from other instruments and spacecraft subsystems appears to be negligible, but will be evaluated throughout the mission.
Calibration data for GRaND were acquired during assembly, test, and launch operations (ATLO), before and after delivery of the instrument for integration with the spacecraft. Prior to delivery, the instrument was characterized at a calibration facility at Los Alamos National Laboratory and on the bench using neutron and gamma ray sources. The main goals of the calibration exercise were to verify the functionality of each of the sensors; determine the energy calibration for each sensor and event category; determine the absolute calibration (relationship between flux and counting rate) for each sensor and event category as a function of incident energy and direction. Data acquired during comprehensive performance tests (CPTs) following integration of GRaND with the spacecraft provide supplemental information needed to confirm the energy calibration.
Data acquired by GRaND during cruise and Mars Gravity Assist are useful for instrument calibration as well as characterization of the energetic particle background during periods of low solar activity, which are representative of data used for mapping (solar energetic particle events are excluded). The close fly by of Mars by Dawn provided a valuable data set that can be compared directly to data acquired by the Mars Odyssey Gamma Ray and Neutron Spectrometer subsystems, enabling cross-calibration of GRaND with Mars Odyssey (see Prettyman et al., 2011 for details). Cruise data acquired before and after encounters with Ceres and Vesta will be used to assess the buildup of induced radioactivity with GRaND, if detectable.
The structure and content of the Level 1A and 1B data sets are described in detail in their respective catalog files. Data processing steps as well as a thorough presentation of the data products are described in Prettyman et al. (2011) and in Data Processing Documents for the EDR and each RDR data set.
A summary of data files included in the Level 1A and 1B archives are provided in the following table:
Table 6. Standard Data Products -------------------------------------------------------------------------------- Data Set ID |Standard |Standard Product Description |Data | |Products | -------------------------------------------------------------------------------- |AUX_RDG |Instrument readings file: a time-ordered list of | |temperature and voltage readings averaged over | |each state-of-health accumulation interval | |(TELSOH), converted to physical units. |------------------------------------------------------------------ |AUX_SCI-SCL |Science scaler data: a time-ordered list of the | |scaler data recorded in the science telemetry. | |The accumulation interval for the scalers is | |TELREADOUT. |------------------------------------------------------------------ |AUX_SOH-SCL |State of health scaler data: a time-ordered list | |of the scaler data recorded in the state-of- | |health telemetry. The accumulation time for the | |scaler data is TELSOH. Note that the scalers are | |reset at the end of each science accumulation | |interval (TELREADOUT). If the state-of-health | |accumulation interval is selected to subsample | |the science interval, then the state-of-health DAWN-X- | |scalers can be used to detect and correct for GRAND-2-EDR- | |rollover of the science scalers, such as the dead CRUISE- | |time counter. COUNTS-V1.0 |------------------------------------------------------------------ |AUX_STA |Instrument state file: the instrument settings, or | |including the mode, power supply states, high | |voltage settings, the data accumulation interval, DAWN-M- | |and coincidence windows. The first record of the GRAND-2-EDR- | |state-of-health file is recorded in the state MARS- | |file, stamped with SCET UTC. Thereafter, rows are COUNTS-V1.0 | |added only when the instrument settings change. |------------------------------------------------------------------ |GAMMA_BGO |time-ordered list of pulse height spectra (1024 | |channels with units of uncorrected | |counts/channel) acquired by the BGO sensor |------------------------------------------------------------------ |GAMMA_EMG |gamma ray event data as a binary time series |------------------------------------------------------------------ |NEUTRON_BG02_MY |time-ordered lists of the 64-channel CAT2 BGO | |pulse height spectra for coincidences with the | |BGO and the BLP –Y sensor |------------------------------------------------------------------ |NEUTRON_BG02_PY |time-ordered lists of the 64-channel CAT2 BGO | |pulse height spectra for coincidences with the | |BGO and the BLP +Y sensor |------------------------------------------------------------------ |NEUTRON_BG02_MZ |time-ordered lists of the 64-channel CAT2 BGO | |pulse height spectra for coincidences with the | |BGO and the BLP –Z sensor |------------------------------------------------------------------ |NEUTRON_BG02_PZ |time-ordered lists of the 64-channel CAT2 BGO | |pulse height spectra for coincidences with the | |BGO and the BLP +Z sensor |------------------------------------------------------------------ |NEUTRON_BLP2_MY |time-ordered lists of the 64-channel CAT2 BLP | |pulse height spectra for coincidences with the | |BGO and the BLP –Y sensors |------------------------------------------------------------------ |NEUTRON_BLP2_PY |time-ordered lists of the 64-channel CAT2 BLP | |pulse height spectra for coincidences with the | |BGO and the BLP +Y sensor |------------------------------------------------------------------ |NEUTRON_BLP2_MZ |time-ordered lists of the 64-channel CAT2 BLP | |pulse height spectra for coincidences with the | |BGO and the BLP –Z sensor |------------------------------------------------------------------ |NEUTRON_BLP2_PZ |time-ordered lists of the 64-channel CAT2 BLP | |pulse height spectra for coincidences with the | |BGO and the BLP +Z sensor |------------------------------------------------------------------ |NEUTRON_EMN |the neutron event data as a binary time series. |------------------------------------------------------------------ |NEUTRON_PHOS_MZ |time-ordered lists of the 256-channel CAT1 pulse | |height spectra for the -Z phoswiches. Note that | |the naming convention for the top, bottom, and | |side scintillators is determined by the | |instrument coordinate system. |------------------------------------------------------------------ |NEUTRON_PHOS_PZ |time-ordered lists of the 256-channel CAT1 pulse | |height spectra for the +Z phoswiches. Note that | |the naming convention for the top, bottom, and | |side scintillators is determined by the | |instrument coordinate system. -------------------------------------------------------------------------------- |-TSI-EPM* |time series of ephemeris and pointing data, | |including the total livetime, the distance and | |direction to body center, the velocity of the | |spacecraft rotated into the reference frame of the | |instrument, the subsatellite position and | |altitude, and the fractional solid angle subtended | |by the body at the spacecraft. In addition, the | |average counting rate for the 'coincidence of | |three or more sensors' scaler (SCALER_SCI[15]) is | |provided as an indicator of the interaction rate | |of galactic cosmic rays. DAWN-M- |------------------------------------------------------------------ GRAND-2-RDR- |-TSI-NCR |time series of neutron counting rates determined MARS-COUNTS- | |from CAT1, CAT2, and CAT4 pulse height spectra. V1.0 | |Counting rates sensitive to neutrons in the | |thermal, epithermal, and fast energy ranges are | |provided. Propogated uncertainties (1-sigma) are | |provided. |------------------------------------------------------------------ |-TSI-GCR |time series of net areas for selected full energy | |interaction peaks from the pulse height spectrum | |acquired by the BGO sensor. Propogated | |uncertainties (1-sigma) are provided. |------------------------------------------------------------------ |-TSI-BGO |time series of BGO 1024-channel pulse height | |spectra that have been adjusted so that the | |offset is 0 keV with a slope of 8.9 keV/channel. | |Note that the method for determining the | |uncertainty in the counting rates for each channel | |is provided in the format file. -------------------------------------------------------------------------------- |-EPG |time series of spacecraft ephemeris, pointing, | |and measurement geometry (EPG) for each and every | |science data record acquired by GRaND during | |Vesta encounter. The time series includes live | |time, instrument configuration, and the triples | |counting rate, used as a proxy for the galactic | |cosmic ray flux. The spacecraft clock (SCLK) is | |used as a serial number to cross reference EPG DAWN-A- | |information with science data in EPG and RDR VESTA-COUNTS-| |files. V1.0 |------------------------------------------------------------------ |-PHS-BGOC |time series of corrected and energy calibrated | |BGO pulse height spectra for suitable for use in | |geochemical studies (elemental ID and | |quantification). --------------------------------------------------------------------------------
*TSI refers to the type of time series: central moving average (CMA) or decimated time series (DTS). As described in Prettyman and Feldman (2010), the Level1b data are represented as a time series in which counting rates and spectra are averaged over a time-window, consisting of an odd number of science accumulation intervals, selected by the evaluator. Two types of time series are possible: a CMA, in which the averaging window is centered on each point in the original time series, and a result is reported for each science accumulation interval; and a DTS, in which the averaging window is shifted forward in time by its width, resulting a data set that has fewer points than the original time series. The CMA is intended for mapping, for example, in cases where full sampling of rapidly changing counting rates and solid angles is needed. The DTS is useful for averaging over long periods of time, for example, during cruise, when counting rates are not changing rapidly. By averaging over long time intervals, the DTS can be used to produce high precision gamma ray spectra needed for accurate peak identification, analysis, and calibration.
Level 2 maps of Vesta’s composition were developed by the Dawn Geochemistry team. These were submitted to the PDS and have been certified. Maps include the abundance of H, Fe, thermal, epithermal, fast, and high-energy-gamma-ray counting rates.
The DSC captures all of the payload instrument telemetry frames as binary files after the data have been cleaned up in the post-pass processing (reconstructed level-0 data). Post-pass processing is completed with 8 hours of each pass and typically is able to fix minor form of data corruption (partial packet reconstruction, dropped time tags, etc.). These files are inventoried within the Dawn Science Database (DSDb) and made available to the teams for download at any time. The DSC prepares the documentation and metadata required in order to submit these products to the PDS to be saved (rather than archived). The PDS documentation threshold for saved data sets is substantially lower than for archived products. The raw decoded frames are not considered to be useful for the general science community but the bits will be preserved in their rawest form. The DSC will submit the telemetry frames to the PDS Small Bodies Node (SBN) within a week of the end of each science phase. All level-0 data products are created with PDS 'minimum' labels. Each level-0 data file contains the CCSDS packets for a single APID.
The Doppler Tracking data are used by the NAV and Gravity Science teams and do not flow into the TDS. These data flow from the DSN into the OSCAR-X system where they are accessible to the gravity team at JPL. Since these data do not flow directly into the DSC, the DSC staff will manually retrieve them from OSCAR-X and load them into the DSDb. Gravity Science investigators that are not at JPL will use the DSDb to retrieve the level-0 data for their analysis. This process is described in the operational interface agreement (OIA-DSC-409) between the Gravity Science Team and the DSC. Unlike the decoded frames, the level-0 Doppler Tracking data are archived with the PDS. DSC prepares these data for archive and submits them to the PDS SBN at the same time as the level-1A data products from the payload instruments.
Figure 5 Dawn Science Data Flow. SPAA elements and products are outlined with solid black lines, MOS components with dotted lines, and PDS components with dashed lines.
The GRaND Level 1 data processing steps are described in detail in Prettyman et al. (2011) and the Data Processing Documentincluded in this archive.
The GRaND EDR are a time-ordered collection of gamma ray and neutron counting data and histograms acquired by GRaND during different phases of the Dawn Mission, including assembly-test-and-launch-operations (ATLO), cruise, Mars Gravity Assist (MGA), and science mapping at 4-Vesta and 1-Ceres. The dataset also includes state-of-health data (instrument settings, temperature and voltage readings) needed for scientific analysis of the neutron and gamma ray data. The EDR is an intermediate data product (Level 1A) that is derived from Raw Data Records (Level 0) using reversible operations. The Level 1A data are the lowest level of GRaND data archived in the PDS, from which all higher order data sets are derived. To support timely delivery of higher order products, the Level 1A data are processed using an automated pipleline, which operates on Level 0 data when it is queried by the DSC.
The data set consists primarily of ASCII tables, divided into three functional categories: auxilliary information (AUX); gamma ray spectra and event data (GAMMA); and neutron spectra and event data (NEUTRON). Gamma ray and neutron event data are recorded in binary files. Some of the data in the ASCII files, which are human-readable, are repeated in the binary files to aid in the verification of user-written routines.
The Level 1A data are automatically processed using a pipeline, which operates on files queried by the DSC over selected time intervals. Each DSC query separates the GRaND data into files containing state-of-health and science data records, in the order in which they were received on the ground and with corrupted packets removed. The state-of-health data are further divided into real time telemetry data and playback data. The science data are stored in a single raw data file.
The pipeline merges the state-of-health data from the playback and realtime files to produce a time-ordered-list of records. Selected data are extracted to produce the Level 1A AUX files. Internal temperature readings are converted from data numbers (DN) to engineering units using a linear function determined during ground calibration: T (degrees C) = 0.4354 DN - 32.267. The high voltage readings for the high voltage power supplies are reported in engineering units using the conversion V (Volts) = 1500 DN/255. The CZT differential bias voltage is converted using V (Volts) = 0.405 DN.
The science data are decompressed, decoded, separated by functionality and written as time-ordered ASCII tables and binary time series. The raw histograms (CAT1, CAT2, and CAT9) are represented as 8 bit numbers which are decompressed and reported as 16 bit, unsigned integers.
The GRaND Reduced Data Records (RDR) are a time-ordered collection of corrected gamma ray and neutron counting data and calibrated pulse height spectra acquired by GRaND during Mars Gravity Assist (MGA). Similar products will be developed for science mapping at 4-Vesta and 1-Ceres and for data acquired during cruise. The RDR is a calibrated data product (Level 1B) that is derived from Experimental Data Records (EDR, Level 1A). The objective of the RDR is to provide counting rates and ancillary pointing and ephemeris data needed for mapping. The ancillary data includes the sub-satellite point, the distance and direction to body center, and the spacecraft velocity vector at Mars, which is needed to account for the motion of low energy (thermal and epithermal) neutrons relative to the spacecraft. In the current version of the data set, counting rates and fluxes corrected for altitude and spacecraft motion, which require knowledge of the instrument response, are not provided; however, future versions of the RDR, especially for Vesta and Ceres mapping will include counting rates corrected for solid angle and pointing as well as incident gamma ray and neutron fluxes.
Processing steps for the RDR data set generally include the following (refer to the specific data set catalog and data reduction documents associated with each data volume for details):
The data set consists of ASCII tables, divided by functionality into four categories: ephemeris, pointing, and geometry data; neutron counting rates (NCR); gamma ray counting rates (GCR), and the BGO pulse height spectrum (BGO). The fast neutron flux spectrum (with units of neutrons/cm2/s/MeV), which can be unfolded from the fast neutron pulse height spectrum given the response function, and CZT composite spectrum will be included in future releases.
Higher order data products envisioned for GRaND are described by Prettyman et al. (2011). Level 2 products from Vesta encounter were developed by the Geochemistry team and archived by the PDS. The Level 2 products are based on studies published in the scientific literature (Prettyman et al., 2012; 2013; Lawrence et al., 2013; Peplowski et al., 2013, Yamashita et al., 2013).
The Instrument Teams retrieve the reconstructed Level-0 data from the DSDb and use it to produce the Level-1A (raw, reformatted) data sets. The raw telemetry data are decompressed, decoded, and formatted into scientifically useful data structures. These products, along with their required PDS documentation, form the level-1A data sets (EDRs). The Instrument Teams extract the reconstructed spacecraft ephemeris and pointing data (SPICE kernels) from the DSDb and use these data to compute the various geometry data that are included in the PDS labels associated with each data product. The Instrument Teams are required submit the PDS labeled EDRs to the DSDb within 7 days after the reconstructed data are made available to the teams (see OIA-DSC-406, OIA-DSC-407, OIA-DSC-408). These data are then available to the rest of the Science Team.
The DSC prepares the level-1A data for archive with the PDS SBN. If the spacecraft ephemeris or pointing reconstruction is improved after the data products are submitted to the DSDb, the DSC will update the geometry information in the labels in the DSDb prior to generating the archive. The DSC extracts the data and documentation files associated with each instrument data set from the DSDb and organizes them according to PDS volume organization standards (JPL-D- 7669). Each level-1A data set will be archived on a separate PDS volume set. The DSC will produce and deliver the volumes to the PDS SBN in accordance with the SBN standard data delivery practices at the time of each delivery. Presently, the PDS SBN accepts volumes delivered electronically, on CDROM, and on DVD-R. EDR data volumes are to be delivered to the PDS SBN within 90 days of the end of each science phase (Approach, Survey, HAMO, LAMO, etc.). The DSC is responsible for following the archive submissions through the PDS peer review process until the data are finally accepted into the PDS archive. The Instrument Teams will support the DSC during this PDS process by providing any additional documentation that is requested by the PDS peer review panel.
Additional data processing is performed by the instrument teams to produce calibrated level 1B (RDR) data products (radiometrically corrected images and spectra and fluxes from the GRaND instrument). The Instrument Teams use the level-1A (EDR) data sets they have provided to the DSDb as the input to the data processing pipeline that produces the level-1B (RDR) data set. The RDR data products are submitted to the DSDb within 14 days of the receipt of the corrected telemetry by ground data system. If during the course of the mission an improved calibration becomes available, the Instrument Teams may choose to update the data in the DSDb using the latest version of the calibration. The Instrument Teams are not obligated to provide updated RDR data products and any such resubmission would be negotiated with the Science Team. The DSDb system supports the resubmission of data sets.
The DSC also prepares the level-1B data for archive with the PDS SBN. The DSC xtracts the latest data and documentation files associated with each instrument ata set from the DSDb at the time of submission and organizes them according to PDS volume organization standards (JPL-D-7669). Each level-1B data set will be archived on a separate PDS volume set. The DSC will produce and deliver the volumes to the PDS SBN in accordance with the SBN standard data delivery practices at the time of each delivery. RDR data volumes are to be delivered to the PDS SBN within 6 months after asteroid departure. The DSC and Instrument Teams will support the PDS peer review process of the RDR data sets in the same manner as the EDR data sets.
The instrument team carries out a scientific analysis of the data and a technical analysis of the instrument performance to identify any issues that might affect the quality of the science data. The instrument team continuously improves the quality and content of the archived data to address mission science objectives. The team monitors telemetry and optimizes instrument settings to provide the highest quality scientific data.
A complete scientific validation of the data is taking place during the proprietary period as the GRaND and Geochemistry teams perform scientific analyses of the data and examines in detail the content of each data product.
----------------------------------------------------------------------------- Table 7: GRaND Data Product Archive Schedule ----------------------------------------------------------------------------- Instrument Data Product Provider Mars Vesta Ceres ----------------------------------------------------------------------------- Level 0 DSC EDA EDA EOO --------------------------------------------------------------- EDR - Level 1A Inst EDA + 3 m EDA + 3 m EDA + 1 m GRaND --------------------------------------------------------------- RDR - Level 1B Inst D + 6 m D + 5 m EOO + 3 m --------------------------------------------------------------- Derived Products Inst D + 12 m D + 12 m EOO + 5 m ----------------------------------------------------------------------------- m - months EDA - End of data acquisition EOO - End of operations D - Asteroid departure
The DSC collects the data files and labels provided by the GRaND team onto archive volumes. Each archive volume contains all GRaND data available for the time interval covered by the archive volume. Once all of the data files, labels, and ancillary data files are organized onto an archive volume, the DSC adds all of the PDS required files (AAREADME, INDEX, ERRATA, etc.) and produces the physical media.
This section describes the format of GRaND standard product archive volumes. Data that comprise the GRaND standard product archives will be formatted in accordance with Planetary Data System specifications [Planetary Science Data Dictionary, 2002; Planetary Data System Archive Preparation Guide, 2006; PDS Standards Reference, 2007].
Disk formats for the archive volumes will conform to the PDS standard for the applicable media. At present, the plan is to archive GRaND data on DVD-R media. The PDS standard for DVD-R media disk format is ISO-UDF Bridge.
Data are organized so that one GRaND data set will coincide with a single logical volume.
---------------------------------------------------------- Table 8: GRaND Data Sets and corresponding Volume ID’s ---------------------------------------------------------- Data Set Name Volume ID ---------------------------------------------------------- DAWN-X-GRAND-2-EDR-CRUISE-COUNTS-V1.0 DWNXGRD_1A DAWN-M-GRAND-2-EDR-MARS-COUNTS-V1.0 DWNMGRD_1A DAWN-A-GRAND-2-EDR-VESTA-COUNTS-V1.0 DWNVGRD_1A DAWN-A-GRAND-2-EDR-CERES-COUNTS-V1.0 DWNCGRD_1A DAWN-M-GRAND-3-RDR-MARS-COUNTS-V1.0 DWNMGRD_1B DAWN-M-GRAND-3-RDR-VESTA-COUNTS-V1.0 DWNVGRD_1B DAWN-M-GRAND-3-RDR-CERES-COUNTS-V1.0 DWNCGRD_1B ----------------------------------------------------------
The peer review panel consists of members of the instrument team, the DSC, and members of the PDS Small Bodies and Engineering Nodes, and at least two outside scientists actively working in the field of asteroid remote sensing science. The DSC is responsible for generating and delivering PDS compliant volumes to the SBN. The PDS personnel are responsible for verifying that the volume(s) are fully compliant with PDS standards. The instrument team and outside science reviewers are responsible for verifying the content of the data set, the completeness of the documentation, and the usability of the data in its archive format. The peer review process is a two part process. First, the panel reviews this document and verifies that a volume produced to this specification will be useful. Next, the panel reviews a specimen volume to verify that the volume meets this specification and is indeed acceptable.
If the peer review decides that there are issues (liens) to be solved, these liens are first discussed and whenever possible clarified with the instrument team. If the liens are accepted by the team the necessary modifications are performed and the datasets are redelivered.
This section describes the contents of the GRaND standard product archive collection volumes, including the file names, file contents, file types, and organizations responsible for providing the files. The complete directory structure is shown in Appendix A. All the ancillary files described herein appear on each GRaND archive volume, except where noted.
The following files are contained in the root directory, and are produced by the DSC at UCLA. With the exception of the hypertext file and its label, all of these files are required by the PDS Archive Volume organization standards.
-------------------------------------------------------------------------------------------- Table 9: Root Directory Contents -------------------------------------------------------------------------------------------- File Name File Contents File Provided By -------------------------------------------------------------------------------------------- AAREADME.TXT This file completely describes the Volume DSC organization and contents (PDS label attached). AAREADME.HTM Hypertext version of AAREADME.TXT (top level of DSC HTML interface to the Archive Volume). AAREADME.LBL A PDS detached label that describes AAREADME.HTM. DSC ERRATA.TXT A cumulative listing of comments and updates concerning DSC all GRaND Standard Data Products on all GRaND Volumes in the Volume set published to date. VOLDESC.CAT A description of the contents of this Volume in a PDS DSC format readable by both humans and computers. --------------------------------------------------------------------------------------------
The following files are contained in the INDEX directory and are produced by the DSC. The INDEX.TAB file contains a listing of all data products on the archive volume. In addition, there is a cumulative index file (CUMINDEX.TAB) file that lists all data products in the GRaND archive volume set to date. The index and index information (INDXINFO.TXT) files are required by the PDS volume standards. The index tables include both required and optional columns. The cumulative index file is also a PDS requirement; however, this file is not reproduced on each data volume. An online and web accessible cumulative index file is maintained at the DSC while archive volumes are being produced. Only the last archive volume in the volume series will contain a cumulative index file.
-------------------------------------------------------------------------------------------- Table 10: INDEX Directory Contents -------------------------------------------------------------------------------------------- File Name File Contents File Provided By -------------------------------------------------------------------------------------------- CUMINDEX.TAB A table listing all Data Products in the GRaND DSC Archive volume CUMINDEX.LBL A PDS detached label that describes CUMINDEX.TAB DSC INDXINFO.TXT A description of the contents of this directory DSC INDEX.TAB A table listing all GRaND Data Products on this Volume DSC INDEX.LBL A PDS detached label that describes INDEX.TAB DSC --------------------------------------------------------------------------------------------
The completed PDS catalog files in the CATALOG directory provide a top-level understanding of the Dawn/GRaND mission and its data products. The information necessary to create the files is provided by the GRaND team and formatted into standard template formats by the DSC. The files in this directory are coordinated with the data engineers at both the DSC and the PDS SBN.
-------------------------------------------------------------------------------------------- Table 11: CATALOG Directory Contents -------------------------------------------------------------------------------------------- File Name File Contents File Provided By -------------------------------------------------------------------------------------------- CATINFO.TXT A description of the contents of this directory DSC grand_XXX_YYY_ds.cat PDS Data Set description file. XXX is the NASA GRaND Team data processing level of the data (e.g. “l1a”, “l1b”, etc.), and YYY is the mission phase or target (e.g. “cruise”, “vesta”, etc.). dawninsthost.cat PDS instrument host (spacecraft) catalog DSC description of the Dawn spacecraft grand_instrument.cat PDS instrument catalog description of the GRaND GRaND Team instrument dawnmission.cat PDS mission catalog description of the Dawn DSC mission grand_person.cat PDS personnel catalog description of GRaND Team GRaND Team members and other persons involved with generation of GRaND Data Products grand_ref.cat GRaND-related references mentioned in other *.CAT GRaND Team files --------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------- Table 12: CALIB Directory Contents -------------------------------------------------------------------------------------------- File Name File Contents File Provided By -------------------------------------------------------------------------------------------- CALINFO.TXT A description of the contents of this directory GRaND Team --------------------------------------------------------------------------------------------
The DATA directory contains the actual Data Products produced by the GRaND team.
Every file in the DATA path of an Archive Volume is described by a PDS label. Data files have detached PDS labels. Text documentation files have detached labels. Detached PDS label files have the same root name as the file they describe but have the suffix ".LBL".
The data directories are organized in the same way.
-------------------------------------------------------------------------------------------- Table 13: DATA Directory Contents -------------------------------------------------------------------------------------------- File Name File Contents File Provided By -------------------------------------------------------------------------------------------- DATAINFO.TXT A description of the contents of this directory DSC (see section Data files GRaND Team 5.5.3) --------------------------------------------------------------------------------------------
All data product files throughout different GRaND data sets will be named using the same file naming convention. The basic naming convention is as follows:
GRD-L1X-Y1M1D1-Y2M2D2_YCMCDC-TTTTTTT.EXT
where:
X ‘A’ or ‘B’ to indicate EDR or RDR, respectively. Y1M1D1 SCET UTC date for first science data record Y2M2D2 SCET UTC date for last science data record YCMCDC data product creation date TTTTTTT file type. For the EDR, possible values include the following: STA = instrument state file (auxiliary) RDG = instrument readings file (auxiliary) SOH-SCL = state of health scaler data (auxiliary) SCI-SCL = science scaler data (auxiliary) BGO = time-ordered pulse height spectra acquired by BGO BGOC = time-series of gain-corrected BGO gamma ray spectra EMG = gamma ray event data EMN = neutron event data EPG = time-series of ephemeris, pointing & geometry data PHOS_MZ = time-ordered CAT1 pulse height spectra (-Z phoswiches) PHOS_PZ = time-ordered CAT1 pulse height spectra (+Z phoswiches) BGO2_MY = time-ordered CAT2 BGO pulse height spectra for coincidences with BGO and BLP –Y sensor BGO2_PY = time-ordered CAT2 BGO pulse height spectra for coincidences with BGO and BLP +Y sensor BGO2_MZ = time-ordered CAT2 BGO pulse height spectra for coincidences with BGO and BLP –Z sensor BGO2_PZ = time-ordered CAT2 BGO pulse height spectra for coincidences with BGO and BLP +Z sensor BLP2_MY = time-ordered CAT2 BLP pulse height spectra for coincidences with BGO and BLP –Y sensor BLP2_PY = time-ordered CAT2 BLP pulse height spectra for coincidences with BGO and BLP +Y sensor BLP2_MZ = time-ordered CAT2 BLP pulse height spectra for coincidences with BGO and BLP –Z sensor BLP2_PZ = time-ordered CAT2 BLP pulse height spectra for coincidences with BGO and BLP +Z sensor EXT file extension: TAB for ASCII files, DAT for binary files
The EDR data are derived from Level 0 raw data queried by the DSC over irregular time periods, generally determined by the pattern of downlinks from the spacecraft. The DSC divides the Level 0 data into separate files containing state of health and science data packets. The Level 1A pipeline operates on these files to produce the Level 1A archive. The directory structure for the Level 1A data is given by
GRD-L1A-Y1M1D1-Y2M2D2_YCMCDC (top level directory)
LEVEL1A_AUX (directory containing auxiliary data)
LEVEL1A_GAMMA (directory containing gamma ray counting data)
LEVEL1A_NEUTRON (directory containing neutron counting data)
The top level directory name contains the SCET UTC dates for the first and last science data records (Y1M1D1 and Y2M2D2, respectively), and the creation date (YCMCDC) for the archive. For example, for GRD-L1A-090217-090218_090517, the first science data record was acquired on 17-Feb-2009. The last science data record was acquired on 18-Feb-2009. The archive was created by the pipeline on 17-May-2009.
The LEVEL1A_AUX directory contains the following files derived from the Level 0 state-ofhealth and science data:
For each science and state of health record, values for 23 scalers are recorded in the -SCISCL.TAB and -SOH-SCL.TAB files, respectively.
The scalers provide the following information:
------------------------------------------------------------------------- Table 14: EDR Data Scaler Descriptions ------------------------------------------------------------------------- Index Name Description ------------------------------------------------------------------------- 0 D0 Dead time counts 1 OBGO BGO overload events 2 OCZT CZT overload events 3 O+Z +Z phoswich overload events 4 O-Y -Y BLP overload events 5 O+Y +Y BLP overload events 6 O-Z -Z phoswich overload events 7 C+Z +Z phoswich CAT4 events 8 C-Y -Y BLP CAT4 events 9 C+Y +Y BLP CAT4 events 10 C-Z -Z phoswich CAT4 events 11 CESI Early second interaction events 12 CMC Multiple-crystal CZT events 13 C10 Valid CZT events (CAT10) 14 C7 Coincidence BGO and CZT events (CAT7) 15 CMS Coincidence of three or more sensor elements 16 T Total events processed by GRaND 17 N10 Number of single CZT events (CAT10) in the gamma ray event buffer 18 N7 Number of BGO-CZT coincidence events (CAT7) in the gamma ray event buffer 19 NNE Number of events (CAT4) in the neutron event buffer 20 MG Total number of events allowed in the gamma ray event buffer 21 M10 Number of single CZT events (CAT10) allowed in the gamma ray event buffer 22 MNE Number of events allowed in the neutron event buffer -------------------------------------------------------------------------
Note that indices 0 through 19 are for 16-bit counters, which are reset at the end of every science accumulation interval specified by TELREADOUT. If the state-of-health accumulation interval is adjusted to subsample the science accumulation interval (for example, TELREADOUT = n * TELSOH, where n is a whole number), then the scalers will monotonically increase during each acquisition interval, unless overflow occurs. A rollover counter is not provided; however, for situations in which the counting rate is high or the accumulation intervals are large, the number of rollovers for individual scalers can be determined from the SOH scaler data if TELSOH is set to subsample the science accumulation interval (Prettyman et al., 2011). In situations where the counting rate is changing, abrupt changes in the scaler values can also indicate that rollover has occurred. Rollover is treated in the production of the Level1B RDR data.
Indices 20 through 21 are maximum values for the number of events that can be recorded in the event buffers. The number of gamma ray and neutron events is commandable and can be adjusted. The total number of gamma ray and neutron events must be less than 6677.
The LEVEL1A_GAMMA directory contains the following science data files:
The LEVEL1A_NEUTRON directory contains the following science data files:
The instrument state file provides a complete list of the instrument settings from the SOH telemetry for data within a selected Level1A directory. As such, the state file is crucial for understanding instrument activities and identifying periods of time during which science data were acquired. For example, consider the state file for the Mars Gravity Assist directory, GRD-L1A- 090217-090218_100930, which corresponds to the 09051_dawn\ entry in Table 4 of the Data Processing Document and MVC0 in Table 8 of Prettyman et al. (2011). In the subdirectory LEVEL1A_AUX, look at the file named GRD-L1A-090217- 090218_100930-STA.TAB. The first eight columns of the .STA file follow (the column definitions are given in GRD_L1A-STATE.FMT):
STATE DELTA HVPS1 SCET_UTC INDEX SCLK SCLK TELREADOUT TELSOH MODE SET 2009-02-17T16:58:00 0 19800 288161947 70 35 1 1058.82 2009-02-17T22:28:00 1 0 288181747 2000 35 1 1058.82 2009-02-17T22:28:00 2 8460 288181747 35 35 1 1058.82 2009-02-18T00:49:00 3 60 288190207 35 35 1 264.71 2009-02-18T00:50:00 4 -999 288190267 35 35 0 0.0
Note that the state file contains five entries (rows). The first entry gives the initial command state of the instrument and is assigned a state index of 0. The start time (SCET_UTC and SCLK ticks in seconds) for this state is given along with the amount of time in seconds (DELTA_SCLK) that GRaND was in this state. So, for approximately 19800s, the science data accumulation time (TELREADOUT) was set to 70s and the cadence of the state of health telemetery (TELSOH) was 35s. The instrument mode was 1 (normal). So, science data records were being written every 70s. The high voltage setting for the +Z phoswich (HVPS1_SET) was 1058.82V.
The first state is followed by STATE_INDEX 1, where TELREADOUT was set to 2000s. This is done prior to additional commanding to avoid dropped commands as discussed in the Data Processing Document and Prettyman et al. (2011). In following state (STATE_INDEX=2), TELREADOUT has been set to 35s in order to provide a high sample rate as GRaND approached Mars. Note that there is no difference between the SCLK or SCET_UTC times for STATE_INDEX 1 and 2. This is because the command state data are in the SOH telemetry and the SOH time is updated by a command from the spacecraft which is sent every 60s. The amount of time between the commands that set TELREADOUT in STATE_INDEX 1 and 2 was less than 60s. The instrument remains in STATE_INDEX 2 for approximately 8460s. This period of time includes Mars closest approach.
At 2009-02-18T00:49:00, the command state changes again. In this case, HVPS1_SET dropped to 264.71V, corresponding to the ramp down of HV as GRaND was gracefully powered off when the spacecraft entered into safe mode. In the last state (STATE_INDEX=4), GRaND is in standby mode (MODE=0) and the HVPS1_SET is 0. Because it is generally not possible to know how long GRaND was in the last state (e.g., the state may not change between downlinks), the last entry for DELTA_SLCK was assigned -999 (MISSING_CONSTANT).
It is important to understand that because commands can be sent at a cadence higher than TELSOH (typically 35s), the state file is not a complete record of commanding; however, the state file does provide a convenient way to identify long periods of time during which GRaND acquired science data (e.g., STATE_INDEX 0 and 2 above). Additional columns not shown in the example give coincidence window parameters needed to interpret the data.
The RDR data are derived from the EDR files, which cover arbitrary and irregular time periods, generally determined by the pattern of downlinks from the spacecraft. The RDR are typically evaluated for a single instrument state found in the EDR files, generally corresponding to the instrument fully configured for science data acquisition. Unless otherwise indicated, the value of TELREADOUT is the same for all records extracted from a particular EDR file. The EDR science records need not be contiguous; however, time-windows containing gaps are not included in the RDR. Generally, science data records with elevated counting rates associated with solar energetic particle (SEP) events will be excluded from the RDR; however, throughout MGA, solar activity was minimal and no records were lost.
The RDR files are contained in a single directory. The name of the directory includes the type of time series [CMA or DTS, see Table 5, the Data Processing Document, and Prettyman et al. (2011)for a description of how time series data are represented]:
The top level directory name contains the SCET UTC dates for the first and last science data records (Y1M1D1 and Y2M2D2, respectively), and the creation date (YCMCDC) for the archive. For example, for GRD-L1B-090217-090218_090517, the first science data record was acquired on 17-Feb-2009. The last science data record was acquired on 18-Feb-2009. The archive was created by the processing code on 17-May-2009.
The data files and formats are the same for both types of time series. All counting rates are reported as counts per second. Histograms have units of counts/second/channel. The processing parameters, including the window width and the value of TELREADOUT are given in the label files. The following files are included (note that 'TSI' is either 'CMA' or 'DTS', depending on the type of time series):
The RDR for Vesta encounter deviates from the aforementioned structure in the following ways. All RDR data files are included at the top level of the DATA directory. A single file contains ephemeris, pointing, and geometry data along with selected measurements for each and every science data record acquired during Vesta encounter:
GRD-L1B-110503-120809_YCMCDC-EPG.TAB,
The BGO time-series of corrected gamma ray pulse height spectra are divided across Vesta encounter mission phases. See the Dawn mission catalog for a description of mission phases. For example, for the sub-phase Vesta Science LAMO (VSL), the corresponding BGO data file is
GRD-L1B-Y0M0D0-Y1M1D1_YCMCDC-VSL-BGOC.TAB,
where Y0M0D0 and Y1M1D1 are respectively the dates on which the first and last records of GRaND data were acquired during VSL. Neither the EPG nor BGO RDR data files contain decimated or time-averaged data. Therefore, the aforementioned TSI designation is not included in the file names.
The label provides descriptive information about the associated data file. PDS labels for all GRaND data have the same structure. Most of the keywords belong to one of the following groups:
1. File information 2. Time information 3. Data production information 4. Mission description 5. Instrument description 6. Geometry information 7. Dataset and product information 8. Data object (table) description 9. Data object structure description
Keywords belonging to the above groups are listed in the following sections, while the last section describes the other keywords. An example of an actual label is provided in Appendix A; more details on the possible values of each keyword and the origin of each value can be found in Appendix B. In the following sections, the values are given for the file 'GRD-L1A- 090216090217_090703-BGO.LBL', which is located on the L1A Mars flyby volume (DWNGRD_1A). Values for other files will differ.
PDS data product labels contain data element information that describes the physical structure of a data product file. The PDS file characteristic data elements are:
PDS_VERSION_ID = PDS3
The keywords listed in this group describe the format of the data.
RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 6176 FILE_RECORDS = 819 TABLE = 'GRD-L1A-090216-090217_110225-BGO.TAB' PRODUCER_FULL_NAME = "T. H. PRETTYMAN" PRODUCER_INSTITUTION_NAME = "PLANETARY SCIENCE INSTITUTE" PRODUCT_CREATION_TIME = 2011-02-25T00:46:38
RECORD_TYPE is the record format of the file; all GRaND data files will be using a fixed-length record format. RECORD_BYTES is the number of bytes in a record. FILE_RECORDS is the length of the data file in records number. PRODUCT_CREATION_TIME contains the date and time in which the PDS file was created. ^TABLE is a pointer to the data file.
The keywords listed in this group give the timing information.
START_TIME = 2009-02-16T15:16 STOP_TIME = 2009-02-17T21:22 SPACECRAFT_CLOCK_START_COUNT = "0288069434.000" SPACECRAFT_CLOCK_STOP_COUNT = "0288177826.000"
START_TIME and STOP_TIME give the corrected UTC spacecraft time of start and stop of observation; the second keyword must always be present even if the stop time is unknown or unavailable.
SPACECRAFT_CLOCK_START_COUNT and SPACECRAFT_CLOCK_STOP_COUNT store the spacecraft time in its original form on the TM packet header.
The keywords listed in this group give data production software information.
SOFTWARE_NAME = "GRD_L1A_PIPELINE" SOFTWARE_VERSION_ID = "Version 1.0"
SOFTWARE_NAME, and SOFTWARE_VERSION_ID identify the software used to write the labels and format the data (i.e., the EGSE software for calibration and flight raw data, processing software for derived products).
The keywords listed in this group describe mission, mission phase, instrument type and so on.
MISSION_NAME = "DAWN MISSION TO VESTA AND CERES" MISSION_ID = "DAWN" INSTRUMENT_HOST_NAME = "DAWN" INSTRUMENT_HOST_ID = "DAWN"
The keywords listed in this group describe the instrument.
INSTRUMENT_ID = "GRAND" INSTRUMENT_NAME = "GAMMA-RAY AND NEUTRON DETECTOR"
The keywords listed in this group give the geometry information.
MISSION_PHASE_NAME = "MARS GRAVITY ASSIST (MGA)" TARGET_NAME = "MARS" TARGET_TYPE = "PLANET" ORBIT_NUMBER =
DATA_SET_ID = "DAWN-M-GRAND-2-EDR-MARS-COUNTS-V1.0" DATA_SET_NAME = "DAWN GRAND RAW (EDR) MARS FLYBY COUNTS V1.0" PRODUCT_ID = "GRD-L1A-090216-090217_110225-BGO" PRODUCT_TYPE = "DATA" PRODUCT_VERSION_ID = "1.0"
PDS_VERSION_ID is the version number of the PDS standard document that is valid when a data product label is created.
The keyword PRODUCT_ID gives the actual name of the file containing the data.
The PDS requires a separate data object definition within the product label for the TABLE object, to describe its structure and associated attributes. The object definition for a TABLE is in the form:
OBJECT = TABLE ROWS = 819 ROW_BYTES = 6176 INTERCHANGE_FORMAT = ASCII COLUMNS = 1026 ^STRUCTURE = "GRD_L1A-BGO.FMT" DESCRIPTION = END_OBJECT = TABLE
ROWS, ROW_BYTES, and COLUMNS are the number of rows, and the fixed number of bytes per row, and columns (respectively) in the table. INTERCHANGE_FORMAT is the coding used in the archive file ('ASCII' or 'BINARY'). ^STRUCTURE is a pointer to an external file which contains record structure information. DESCRIPTION is a text description of the file (the value has been omitted from list of sample values above).
OBJECT = COLUMN NAME = "SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = END_OBJECT = COLUMN
DATA_TYPE describes the alphanumeric format of the column. UNIT is the SI unit (singular) of the column value. START_BYTE and BYTES give the location (from the beginning of the record), and width of the column. FORMAT is the FORTRAN format specification of the column.
An example label for level 1A flight data is shown below. In the following example the non constant values, when present, must be meant only as examples. All the keywords that are not meaningful for a given phase of the mission will have a value "N/A".
PDS_VERSION_ID = PDS3 /* label standards identifiers PDS Version 3.8 */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 6176 FILE_RECORDS = 1199 MD5_CHECKSUM = "4dab8a01d725a83b004dc4db90e21dbc" ^TABLE = "GRD-L1A-071018-071019_110225-BGO.TAB" PRODUCER_FULL_NAME = "T. H. PRETTYMAN" PRODUCER_INSTITUTION_NAME = "PLANETARY SCIENCE INSTITUTE" PRODUCT_CREATION_TIME = 2011-02-25T03:12:22 PRODUCT_ID = "GRD-L1A-071018-071019_110225-BGO" PRODUCT_TYPE = "DATA" PRODUCT_VERSION_ID = "1.0" START_TIME = 2007-10-18T01:48 STOP_TIME = 2007-10-19T01:06 SPACECRAFT_CLOCK_START_COUNT = "0245944149.000" SPACECRAFT_CLOCK_STOP_COUNT = "0246028079.000" SOFTWARE_NAME = "GRD_L1A_PIPELINE" SOFTWARE_VERSION_ID = "Version 1.0" MISSION_NAME = "DAWN MISSION TO VESTA AND CERES" MISSION_ID = "DAWN" INSTRUMENT_HOST_NAME = "DAWN" INSTRUMENT_HOST_ID = "DAWN" INSTRUMENT_ID = "GRAND" INSTRUMENT_NAME = "GAMMA-RAY AND NEUTRON DETECTOR" MISSION_PHASE_NAME = "INITIAL CHECKOUT (ICO)" TARGET_NAME = "CALIBRATION" TARGET_TYPE = "CALIBRATION" DATA_SET_ID = "DAWN-X-GRAND-2-EDR-CRUISE-COUNTS-V1.0" DATA_SET_NAME = "DAWN GRAND RAW (EDR) CRUISE CHECKOUT/BACKGROUND COUNTS V1.0" SPICE_FILE_NAME = ("naif0009.tls", "DAWN_203_SCLKSCET.00008.tsc") OBJECT = TABLE ROWS = 1199 ROW_BYTES = 6176 INTERCHANGE_FORMAT = ASCII COLUMNS = 3 ^STRUCTURE = "GRD_L1A-BGO.FMT" DESCRIPTION = " This time series contains GRaND EDR (level1a) science data (APID 190) extracted from raw telmetry packets via a data pipeline. The level1a data were derived from the following raw data file: grd_190pb_072920100_0100_0.dat Each row contains level1a science data that has been tagged with the SCET_UTC time and SCLK tics for the first packet of the corresponding science data record. The process of converting raw science data records to level1a records involves separating the science data from the packet headers, decoding and unscrambling the event mode data, and decompressing the histograms. This file contains a time series of BGO histograms. " END_OBJECT = TABLE END
This section contains copies of all of the format files for the GRaND level 1A (EDR) data products. Non-constant values, when present, are meant only as examples. All keywords that are not meaningful for a given column object will have a value "N/A".
The instrument state file contains the instrument settings, including the mode, power supply states, high voltage settings, the data accumulation interval, and coincidence windows. The format file for the instrument state file is named 'GRD_L1A-STATE.FMT'.
OBJECT = COLUMN NAME = "SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the packet's SCLK value. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "STATE_INDEX" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 20 BYTES = 5 FORMAT = "I5" VALID_MAXIMUM = 9999 DESCRIPTION = " The state index is a counter that starts at 0 and increments every time the state changes. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "DELTA_SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 25 BYTES = 8 FORMAT = "I8" VALID_MAXIMUM = 9999 MISSING_CONSTANT = -999 DESCRIPTION = " The number of SCLK ticks (seconds) that the instrument was in the state. When only one state is present, then the duration is unknown. The last state for a file with multiple states has an unknown duration. These states are assigned the MISSING_CONSTANT. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 33 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count at the start of the SOH interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TELREADOUT" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 44 BYTES = 6 FORMAT = "I6" VALID_MINIMUM = 15 VALID_MAXIMUM = 2000 DESCRIPTION = " Measurement interval for the science data. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "TELSOH" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 50 BYTES = 6 FORMAT = "I6" VALID_MINIMUM = 2 VALID_MAXIMUM = 2000 DESCRIPTION = " Measurement interval for the state-of-health readout. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "MODE" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 56 BYTES = 2 FORMAT = "I2" DESCRIPTION = " Instrument mode (0=Standby, 1=Normal, 2=Anneal) " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS1_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 58 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 1, which supplies the photomultiplier tube for the +Z phoswich. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS1" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 67 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS1 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS2_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 69 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 2, which supplies the photomultiplier tube for the -Z phoswich. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS2" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 78 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS2 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS3_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 80 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 3, which supplies the photomultiplier tube for the -Y boron-loaded plastic scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS3" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 89 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS3 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS4_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 91 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 4, which supplies the photomultiplier tube for the +Y boron-loaded plastic scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS4" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 100 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS4 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS5_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 102 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 5, which supplies the photomultiplier tube for the BGO scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS5" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 111 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS5 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS6_SET" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 113 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Set point for high voltage power supply (HVPS) 6, which provides the bulk bias for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "HVPS6" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 122 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, then HVPS6 is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PM5_LVPS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 124 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, the analog +/-5V low voltage power supply is enabled. The supply provides power for analog and digital components, including the scintillator pulse processing electronics and internal sensors (temperature and voltage). " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "P12_LVPS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 126 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, the +12V low power supply is enabled, which supplies the high voltage power supplies (if MODE=1) and the resistive heaters (if MODE=2) used to anneal the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CZT_PM5_LVPS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 128 BYTES = 2 FORMAT = "I2" VALID_MAXIMUM = 1 DESCRIPTION = " If 1, the +/-5V supply for the CZT analog pulse processing circuits is enabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CZT_ENABLES" DATA_TYPE = CHARACTER UNIT = "N/A" START_BYTE = 130 BYTES = 17 FORMAT = "A17" DESCRIPTION = " Bit pattern indicating the state (1=disabled, 0=enabled) of each of the 16 CZT sensors, represented as a character string. For readability, the first character is blank. The remaining characters represent bits, read right to left, which give the state of the 16 sensors in order from 0-15. For example, the pattern 1111111111111110 indicates that all of the CZT sensors are disabled except for sensor 0. The pattern 0010000000000010 indicates that two of the sensors (1 and 13) are disabled. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NEMG_TOT_EVTS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 147 BYTES = 5 FORMAT = "I5" VALID_MAXIMUM = 6676 DESCRIPTION = " Total number of gamma ray events recorded in the science data file. Note that NEMG_TOT_EVTS + NEMN_TOT_EVTS is always less than or equal to 6676. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NEMG_CZT_EVTS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 152 BYTES = 5 FORMAT = "I5" VALID_MAXIMUM = 6676 DESCRIPTION = " The number of CZT single interaction (CAT10) events recorded in the event buffer. This value is always less than NEMG_TOT_EVTS. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NEMN_TOT_EVTS" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 157 BYTES = 5 FORMAT = "I5" VALID_MAXIMUM = 6676 DESCRIPTION = " Total number of neutron events recorded in the science data file. Note that NEMG_TOT_EVTS + NEMN_TOT_EVTS is always less than or equal to 6676. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BGO_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 162 BYTES = 5 FORMAT = "I5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = " Lower channel (output of the BGO ADC)for the CAT2 coincidence window for the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BGO_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 167 BYTES = 5 FORMAT = "I5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 coincidence window for the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BGO_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 172 BYTES = 5 FORMAT = "I5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = " Lower channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for the BGO spectrum. Note that H_BGO_ROI - L_BGO_ROI = 64. The window gives range of channels for the CAT2 BGO pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BGO_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 177 BYTES = 5 FORMAT = "I5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for the BGO spectrum. Note that H_BGO_ROI - L_BGO_ROI = 64. The window gives range of channels for the CAT2 BGO pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_MY_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 182 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 coincidence window for the -Y BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_MY_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 186 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BLP ADC)for the CAT2 coincidence window for the -Y BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_MY_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 190 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 region of interest (ROI) for BLP -Y. Note that H_BLP_MY_ROI - L_BLP_MY_ROI = 64. The window gives the range of channels for the CAT2 BLP -Y pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_MY_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 194 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for BLP -Y. Note that H_BLP_MY_ROI - L_BLP_MY_ROI = 64. The window gives range of channels for the CAT2 BLP -Y pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_PY_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 198 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 coincidence window for the +Y BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_PY_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 202 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BLP ADC)for the CAT2 coincidence window for the +Y BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_PY_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 206 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 region of interest (ROI) for BLP +Y. Note that H_BLP_PY_ROI - L_BLP_PY_ROI = 64. The window gives the range of channels for the CAT2 BLP +Y pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_PY_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 210 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for BLP +Y. Note that H_BLP_PY_ROI - L_BLP_PY_ROI = 64. The window gives range of channels for the CAT2 BLP +Y pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_MZ_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 214 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 coincidence window for the -Z BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_MZ_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 218 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BLP ADC)for the CAT2 coincidence window for the -Z BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_MZ_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 222 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 region of interest (ROI) for BLP -Z. Note that H_BLP_MZ_ROI - L_BLP_MZ_ROI = 64. The window gives the range of channels for the CAT2 BLP -Z pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_MZ_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 226 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for BLP -Z. Note that H_BLP_MZ_ROI - L_BLP_MZ_ROI = 64. The window gives range of channels for the CAT2 BLP -Z pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_PZ_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 230 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 coincidence window for the +Z BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_PZ_CW" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 234 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BLP ADC)for the CAT2 coincidence window for the +Z BLP sensor. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "L_BLP_PZ_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 238 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Lower channel (output of the BLP ADC)for the CAT2 region of interest (ROI) for BLP +Z. Note that H_BLP_PZ_ROI - L_BLP_PZ_ROI = 64. The window gives the range of channels for the CAT2 BLP +Z pulse height spectra. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "H_BLP_PZ_ROI" DATA_TYPE = ASCII_INTEGER UNIT = "N/A" START_BYTE = 242 BYTES = 4 FORMAT = "I4" VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Upper channel (output of the BGO ADC)for the CAT2 region of interest (ROI) for BLP +Z. Note that H_BLP_PZ_ROI - L_BLP_PZ_ROI = 64. The window gives range of channels for the CAT2 BLP +Z pulse height spectra. " END_OBJECT = COLUMN
This file contains a time-ordered list of temperature and voltage readings averaged over each state-of-health accumulation interval (TELSOH), converted to physical units. The format file for the instrument readings file is named "GRD_L1A-READINGS.FMT".
OBJECT = COLUMN NAME = "SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the packet's SCLK value. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count at the start of the SOH interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS1" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 31 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 1, which supplies the photomultiplier tube for the +Z phoswich. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS2" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 40 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 2, which supplies the photomultiplier tube for the -Z phoswich. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS3" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 49 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 3, which supplies the photomultiplier tube for the -Y boron-loaded plastic scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS4" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 58 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 4, which supplies the photomultiplier tube for the +Y boron-loaded plastic scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS5" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 67 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 5, which supplies the photomultiplier tube for the BGO scintillator. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_HVPS6" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 76 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for high voltage power supply (HVPS) 6, which provides the bulk bias for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="V_CZT70" DATA_TYPE = ASCII_REAL UNIT = "VOLTS" START_BYTE = 85 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Reading for the differential bias supply for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_CZT1" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 94 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor 1 for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_CZT2" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 103 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor 2 for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_CZT3" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 112 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor 3 for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_CZT4" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 121 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor 4 for the CZT array. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_LVPS" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 130 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor for the low voltage power supply. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_HVPS" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 139 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor for the high voltage power supply. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_BGO" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 148 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor for the BGO crystal (representative of the bulk scintillator temperature). " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_PMT" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 157 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor for the photomultiplier tube assembly. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="T_INTERFACE" DATA_TYPE = ASCII_REAL UNIT = "CELSIUS" START_BYTE = 166 BYTES = 9 FORMAT = "F9.2" DESCRIPTION = " Temperature sensor for the interface. " END_OBJECT = COLUMN
This file contains a time-ordered list of the scaler data recorded in either the science, or state-ofhealth telemetry. The format file is named 'GRD_L1A-SCI-SCALER.FMT'.
OBJECT = COLUMN NAME = "SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) at the end of the science accumlation interval, determined from the packet's SCLK value. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count at the end of the science accumulation interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PSC_SCI" DATA_TYPE = "N/A" START_BYTE = 31 BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " Packet sequence counter (PSC_SCI) from the science telemetry. The PSC for the first packet of each science data record is provided. The counter rolls over at 65535. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SCALER_SCI" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 37 BYTES = 138 ITEMS = 23 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " Scaler data from the APID190 science data file (23 scalers defined in the Level1a dataset catalog file). " END_OBJECT = COLUMN
This file contains a time-ordered list of the scaler data recorded in the state-of-health telemetry. The format file is named "GRD_L1A-SOH-SCALER.FMT".
OBJECT = COLUMN NAME = "SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the packet's SCLK value. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " The last spacecraft clock count received by GRaND from the spacecraft. A timestamp command is sent by the spacecraft every 60s. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "PSC_SOH" DATA_TYPE = "N/A" START_BYTE = 31 BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " Packet sequence counter (PSC_SOH) from the state-of-health telemetry. The counter rolls over at 65535. " END_OBJECT = COLUMN OBJECT = COLUMN NAME = "SCALER_SOH" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 37 BYTES = 138 ITEMS = 23 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " Scaler data from the APID191 state-of-health telemetry file (23 scalers defined in the Level1a dataset catalog file). " END_OBJECT = COLUMN
This file contains a time-ordered list of pulse height spectra (1024 channels with units of uncorrected counts/channel) acquired by the BGO sensor. This format file is named "GRD_L1A-BGO.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BGO_HIST" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 6144 ITEMS = 1024 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BGO pulse height histogram (1024 channels). " END_OBJECT = COLUMN
This file contains gamma ray event data as a binary time series. This format file is named "GRD_L1A-GAMMA_EVENTS.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 20 DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc, including a trailing blank. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "SECONDS" START_BYTE = 21 BYTES = 4 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCALER_SCI" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "COUNTS" START_BYTE = 25 BYTES = 92 ITEMS = 23 ITEM_BYTES = 4 DESCRIPTION = " Scaler data recorded in the science record (23 scalers) described in the dataset catalog. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="ID_CZT" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 117 BYTES = 3876 ITEMS = 3876 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 15 DESCRIPTION = " Vector of 3876 gamma events: CZT sensor indices (0-15) for each event. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="CH_CZT" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 3993 BYTES = 7752 ITEMS = 3876 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 2047 DESCRIPTION = " Vector of 3876 gamma events: CZT pulse height (0-2047) for each event. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="CH_BGO" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 11745 BYTES = 7752 ITEMS = 3876 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 511 DESCRIPTION = " Vector of 3876 gamma events: BGO pulse height (0-511) for each event. " END_OBJECT = COLUMN
These files contain time ordered lists of the 256-channel CAT1 pulse height spectra for the -Z phoswich. This format file is named "GRD_L1A-PHOS_MZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="PHOS_MZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 1536 ITEMS = 256 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " -Z phoswich pulse height histogram (256 channels). " END_OBJECT = COLUMN
These files contain time ordered lists of the 256-channel CAT1 pulse height spectra for the +Z phoswich. This format file is named "GRD_L1A-PHOS_PZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="PHOS_PZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 1536 ITEMS = 256 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " +Z phoswich pulse height histogram (256 channels). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BGO pulse height spectra for coincidences with the BGO and the -Z BLP sensors. This format file is named "GRD_L1A-BGO2_MZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BGO2_MZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BGO pulse height histogram (64 channels) for coincidence events between the -Z BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BGO pulse height spectra for coincidences with the BGO and the +Z BLP sensors. This format file is named "GRD_L1A-BGO2_PZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BGO2_PZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BGO pulse height histogram (64 channels) for coincidence events between the +Z BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BGO pulse height spectra for coincidences with the BGO and the -Y BLP sensors. This format file is named "GRD_L1A-BGO2_MY.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BGO2_MY" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BGO pulse height histogram (64 channels) for coincidence events between the -Y BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BGO pulse height spectra for coincidences with the BGO and the +Y BLP sensors. This format file is named 'GRD_L1A-BGO2_PY.FMT'.
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BGO2_PY" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BGO pulse height histogram (64 channels) for coincidence events between the +Y BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BLP pulse height spectra for coincidences with the BGO and the -Z BLP sensor. This format file is named "GRD_L1A-BLP2_MZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BLP2_MZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BLP pulse height histogram (64 channels) for coincidence events between the -Z BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BLP pulse height spectra for coincidences with the BGO and the +Z BLP sensor. This format file is named "GRD_L1A-BLP2_PZ.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BLP2_PZ" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BLP pulse height histogram (64 channels) for coincidence events between the +Z BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BLP pulse height spectra for coincidences with the BGO and the -Y BLP sensor. This format file is named "GRD_L1A-BLP2_MY.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BLP2_MY" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BLP pulse height histogram (64 channels) for coincidence events between the -Y BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
These files contain time ordered lists of the 64-channel CAT2 BLP pulse height spectra for coincidences with the BGO and the +Y BLP sensor. This format file is named "GRD_L1A-BLP2_PY.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" VALID_MAXIMUM = 4294967295 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="BLP2_PY" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS" START_BYTE = 31 BYTES = 384 ITEMS = 64 ITEM_BYTES = 6 FORMAT = "I6" VALID_MAXIMUM = 65535 DESCRIPTION = " BLP pulse height histogram (64 channels) for coincidence events between the +Y BLP and BGO scintillators (CAT2). " END_OBJECT = COLUMN
This file contains the neutron event data as a binary time series. This format file is named "GRD_L1A-NEUTRON_EVENTS.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME UNIT = "N/A" START_BYTE = 1 BYTES = 20 DESCRIPTION = " The UTC spacecraft event time (SCET) determined from the SCLK value for the first packet in the science data record. The time format is yyyy-mm-ddThr:mn:sc, including a trailing blank. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCLK" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "SECONDS" START_BYTE = 21 BYTES = 4 DESCRIPTION = " Spacecraft clock count recorded in the first packet of the science data record, indicating the starting time for the collection interval. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="SCALER_SCI" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "COUNTS" START_BYTE = 25 BYTES = 92 ITEMS = 23 ITEM_BYTES = 4 DESCRIPTION = " Scaler data recorded in the science record (23 scalers) described in the dataset catalog. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="ID_FIRST" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 117 BYTES = 2800 ITEMS = 2800 ITEM_BYTES = 1 DESCRIPTION = " Vector of 2800 neutron events: Scintillator index for the first pulse (0=+Z phoswich; 1=-Y BLP; 2=+Y BLP; 3=-Z phoswich). " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="CH_FIRST" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 2917 BYTES = 2800 ITEMS = 2800 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Vector of 2800 neutron events: Height of the first pulse (0-255). " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="ID_SECOND" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 5717 BYTES = 2800 ITEMS = 2800 ITEM_BYTES = 1 DESCRIPTION = " Vector of 2800 neutron events: Scintillator index for the second pulse (0=+Z phoswich; 1=-Y BLP; 2=+Y BLP; 3=-Z phoswich). " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="CH_SECOND" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = "N/A" START_BYTE = 8517 BYTES = 2800 ITEMS = 2800 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Vector of 2800 neutron events: Height of the second pulse (0-255). " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="TTSP" DATA_TYPE = MSB_UNSIGNED_INTEGER UNIT = NANOSECONDS SCALING_FACTOR = 100 START_BYTE = 11317 BYTES = 2800 ITEMS = 2800 ITEM_BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 255 DESCRIPTION = " Vector of 2800 neutron events: Time between the first and second pulse (0-255), with units of 100 nanoseconds/data number. " END_OBJECT = COLUMN
An example label for level 1B flight data is shown below. In the following example the non constant values, when present, must be meant only as examples. All the keywords that are not meaningful for a given phase of the mission will have a value "N/A".
PDS_VERSION_ID = PDS3 /* label standards identifiers PDS Version 3.8 */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 196 FILE_RECORDS = 232 MD5_CHECKSUM = "033a19f16b1234101939b4bf8fb4c158" ^TABLE = "GRD-L1B-090217-090218_110225-CMA-EPM.TAB" PRODUCER_FULL_NAME = "T. H. PRETTYMAN" PRODUCER_INSTITUTION_NAME = "PLANETARY SCIENCE INSTITUTE" PRODUCT_CREATION_TIME = 2011-02-25T06:09:07 PRODUCT_ID = "GRD-L1B-090217-090218_110225-CMA-EPM" PRODUCT_TYPE = "DATA" PRODUCT_VERSION_ID = "1.0" START_TIME = 2009-02-17T22:32:29 STOP_TIME = 2009-02-18T00:46:04 SOFTWARE_NAME = "GRD_L1B_PIPELINE" SOFTWARE_VERSION_ID = "Version 1.0" MISSION_NAME = "DAWN MISSION TO VESTA AND CERES" MISSION_ID = "DAWN" INSTRUMENT_HOST_NAME = "DAWN" INSTRUMENT_HOST_ID = "DAWN" INSTRUMENT_ID = "GRAND" INSTRUMENT_NAME = "GAMMA-RAY AND NEUTRON DETECTOR" MISSION_PHASE_NAME = "MARS GRAVITY ASSIST (MGA)" TARGET_NAME = "MARS" TARGET_TYPE = "PLANET" DATA_SET_ID = "DAWN-M-GRAND-3-RDR-MARS-COUNTS-V1.0" DATA_SET_NAME = "DAWN GRAND CALIBRATED MARS FLYBY COUNTS V1.0" SPICE_FILE_NAME = ("naif0009.tls", "DAWN_203_SCLKSCET.00014.tsc", "dawn_rec_081109-090228_090306_v1.bsp", "dawn_sc_090216_090222.bc", "de421.bsp", "pck00008.tpc", "dawn_grand_v00.ti", "dawn_v08.tf") OBJECT = TABLE ROWS = 232 ROW_BYTES = 196 INTERCHANGE_FORMAT = ASCII COLUMNS = 19 ^STRUCTURE = "GRD_L1B-EPM.FMT" DESCRIPTION = " This time series contains GRaND calibrated (level1b) data. The time series was constructed by averaging corrected counting rates over a moving window using one of two methods: Central Moving Average (CMA) or Decimated Time Series (DTS). The CMA method provides an result for each science data record by averaging over records on either side of the current point as illustrated here: Science records XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ... | 1 | | 2 | | 3 | | 4 | | 5 | .... where each of the time-ordered science records is indicated by an X and the window boundaries are indicated by the vertical bars. The middle of each time series is labeled with an index (1, 2, ...). The DTS method marches the window through the science data records, resulting in a decimated time series as follows: Science records XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX ...| 1 || 2 || 3 || 4 || 5 |... The number of science data records averaged for each point in the time series is given by WINDOW_WIDTH, which is an odd integer. For both methods, all time, ephemeris, and pointing information is determined at the midpoint of the window. The time series parameters for this data set are given here: SERIES_TYPE = 0 Central Moving Average (CMA) WINDOW_WIDTH = 5 TELREADOUT = 35 TRUE_TIME = 175 This file contains time, pointing, and ephemeris data determined using NAIF/SPICE kernels needed for the analysis of data acquired during Mars Gravity Assist (the target was IAU_MARS). The data includes the distance and direction to Mars center; the velocity of the spacecraft relative to Mars rotated into the instrument coordinate system, which is needed to determine the response of the instrument to low-energy neutrons; the sub-spacecraft longitude, latitude, and altitude; the fractional solid angle subtended by Mars at the spacecraft; and an averaged counting rate, which can be used as a proxy for the galactic cosmic ray flux. " END_OBJECT = TABLE END
This section contains copies of all of the format files for the GRaND level 1B (RDR) data products. Non-constant values, when present, are meant only as examples. All keywords that are not meaningful for a given column object will have a value "N/A".
These files contain a time series of ephemeris and pointing data, including the total livetime, the distance and direction to body center, the velocity of the spacecraft rotated into the reference frame of the instrument, the subsatellite position and altitude, and the fractional solid angle subtended by the body at the spacecraft. In addition, the average counting rate for the 'coincidence of three or more sensors' scaler (SCALER_SCI[15]) is provided as an indicator of the interaction rate of galactic cosmic rays. This format file is named "GRD_L1B-EPM.FMT".
OBJECT = COLUMN COLUMN_NUMBER = 1 NAME ="SCET_UTC" DATA_TYPE = TIME START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) at the middle of each time interval in the series. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME ="ET" DATA_TYPE = ASCII_INTEGER UNIT = "SECONDS" START_BYTE = 20 BYTES = 11 FORMAT = "I11" DESCRIPTION = " Epoch time at the middle of each time interval in the series. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME ="SERIES_TYPE" DATA_TYPE = ASCII_INTEGER START_BYTE = 31 BYTES = 2 FORMAT = "I2" VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = " Type of time series: SERIES_TYPE=0 is a Central Moving Average (CMA) SERIES_TYPE=1 is a Decimated Time Series (DTS) " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME ="WINDOW_WIDTH" DATA_TYPE = ASCII_INTEGER START_BYTE = 33 BYTES = 6 FORMAT = "I6" DESCRIPTION = " Number of science data records used to determine average counting rates that comprise the time series. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME ="TRUE_TIME" DATA_TYPE = TIME UNIT = "SECONDS" START_BYTE = 39 BYTES = 11 FORMAT = "I11" DESCRIPTION = " Product of thw WINDOW_WIDTH and the science data record accumulation time (TELREADOUT). Gives the total accumulation time of the records used to determine the average counting rates. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME ="LIVE_TIME" DATA_TYPE = TIME UNIT = "SECONDS" START_BYTE = 50 BYTES = 11 FORMAT = "F11.1" DESCRIPTION = " The total live time for the science data records used to determine the average counting rates. The live time is given by the true time minus the dead time, which is the amount of time the counting system was busy and unable to process interactions with the sensors. Counting rates are determined by dividing the measured counts by the live time. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME ="DISTANCE_MARS_CENTER" DATA_TYPE = ASCII_REAL UNIT = "KM" START_BYTE = 61 BYTES = 11 FORMAT = "F11.1" DESCRIPTION = " Distance from the spacecraft to the center of Mars determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 8 NAME ="DIRECTION_MARS_CENTER_X" DATA_TYPE = ASCII_REAL START_BYTE = 72 BYTES = 11 FORMAT = "F11.5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = " The cosine of the angle of the direction to Mars center relative to the X-axis of the instrument coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 9 NAME ="DIRECTION_MARS_CENTER_Y" DATA_TYPE = ASCII_REAL START_BYTE = 83 BYTES = 11 FORMAT = "F11.5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = " The cosine of the angle of the direction to Mars center relative to the Y-axis of the instrument coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 10 NAME ="DIRECTION_MARS_CENTER_Z" DATA_TYPE = ASCII_REAL START_BYTE = 94 BYTES = 11 FORMAT = "F11.5" VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = " The cosine of the angle of the direction to Mars center relative to the Z-axis of the instrument coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 11 NAME ="VELOCITY_X" DATA_TYPE = ASCII_REAL UNIT = "KM/SECOND" START_BYTE = 105 BYTES = 11 FORMAT = "F11.3" DESCRIPTION = " X-component of the velocity of the spacecraft relative to Mars rotated into the spacecraft coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 12 NAME ="VELOCITY_Y" DATA_TYPE = ASCII_REAL UNIT = "KM/SECOND" START_BYTE = 116 BYTES = 11 FORMAT = "F11.3" DESCRIPTION = " Y-component of the velocity of the spacecraft relative to Mars rotated into the spacecraft coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 13 NAME ="VELOCITY_Z" DATA_TYPE = ASCII_REAL UNIT = "KM/SECOND" START_BYTE = 127 BYTES = 11 FORMAT = "F11.3" DESCRIPTION = " Z-component of the velocity of the spacecraft relative to Mars rotated into the spacecraft coordinate system determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 14 NAME ="LON" DATA_TYPE = ASCII_REAL UNIT = "DEGREES" START_BYTE = 138 BYTES = 7 FORMAT = "F7.1" VALID_MINIMUM = -180 VALID_MAXIMUM = 180 DESCRIPTION = " Longitude of the sub-spacecraft point. East longitude convention is used. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 15 NAME ="LAT" DATA_TYPE = ASCII_REAL UNIT = "DEGREES" START_BYTE = 145 BYTES = 6 FORMAT = "F6.1" VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = " Latitude of the sub-spacecraft point. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 16 NAME ="ALTITUDE" DATA_TYPE = ASCII_REAL UNIT = "KM" START_BYTE = 151 BYTES = 11 FORMAT = "F11.1" DESCRIPTION = " Altitude of the spacecraft determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 17 NAME ="FRACTIONAL_SOLID_ANGLE" DATA_TYPE = ASCII_REAL START_BYTE = 162 BYTES = 11 FORMAT = "F11.4" VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = " Fractional solid angle subtended by Mars at the spacecraft determined at the middle of the time interval. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 18 NAME ="GCR_MONITOR" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 173 BYTES = 11 FORMAT = "F11.5" DESCRIPTION = " Average counting rate for the 'greater than 3 interactions' scaler, used to monitor the flux of galactic cosmic rays. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 19 NAME ="GCR_MONITOR_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 184 BYTES = 11 FORMAT = "F11.5" DESCRIPTION = " Estimated uncertainty in GCR_MONITOR (1-sigma). " END_OBJECT = COLUMN
These files contain a time series of neutron counting rates determined from CAT1, CAT2, and CAT4 pulse height spectra. This format file is named "GRD_L1B-NCR.FMT".
OBJECT = COLUMN COLUMN_NUMBER = 1 NAME ="SCET_UTC" DATA_TYPE = TIME START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) at the middle of each time interval in the series. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME ="CAT1_PZ_BLP" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 20 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area of the 93 keVeq peak in the CAT1 spectrum from the 10B(n,alpha) reaction for the +Z phoswich. Because the scintillator is shielded by Gd and Li-glass, CAT1_PZ_BLP is due primarily to neutrons in the epithermal energy range (between 0.3 eV and 0.7 MeV). " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME ="CAT1_PZ_BLP_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 30 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_PZ_BLP_SIGMA. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME ="CAT1_PZ_LIG" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 40 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area of the peak in the CAT1 spectrum from the 6Li(n,t) reaction for the +Z phoswich. CAT1_PZ_LIG is sensitive to thermal (<0.3 eV)and epithermal neutrons. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME ="CAT1_PZ_LIG_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 50 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_PZ_LIG. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME ="CAT2_MZ" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 60 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the 478 keV peak from the CAT2 coincidence between the BGO and -Z BLP scintillators. The peak results from the deposition of 93 keVee by the 10B(n,alpha) reaction products in the BLP in coincidence with the deposition of 478 keV in the BGO scintillator. Since the -Z scintillator is shielded by Gd and Li-glass, CAT2_MZ is primarily sensitive to epithermal neutrons (between 0.3 eV and 0.7 MeV). " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME ="CAT2_MZ_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 70 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_MZ. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 8 NAME ="CAT2_MY" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 80 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the 478 keV peak from the CAT2 coincidence between the BGO and -Y BLP scintillators. The peak results from the deposition of 93 keVee by the 10B(n,alpha) reaction products in the BLP in coincidence with the deposition of 478 keV in the BGO scintillator. Since the -Y BLP is unshielded, CAT2_MY is sensitive to thermal and epithermal neutrons. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 9 NAME ="CAT2_MY_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 90 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_MY. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 10 NAME ="CAT2_PY" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 100 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the 478 keV peak from the CAT2 coincidence between the BGO and +Y BLP scintillators. The peak results from the deposition of 93 keVee by the 10B(n,alpha) reaction products in the BLP in coincidence with the deposition of 478 keV in the BGO scintillator. Since the +Y BLP is unshielded, CAT2_PY is sensitive to thermal and epithermal neutrons. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 11 NAME ="CAT2_PY_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 110 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_PY. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 12 NAME ="CAT2_PZ" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 120 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the 478 keV peak from the CAT2 coincidence between the BGO and +Z BLP scintillators. The peak results from the deposition of 93 keVee by the 10B(n,alpha) reaction products in the BLP in coincidence with the deposition of 478 keV in the BGO scintillator. Since the +Z scintillator is shielded by Gd and Li-glass, CAT2_PZ is primarily sensitive to epithermal neutrons (between 0.3 eV and 0.7 MeV). " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 13 NAME ="CAT2_PZ_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 130 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in CAT1_PZ. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 14 NAME ="FAST_MZ" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 140 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Fast neutron counting rate measured by the -Z BLP scintillator, determined from the event buffer and scaler counting data. FAST_MZ is sensitive to neutrons with energies greater than 0.7 MeV. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 15 NAME ="FAST_MZ_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 150 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in FAST_MZ. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 16 NAME ="FAST_MY" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 160 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Fast neutron counting rate measured by the -Y BLP scintillator, determined from the event buffer and scaler counting data. FAST_MY is sensitive to neutrons with energies greater than 0.7 MeV. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 17 NAME ="FAST_MY_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 170 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in FAST_MY. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 18 NAME ="FAST_PY" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 180 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Fast neutron counting rate measured by the +Y BLP scintillator, determined from the event buffer and scaler counting data. FAST_PY is sensitive to neutrons with energies greater than 0.7 MeV. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 19 NAME ="FAST_PY_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 190 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in FAST_PY. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 20 NAME ="FAST_PZ" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 200 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Fast neutron counting rate measured by the +Z BLP scintillator, determined from the event buffer and scaler counting data. FAST_PZ is sensitive to neutrons with energies greater than 0.7 MeV. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 21 NAME ="FAST_PZ_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 210 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in FAST_PZ. " END_OBJECT = COLUMN
These files contain a time series of net areas for selected full energy interaction peaks from the pulse height spectrum acquired by the BGO sensor. Propagated uncertainties (1-sigma) are provided. This format file is named "GRD_L1B-GCR.FMT".
OBJECT = COLUMN COLUMN_NUMBER = 1 NAME ="SCET_UTC" DATA_TYPE = TIME START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) at the middle of each time interval in the series. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME ="BGO_ANNIHILATION" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 20 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the 511 keV gamma ray peak (from positron annihilation) from the spectrum acquired by the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME ="BGO_ANNIHILATION_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 30 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in BGO_ANNIHILATION. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME ="BGO_P22" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 40 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the gamma ray peak identified as the 2.21 MeV gamma ray from neutron nonelastic scattering with Al from the spectrum acquired by the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME ="BGO_P22_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 50 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in BGO_P22. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME ="BGO_P44" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 60 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the gamma ray peak identified as the 4.438 MeV gamma ray from the first excited state of 12C from the spectrum acquired by the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME ="BGO_P44_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 70 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in BGO_P44. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 8 NAME ="BGO_P61" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 80 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the gamma ray peak at identified as the 6.129 MeV gamma ray from neutron nonelastic scattering with O from the spectrum acquired by the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 9 NAME ="BGO_P61_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 90 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in BGO_P61. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 10 NAME ="BGO_FE" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 100 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Net area for the gamma ray peak at 7.6 MeV from neutron capture with Fe from the spectrum acquired by the BGO sensor. " END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 11 NAME ="BGO_FE_SIGMA" DATA_TYPE = ASCII_REAL UNIT = "COUNTS/SECOND" START_BYTE = 110 BYTES = 10 FORMAT = "F10.5" DESCRIPTION = " Estimated uncertainty (1-sigma) in BGO_FE. " END_OBJECT = COLUMN
Contains a time series of BGO 1024-channel pulse height spectra that have been adjusted so that the offset is 0 keV with a slope of 8.9 keV/channel. Note that the method for determining the uncertainty in the counting rates for each channel is provided in the format file. This format file is named "GRD_L1B-BGO.FMT".
OBJECT = COLUMN NAME ="SCET_UTC" DATA_TYPE = TIME START_BYTE = 1 BYTES = 19 FORMAT = "A19" DESCRIPTION = " The UTC spacecraft event time (SCET) at the middle of each time interval in the series. The time format is yyyy-mm-ddThr:mn:sc. " END_OBJECT = COLUMN OBJECT = COLUMN NAME ="GAMMA_SPECTRUM_BGO" DATA_TYPE = ASCII_INTEGER UNIT = "COUNTS/SECOND/CHANNNEL" START_BYTE = 21 BYTES = 11264 ITEMS = 1024 ITEM_BYTES = 11 FORMAT = "F11.6" DESCRIPTION = " Average gamma ray pulse height spectrum measured by the BGO sensor (1024 channels)corrected for ADC differential nonlinearity and with the gain and offset adjusted to 8.9 keV/channel and 0 keV, respectively. The uncertainty (1-sigma) in the counting rate for channel i is given by SIGMA_i = SQRT(GAMMA_SPECTRUM_BGO_i*LIVE_TIME))/LIVE_TIME LIVE_TIME is defined in GRD_L1B-EPM.FMT. " END_OBJECT = COLUMN
PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 359 FILE_RECORDS = 35 ^HEADER = ("INDEX.TAB", 1<BYTES>) ^INDEX_TABLE = ("INDEX.TAB", 360<BYTES>) INSTRUMENT_HOST_ID = "DAWN" OBJECT = HEADER HEADER_TYPE = "TEXT" DESCRIPTION = "This row assigns named to each column." RECORDS = 1 BYTES = 359 END_OBJECT = HEADER OBJECT = INDEX_TABLE INTERCHANGE_FORMAT = ASCII INDEX_TYPE = SINGLE DESCRIPTION = "INDEX.TAB lists all the data files on this volume. It starts on line two because the first row has column headers" ROW_BYTES = 359 ROWS = 34 COLUMNS = 15 OBJECT = COLUMN NAME = DATA_SET_ID DESCRIPTION = "The DATA_SET_ID associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 2 BYTES = 35 END_OBJECT = COLUMN OBJECT = COLUMN NAME = FILE_SPECIFICATION_NAME DESCRIPTION = "The FILE_SPECIFICATION_NAME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 40 BYTES = 91 END_OBJECT = COLUMN OBJECT = COLUMN NAME = PRODUCT_ID DESCRIPTION = "The PRODUCT_ID associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 134 BYTES = 10 END_OBJECT = COLUMN OBJECT = COLUMN NAME = VOLUME_ID DESCRIPTION = "The VOLUME_ID associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 147 BYTES = 10 END_OBJECT = COLUMN OBJECT = COLUMN NAME = PRODUCT_CREATION_TIME DESCRIPTION = "The PRODUCT_CREATION_TIME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = TIME START_BYTE = 159 BYTES = 21 END_OBJECT = COLUMN OBJECT = COLUMN NAME = START_TIME DESCRIPTION = "The START_TIME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = TIME START_BYTE = 181 BYTES = 16 END_OBJECT = COLUMN OBJECT = COLUMN NAME = STOP_TIME DESCRIPTION = "The STOP_TIME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = TIME START_BYTE = 198 BYTES = 16 END_OBJECT = COLUMN OBJECT = COLUMN NAME = MISSION_PHASE_NAME DESCRIPTION = "The MISSION_PHASE_NAME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 216 BYTES = 25 END_OBJECT = COLUMN OBJECT = COLUMN NAME = INSTRUMENT_ID DESCRIPTION = "The INSTRUMENT_ID associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 244 BYTES = 13 END_OBJECT = COLUMN OBJECT = COLUMN NAME = TARGET_TYPE DESCRIPTION = "The TARGET_TYPE associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 260 BYTES = 11 END_OBJECT = COLUMN OBJECT = COLUMN NAME = TARGET_NAME DESCRIPTION = "The TARGET_NAME associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 274 BYTES = 11 END_OBJECT = COLUMN OBJECT = COLUMN NAME = ORBIT_NUMBER DESCRIPTION = "The ORBIT_NUMBER associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 287 BYTES = 12 END_OBJECT = COLUMN OBJECT = COLUMN NAME = INTEGRATION_DURATION DESCRIPTION = "The INTEGRATION_DURATION associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 301 BYTES = 20 END_OBJECT = COLUMN OBJECT = COLUMN NAME = OBSERVATION_ID DESCRIPTION = "The OBSERVATION_ID associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 324 BYTES = 14 END_OBJECT = COLUMN OBJECT = COLUMN NAME = OBSERVATION_TYPE DESCRIPTION = "The OBSERVATION_TYPE associated with the file. Please refer to the PDS Data Dictionary for a full description" DATA_TYPE = CHARACTER START_BYTE = 341 BYTES = 16 END_OBJECT = COLUMN END_OBJECT = INDEX_TABLE END
The following is an example document label. The label provided here is for the GRaND Data Processing document.
PDS_VERSION_ID = PDS3 MISSION_NAME = "DAWN MISSION TO VESTA AND CERES" SPACECRAFT_NAME = "DAWN" INSTRUMENT_NAME = "GAMMA-RAY AND NEUTRON DETECTOR" INSTRUMENT_ID = "GRAND" DATA_SET_ID = {"DAWN-M-GRAND-2-EDR-MARS-COUNTS-V1.0", "DAWN-X-GRAND-2-EDR-CRUISE-COUNTS-V1.0", "DAWN-M-GRAND-3-RDR-CRUISE-COUNTS-V1.0"} PRODUCT_ID = "GRAND_DATA_PROC" PRODUCT_TYPE = "DOCUMENT" RECORD_TYPE = STREAM DESCRIPTION = " PDS Data Processing Gamma Ray and Neutron Detector Thomas H. Prettyman and William C. Feldman Version 2.3, 09-Feb-2010 Data processing for the reduction of gamma ray and neutron spectroscopy data acquired by the NASA Dawn mission's Gamma Ray and Neutron Detector (GRaND) is described." OBJECT = PDF_DOCUMENT DOCUMENT_NAME ="GRaND Data Processing Description V2.3" DOCUMENT_TOPIC_TYPE = "DATA ANALYSIS" INTERCHANGE_FORMAT = BINARY DOCUMENT_FORMAT = "ADOBE PDF" PUBLICATION_DATE = 2010-02-09 FILES = 1 END_OBJECT = PDF_DOCUMENT OBJECT = HTML_DOCUMENT DOCUMENT_NAME ="GRaND Data Processing Description V2.3" DOCUMENT_TOPIC_TYPE = "DATA ANALYSIS" INTERCHANGE_FORMAT = ASCII DOCUMENT_FORMAT = "HTML" PUBLICATION_DATE = 2010-02-09 FILES = 1 END_OBJECT = HTML_DOCUMENT OBJECT = JPG_DOCUMENT DOCUMENT_NAME ="GRaND Data Processing Description V2.3" DOCUMENT_TOPIC_TYPE = "DATA ANALYSIS" INTERCHANGE_FORMAT = BINARY DOCUMENT_FORMAT = "JPG" PUBLICATION_DATE = 2010-02-09 FILES = 36 DESCRIPTION = "These are the JPG images referenced by the HTML version of the data processing document." END_OBJECT = JPG_DOCUMENT ^PDF_DOCUMENT = "GRAND_DATA_PROC.PDF" ^HTML_DOCUMENT = "GRAND_DATA_PROC.HTM" ^JPG_DOCUMENT = { "GRAND_DATA_PROC_IMG_0.JPG", "GRAND_DATA_PROC_IMG_1.JPG", "GRAND_DATA_PROC_IMG_2.JPG", "GRAND_DATA_PROC_IMG_3.JPG", "GRAND_DATA_PROC_IMG_4.JPG", "GRAND_DATA_PROC_IMG_5.JPG", "GRAND_DATA_PROC_IMG_6.JPG", "GRAND_DATA_PROC_IMG_7.JPG", "GRAND_DATA_PROC_IMG_8.JPG", "GRAND_DATA_PROC_IMG_9.JPG", "GRAND_DATA_PROC_IMG_10.JPG", "GRAND_DATA_PROC_IMG_11.JPG", "GRAND_DATA_PROC_IMG_12.JPG", "GRAND_DATA_PROC_IMG_13.JPG", "GRAND_DATA_PROC_IMG_14.JPG", "GRAND_DATA_PROC_IMG_15.JPG", "GRAND_DATA_PROC_IMG_16.JPG", "GRAND_DATA_PROC_IMG_17.JPG", "GRAND_DATA_PROC_IMG_18.JPG", "GRAND_DATA_PROC_IMG_19.JPG", "GRAND_DATA_PROC_IMG_20.JPG", "GRAND_DATA_PROC_IMG_21.JPG", "GRAND_DATA_PROC_IMG_22.JPG", "GRAND_DATA_PROC_IMG_23.JPG", "GRAND_DATA_PROC_IMG_24.JPG", "GRAND_DATA_PROC_IMG_25.JPG", "GRAND_DATA_PROC_IMG_26.JPG", "GRAND_DATA_PROC_IMG_27.JPG", "GRAND_DATA_PROC_IMG_28.JPG", "GRAND_DATA_PROC_IMG_29.JPG", "GRAND_DATA_PROC_IMG_30.JPG", "GRAND_DATA_PROC_IMG_31.JPG", "GRAND_DATA_PROC_IMG_32.JPG", "GRAND_DATA_PROC_IMG_33.JPG", "GRAND_DATA_PROC_IMG_34.JPG", "GRAND_DATA_PROC_IMG_35.JPG" } END
--------------------------------------------------------------------------------------------- Table 15: GRaND Archive Generation Support Staff --------------------------------------------------------------------------------------------- Instrument Team --------------------------------------------------------------------------------------------- Dr. Thomas H. Prettyman Planetary Science Institute 505-690-5128; prettyman@psi.edu GRaND Instrument Lead; Albuquerque, NM 505-221-5939 Geochemistry Lead Dr. Naoyuki Yamashita Planetary Science Institute 505-369-7747 yamashita@psi.edu Dawn/GRaND Associate Albuquerque, NM --------------------------------------------------------------------------------------------- DSC --------------------------------------------------------------------------------------------- Dr. Steven P. Joy UCLA-IGPP 310-825-3506 sjoy@igpp.ucla.edu PPI Operations Manager 405 Hilgard Ave Los Angeles, CA 90095-1567 Mr. Joe Mafi UCLA-IGPP 310-206-6073 jmafi@igpp.ucla.edu PPI Data Engineer 405 Hilgard Ave Los Angeles, CA 90095-1567 --------------------------------------------------------------------------------------------- SBN --------------------------------------------------------------------------------------------- Ms. Carol Neese Planetary Science Institute 520-322-8060 neese@psi.edu 1700 East Ft. Lowell, Ste. 106 Tucson, AZ 85719-2395 Dr. Mark V. Sykes Planetary Science Institute 520-322-8925 sykes@psi.edu 1700 East Ft. Lowell, Ste. 106 Tucson, AZ 85719-2395 ---------------------------------------------------------------------------------------------