PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM ^TEXT = "AAREADME.TXT" OBJECT = TEXT PUBLICATION_DATE = 2017-09-25 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END Volume DWNCGRD_2 Dawn GRaND High Level (2/3) Ceres Encounter Archive ============================================================================== Brief Disk Description ============================================================================== This volume contains data from the Dawn GRaND high level (DDR/MAPS) Ceres Encounter data sets. The data sets a listed below, along with publicly available papers which describe them. Each data set includes a brief dataset catalog file, which describes the map data, coordinate systems, methods to convert tabulated data to physical units (if available), and any other prerequisites for use of the data. The Dawn Geochemistry team has adopted a common format for PDS high level map products, which are presented as ASCII tables. An International Data Language (IDL) function is included in EXTRAS directory to read and display map data. The format allows for different tesselation schemes (e.g. cylindrical or quasi-equal-area pixels), which are described in the label and catalog files for each data set. The pixel geometry selected depends on the intended use of the maps and quality of the data, among other factors. For example, the hydrogen abundance map is a smoothed data set, presented as a 0.5 deg cylindrical map, which is useful for visual comparisons with other map products (overlays & contours). Details of the data reduction and analysis methodology, including binning and smoothing, can be found in the publications accompanying each of the data sets. A list of avialable data sets and references follows: Water Equivalent Hydrogen (WEH) Map GRD_HYDROGEN_MAP Smoothed Water Equivalent Hydrogen (WEH) Map GRD_SMOOTHED_HYDROGEN_MAP Thermal & Epithermal Neutron Counts Map GRD_TPE_NEUTRON_COUNTS_MAP Iron Concentration Map GRD_IRON_MAP Iron Gamma Counts Map GRD_IRON_GAMMA_COUNTS_MAP Prettyman, T.H., N. Yamashita, M.J. Toplis, H.Y. McSween, N. Schorghofer, S. Marchi, W.C. Feldman, J. Castillo-Rogez, O. Forni, D.J. Lawrence, E. Ammannito, B.L. Ehlmann, H.G. Sizemore, S.P. Joy, C.A. Polanskey, M.D. Rayman, C.A. Raymond, C.T. Russell (2017), Extensive water ice within Ceres' aqueously altered regolith: Evidence from nuclear spectroscopy, Science 355 (6320), 55-59, doi: 10.1126/science.aah6765" Russell, C.T., C.A. Raymond, E. Ammannito, D.L. Buczkowski, M.C. De Sanctis, H. Hiesinger, R. Jaumann, A.S. Konopliv, H.Y. McSween, A. Nathues, R.S. Park, C.M. Pieters, T.H. Prettyman, T.B. McCord, L.A. McFadden, S. Mottola, M.T. Zuber, S.P. Joy, C. Polanskey, M. D. Rayman, J.C. Castillo-Rogez, P.J. Chi, J.P. Combe, A. Ermakov, R.R. Fu, M. Hoffmann, Y.D. Jia, S.D. King, D.J. Lawrence, J.-Y. Li, S. Marchi, F. Preusker, T. Roatsch, O. Ruesch, P. Schenk, M.N. Villarreal, N. Yamashita (2016), Dawn arrives at Ceres: Exploration of a small, volatile-rich world, Science 353 (6303), 1008-1010, doi: 10.1126/science.aaf4219" These map data sets have been generated from the GRaND L-1B data taken during the Ceres Science Low Altitude Mapping Orbit phase (CSL) of the Dawn mission. The Dawn GRaND Ceres L-1B are archived in PDS on volume DWNCGRD_1B in the DAWN-A-GRAND-3-RDR-CRUISE-COUNTS-V1.0 data set . NOTE: Reading the Science Plan (DOCUMENTS/SCIENCE_PLAN/DAWN_SCIPLAN_V5_4.PDF) is critical to the understanding of the Ceres observations and science objectives. Other critical documentation in the DOCUMENT directory include the volume SIS and calibration procedure. All data are stored in the 'DATA' branch of the directory tree. In addition to the data files, anciliary information is stored in a separate PDS label (.LBL) file. Users of these data are encouraged to acknowledge both the PDS and the principal investigators of the instruments whose data is used in analysis in all publications. ============================================================================== Volume Set Information ============================================================================== This volume is part of the GRaND high level data volume set. This volume set includes the following volumes: Volume ID Description ------------------------------------------------------------ DWNVGRD_2 Dawn GRaND L2/3 DDR/MAP Vesta Encounter images DWNCGRD_2 Dawn GRaND L2/3 DDR/MAP Ceres Encounter images ============================================================================== Mission Facts ============================================================================== The "Dawn Ceres Science Orbits and Phases" table below provides a list Dawn Ceres Encounter mission phase start dates. ------------------------------------------------------------------------------ Dawn Ceres Science Orbits and Phases ------------------------------------------------------------------------------ start date (DOY) Orbit Phase Name (ID) Orbit Radius ------------------------------------------------------------------------------ 2014-12-26 (360) Approach CERES SCIENCE APPROACH (CSA) 2015-04-24 (114) RC3 CERES SCIENCE RC3 (CSR) ~14,000 km 2015-05-09 (129) Transfer CERES TRANSFER TO SURVEY (CTS) 2015-06-04 (155) Survey CERES SCIENCE SURVEY (CSS) ~4870 km 2015-07-01 (182) Transfer CERES TRANSFER TO HAMO (CTH) 2015-08-17 (229) HAMO CERES SCIENCE HAMO (CSH) ~1950 km 2015-10-23 (296) Transfer CERES TRANSFER TO LAMO (CTL) 2015-12-16 (350) LAMO CERES SCIENCE LAMO (CSL) ~850 km 2016-06-19 (171) XMO1 CERES EXTENDED LAMO (CXL) ~850 km 2016-09-02 (246) Transfer CERES EXTENDED TRANSFER TO JULING (CTJ) 2016-10-10 (284) XMO2 CERES EXTENDED JULING (CXJ) ~1950 km 2016-11-03 (308) Transfer CERES EXTENDED TRANSFER TO GRAND (CTG) 2016-12-13 (348) XMO3 CERES EXTENDED GRAND (CXG) 8.0-9.5e3 km 2017-02-23 (054) Transfer CERES EXTENDED TRANSFER TO OPPOSITION (CTO) 2017-04-28 (118) XMO4 CERES EXTENDED OPPOSITION (CXO) 1.4-5.5e4 km ------------------------------------------------------------------------------ ============================================================================== File Formats ============================================================================== The data files on this volume are in both ASCII. Each data file has an detached ASCII header (PDS label). The PDS label contains information describing spacecraft, target, and data record format. A data set description, instrument description, and other PDS documents are in .CAT files in the /CATALOG directory. Additional documentation is generally located in the DOCUMENT directory. Note for Windows users: 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, do the following. 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. ============================================================================== Errata ============================================================================== Every effort has been made to insure 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. DWNCGRD_2 (root directory) | |- AAREADME.TXT Describes volume contents, and organization (this file) | |- ERRATA.TXT Describes known deficiencies or caveats in the data or | on this volume. | |- VOLDESC.CAT High level description of volume contents. | |- [BROWSE] Contains a PDF plot of the data located in the DATA brach | of this volume. More information on the contents of this | directory is provided in the file /BROWSE/BROWINFO.TXT. | |- [CATALOG] PDS catalog files containing information describing the | data, instrument, instrument personnel, relevant references, | the spacecraft, and mission. More information on the contents | of this directory is provided in the file | /CATALOG/CATINFO.TXT. | |- [DATA] Contains the data files. The data are divided up into | separate subdirectories by data set. | |- [DOCUMENT] Contains documents describing the instrument, and data | acquisition, processing, and usage. More information on the | contents of this directory is provided in the file | /DOCUMENT/DOCINFO.TXT. | |- [EXTRAS] Contains files which facilitate the use of the data on the | disk, but which are not actually required for the use or | understanding of those data. A more detailed description of | the contents of this directory is provided in the file | /EXTRAS/EXTRINFO.TXT. | |- [INDEX] Contains a table of contents for all files located on this | volume, and the volume set to date. A more detailed | description of the contents of this directory is provided in | the file /INDEX/INDXINFO.TXT. ============================================================================ Contacts ============================================================================ This volume was produced for the Planetary Data System (PDS) at the Small Bodies node. The data, and associated metadata were supplied by Dr. Thomas H. Prettyman, of the Planetary Science Institute. The volume was assembled at the Dawn Science Center (DSC), by Joseph N. Mafi. For questions or problems regarding the volume, please contact Dr. Mark Sykes 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. Tom Prettyman of PSI: Email prettyman@psi.edu Telephone 505-690-5128 Mail Planetary Science Institute Albuquerque, NM USA 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.