PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM ^TEXT = "AAREADME.TXT" OBJECT = TEXT PUBLICATION_DATE = 2017-03-24 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END Volume DWNCHVIR_V1B Dawn VIR VIS Calibrated Level-1B (RDR) Ceres Science HAMO Archive ============================================================================== Brief Volume Description ============================================================================== This volume contains the Dawn VIR VIS calibrated level-1B (RDR) cubes from the Dawn Ceres Science HAMO (CSH) encounter phase (2015-08-18 to 2015-10-23). These data have been decompressed, decoded, and formatted into scientifically useful data structures from the original raw telemetry packets. These products, along with their required PDS documentation, form the level-1a data sets (EDRs). The EDRs and then calibrated using the procedure defined in the VIR_CALIBRATION document by using the calibration files found in the CALIB directory. All data files are stored in the 'DATA' branch of the directory tree. The data are organized into subdirectories by phase and activity. DATA subdirectories are named according to the convention: yyyymmdd_nnnnn where: yyyymmdd = phase/activity start date nnnnn = phase/activity name A brief overview of the mission phases and activities (including the start times and names used in the DATA subdirectories is provided in the 'Dawn Science Observations' table below. The data on this volume include both raw data QUBEs and housekeeping data tables. The data QUBEs are named according to the convention: VIR_sss_ll_v_sctime_z, where: 'VIR' = literal sss = sensor ('IR' or 'VIS') ll = processing level ('1A' or '1B') v = clock reset number sctime = the integral portion of the SC_CLK_START_COUNT z = data file version The file extension for the data QUBEs is '.QUB'. The housekeeping data are stored in ASCII tables ('.TAB' file extension). File naming for the housekeeping files is: VIR_sss_ll_v_sctime_HK_z where the 'HK' is literal and the other elements are identical to those in the QUBE files. Both the data QUBE and HK files are accompanied by a PDS label file ('.LBL' file extension), which provides information on the temporal, geometrical, and instrumental conditions under which the data were taken. SPICE kernels are archived by the NAIF Node of the PDS. This volume contains a collection of SPICE metakernel (TM) files in the GEOMETRY directory. These TMs contain a list SPICE kernels that were used in processing the VIR data products, and are referenced in the data product labels. A more detailed description of volume contents and organization is provided in the Dawn VIR Software Interface Specification (SIS) located on this volume at: /DOCUMENT/SIS/ Both PDF-A and HTML (with figures supplied as separate image files) are available. Users of these data are encouraged to acknowledge both the PDS and the principal investigators of the instruments whose data are used in analysis in all publications. Following the loss of the 2nd reaction wheel during Vesta departure, Dawn had to rely on the RCS thrusters, rather than reaction wheels, to maintain pointing. While the Dawn system does not employ true dead-banding, the net result of the thruster firings is to introduce pointing offsets of up to +/- 0.64 degrees in +X and +Y, and rates of up to 0.01 degrees/second (or ~ 0.7 VIR pixels/second). The combination of long VIR integration times with large pointing and pointing rate errors complicates interpreting the data acquired as normal spectral cubes. When Dawn is near to Ceres, the timing of the thruster firings is moderately predicable with the most common attitude near one of the deadband limits. When Dawn is far from its selected target the thruster firing is more random and the impact of not being pointed at Ceres nadir is amplified. This is especially apparent in the VIR cubes since each frame of the cube effectively has its own pointing. During Approach and RC3, Ceres is highly distored in the raw data cubes and care must taken to properly correct the geometry when calibrating and interpretting these data. ============================================================================== Key References ============================================================================== The Dawn Science Plan [RAYMOND2007] is critical to the understanding of the Ceres observations and science objectives. A copy of this document is located in the /DOCUMENT/SCIENCE_PLAN directory of this archive volume. The VIR instrument description paper [DESANCTISETAL2010], contains important information regarding the design and fuction of the VIR instrument, including its calibration and limitations. This document is not not included in the archive, but may be accessed online: De Sanctis, M. C., A. Coradini, E. Ammannito, G. Filacchione M.T. Capria, S. Fonte, G. Magni, A. Barbis, A. Bini, M. Dami, I. Ficai-Veltroni, and G. Preti, VIR Team, The VIR Spectrometer, Space Sci Rev, doi:10.1007/s11214-010-9668-5, 2010. Other critical documentation in the DOCUMENT directory include the volume SIS, calibration procedure, and a description of the VIR internal calibration lamp. ============================================================================== Volume Set Information ============================================================================== This volume is part of the VIR calibrated level-1B RDR data volume set. This volume set includes the following volumes: Volume ID Description -------------------------------------------------------- DWNXVIR_I1B Dawn VIR-IR L1-B RDR cruise data DWNXVIR_V1B Dawn VIR-VIS L1-B RDR cruise data DWNVVIR_I1B Dawn VIR-IR L1-B RDR Vesta data DWNVVIR_V1B Dawn VIR-VIS L1-B RDR Vesta data DWNCAVIR_I1B Dawn VIR-IR L1-B RDR Ceres Approach data DWNCAVIR_V1B Dawn VIR-VIS L1-B RDR Ceres Approach data DWNCSVIR_I1B Dawn VIR-IR L1-B RDR Ceres Survey data DWNCSVIR_V1B Dawn VIR-VIS L1-B RDR Ceres Survey data DWNCHVIR_I1B Dawn VIR-IR L1-B RDR Ceres HAMO data DWNCHVIR_V1B Dawn VIR-VIS L1-B RDR Ceres HAMO data DWNCLVIR_I1B Dawn VIR-IR L1-B RDR Ceres LAMO data DWNCLVIR_V1B Dawn VIR-VIS L1-B RDR Ceres LAMO data ============================================================================== Mission Facts ============================================================================== The 'Dawn Ceres Science Observations' table below provides a list of observations made by the Dawn VIR instrument. It includes the observation start date, the ID of the phase in which it occurred, the activity name, and a brief description. This volume contains Ceres Science HAMO VIS calibrated data. The other calibrated VIR data are contained on the volumes described above. ------------------------------------------------------------------------ Dawn Science Observations ------------------------------------------------------------------------ Start Mission Activity Activity Date Phase Name Description ======================================================================== 14-12-26 CSA APPROACH Ceres Science Approach Phase ------------------------------------------------------------------------ 15-01-13 CSA OPNAV_001 Ride-along cubes to FC OpNav images - 4 obs 15-01-25 CSA OPNAV_002 Ride-along cubes to FC OpNav images - 4 obs 15-02-04 CSA OPNAV_003 Ride-along cubes to FC OpNav images - 5 obs 15-02-12 CSA RC1 Ride-along cubes to FC rotational - 10 obs characterization movie #1 - 8 obs 15-02-19 CSA RC2 Ride-along cubes to FC rotational - 3 obs characterization movie #2 - 3 obs 15-02-25 CSA OPNAV_004 Ride-along cubes to FC OpNav images - 3 obs 15-03-01 CSA OPNAV_005 Ride-along cubes to FC OpNav images - 3 obs 15-04-10 CSA OPNAV_006 Ride-along cubes to FC OpNav images - 3 obs 15-04-15 CSA OPNAV_007 Ride-along cubes to FC OpNav images - 3 obs ======================================================================== 15-04-24 CSR RC3 Ceres Science Rotational Characterization 3 ------------------------------------------------------------------------ 15-04-25 CSR RC3 RC3 Equator Limb 1 (S) high phase - 10 obs 15-04-30 CSR RC3 RC3 Equator Limb 2 (N) high phase - 16 obs 15-05-04 CSR RC3n RC3 North lit side - 16 obs 15-05-05 CSR RC3e RC3 Equator lit side - 16 obs 15-05-07 CSR RC3s RC3 South lit side - 16 obs ------------------------------------------------------------------------ 15-05-09 CTS TRANSFER_ Ceres Transfer to Survey Phase TO_Survey ------------------------------------------------------------------------ 15-05-16 CTS OPNAV_008 Ride-along cubes to FC OpNav images - 7 obs 15-05-22 CTS OPNAV_009 Ride-along cubes to FC OpNav images - 7 obs ------------------------------------------------------------------------ 15-06-04 CSS SURVEY Ceres Science Survey Phase (range ~4850 km) ------------------------------------------------------------------------ 15-06-04 CSS CYCLE1 Survey Cycle (orbit) 1 - 44 obs 15-06-08 CSS CYCLE2 Survey Cycle (orbit) 2 - 49 obs 15-06-11 CSS CYCLE3 Survey Cycle (orbit) 3 - 44 obs 15-06-14 CSS CYCLE4 Data lost to instrument reset, all data lost 15-06-17 CSS CYCLE5 Survey Cycle (orbit) 5 VIS-Only - 51 obs 15-06-21 CSS CYCLE6 Survey Cycle (orbit) 6 - 50 obs 15-06-24 CSS CYCLE7 Survey Cycle (orbit) 7 VIS-Only - 49 obs 15-06-27 CSS CYCLE8 Data lost to instrument reset, all data lost ------------------------------------------------------------------------ 15-07-01 CTH TRANSFER_ Ceres Transfer to HAMO Phase TO_HAMO ------------------------------------------------------------------------ No science observation in this phase ------------------------------------------------------------------------ 15-08-17 CSH HAMO Ceres Science HAMO Phase (avg rng ~1950 km) ------------------------------------------------------------------------ 15-08-17 CSH CYCLE1 12 orb pushbroom nadir imaging - 62 obs 15-08-29 CSH CYCLE2 12 orb pushbroom off-nadir imaging - 71 obs 15-09-09 CSH CYCLE3 12 orb pushbroom off-nadir IR-only - 108 obs 15-09-20 CSH CYCLE4 12 orb pushbroom off-nadir imaging - 85 obs 15-10-01 CSH CYCLE5 12 orb pushbroom near nadir IR-only - 84 obs 15-10-12 CSH CYCLE6 12 orb pushbroom off-nadir imaging - 73 obs ------------------------------------------------------------------------ 15-10-23 CTL TRANSFER_ Ceres Transfer to LAMO Phase TO_LAMO ------------------------------------------------------------------------ No science observation in this phase ============================================================================== File Formats ============================================================================== The data cube files on this volume are binary. The housekeeping (HK) data files are ASCII tables. Both the binary cubes and ASCII HK data have detached PDS labels. The PDS label is an ASCII file containing information describing spacecraft, target, and observation parameters characterizing the associated data file. A data set description, instrument description, and other PDS documents are in .CAT files in the /CATALOG directory. In more recent versions of the Microsoft Windows operating system the .CAT by default is reserved as 'Security Catalog.' The .CAT files contained in this volume are ASCII text files, and can be read by any form of text editor. To make Windows open files with this name extension as text files right click the .CAT file, select with and choose a text editor to open the file. Additional documentation is located in the DOCUMENT directory. ============================================================================== Errata ============================================================================== Every effort has been made to assure that the data and documentation are of the best possible quality. However, mistakes are inevitable. There is a file called ERRATA.TXT found at the root level of this volume which contains a list of known deficiencies or caveats associated with data on this volume at the time this volume was produced. ============================================================================== Volume Contents and Structure ============================================================================== This section describes the volume structure and naming conventions. Below is a tree diagram of the volume, followed by a description of the directory function and key files in each directory. DWNCHVIR_V1B (root directory) | |- AAREADME.TXT Describes volume contents, and organization (this file) | |- ERRATA.TXT Describes known deficiencies or caveats in the data on | this volume. | |- VOLDESC.CAT High level description of volume contents. | |- [CATALOG] PDS catalog files containing information describing the | data, instrument, instrument personnel, relevant references, | the spacecraft, and mission. | |- [DATA] Contains the data. The DATA directory is subdivided into | separate subdirectories by mission phase, and observation | period. | |- [DOCUMENT] Contains documents important to the understanding and use | of the data on this archive volume. | |- [EXTRAS] Contains files which are not an official part of the | archive, and which may not conform with PDS standards, | but which may be of use to data users. | |- [GEOMETRY] Contains VIR SPICE metakernel (TM) files, listing the SPICE | kernels used in generating the data and data label files. | |- [INDEX] Contains a list of all data products on this volume and a a list of geometric parameters associated with each product. ============================================================================ Contacts ============================================================================ This volume was produced for the Planetary Data System (PDS) at the Small Bodies node. The images, and associated metadata were supplied by Dr. Angioletta Coradini at the Istituto Nazionale Di Astrofisica (INAF). The volume was assembled at the Dawn Science Center (DSC), by Joseph N. Mafi. For questions or problems regarding the volume, please contact Dr. Carol Neese at the PDS Small Bodies Node: Email neese@psi.edu Telephone 520-622-6300 Mail Carol Neese Planetary Science Institute 1700 E. Ft. Lowell, Ste. 106 Tuscon, AZ 85719-2395 USA For question regarding the data, please contact Dr. Maria Cristina De Sanctis at INAF: Internet mariacristina.desanctis@iaps.inaf.it Telephone +39 06 499344448 Mail Area di Ricerca di Tor Vergata via del Fosso del Cavaliere, 100 00133 Rome Italy For questions regarding PDS Standards or other archives available from the PDS, please contact PDS Operator at the PDS Engineering Node (at JPL): Email pds_operator@jpl.nasa.gov Telephone 818-354-4321 Mail Planetary Data System, PDS Operator Jet Propulsion Laboratory Mail Stop 202-101 4800 Oak Grove Dr. Pasadena, CA 91109-8099 USA The PDS assumes no legal liability for errors on this disk. All users are encouraged to verify the correctness of the data prior to submitting any publications or other work based on these data. Please report errors on this disk to the Small Bodies Node of the PDS through the ERRATA reporting procedures described above.