PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "2001 MARS ODYSSEY" INSTRUMENT_NAME = "GAMMA RAY SPECTROMETER" TARGET_NAME = MARS OBJECT = TEXT PUBLICATION_DATE = 2006-06-01 NOTE = "Introduction to Odyssey GRS Element Concentration Map Data" END_OBJECT = TEXT END 2001 MARS ODYSSEY GAMMA RAY SPECTROMETER ELEMENT CONCENTRATION MAPS 1. Introduction This archive contains a set of maps of elemental concentrations on the surface of Mars, and the Odyssey Gamma Ray Spectrometer data products from which the maps are derived. The maps include concentrations of chlorine, iron, water, potassium, silicon, thorium, and the ratio of potassium to thorium. Further information about these data can be found in Boynton et al. (2007), Concentration of H, Si, Cl, K, Fe, and Th in the low and mid latitude regions of Mars, Journal of Geophysical Research, in review. 2. Archive Contents Files in this archive are organized into a series of subdirectories below the top-level directory. The archive organization and the contents of each directory are described below. Top-level Directory ------------------- AAREADME.TXT The file you are currently reading. VOLDESC.CAT This text file contains a description of the volume contents as a PDS catalog object. It is a required file on PDS archive volumes. BROWSE Directory ---------------- This directory contains the element concentration maps in the form of JPEG images. The file BROWSE.HTM may be opened in a web browser for easy viewing of the maps. Also included are thumbnail versions of the images and PDS labels for the images. CATALOG Directory ----------------- Files in the CATALOG directory are text files containing documentation about the Odyssey mission and spacecraft, the GRS instrument suite, the elemental concentration data set, personnel associated with the archive, and references. See the file CATINFO.TXT for details. The primary documentation for this archive is the data set description file, DATASET.CAT, in this directory. The file REF.CAT contains references to published literature that are relevant to this archive. DATA Directory -------------- The DATA directory contains two subdirectories, UNSMOOTHED and SMOOTHED. The UNSMOOTHED subdirectory contains raw concentration data in latitude- longitude bins of 2x2, 5x5, and 10x10 degrees. The SMOOTHED subdirectory contains the 5x5 degree data smoothed using a boxcar filter algorithm. All data files in these directories are in the form of ASCII text tables having the file extension ".TAB". Each data file is described by a PDS label in a separate file with the same name but the extension ".LBL". The formats of the data files and labels are described below under File Formats. INDEX Directory --------------- The INDEX directory contains a PDS index file for this archive. An index file is an ASCII table in which each record (or line) in the table contains information about a single data product in archive. See the file INDXINFO.TXT for additional details. 3. Archive Volume Format This archive is designed to be accessed as an online resource as well as written to DVD-ROM or other permanent media. On DVD-ROM it is formatted so that a variety of computer systems (e.g., PC, Macintosh, and Sun) may access the data. Specifically, it is formatted according to the ISO-9660 level 2 Interchange Standard. For further information, refer to the ISO-9660 Standard Document: RF# ISO 9660-1988, April 15, 1988. 4. File Formats The GRS elemental concentration data consist of binned concentration and error values in units of weight percent, given as ASCII text tables with detached PDS labels. The PDS labels describe the contents and format of the tables. In a given table, one row contains data for one latitude-longitude bin. The columns are center latitude of bin, center longitude of bin, concentration, and error, with and without correction factors applied. See the PDS label for more details. Files in this archive with the following extensions are ASCII text files: TXT, CAT, HTM, LBL, TAB. Files with the extension JPG are JPEG images. All ASCII text files are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of each line. This allows the files to be read by the MacOS, DOS, Unix, and VMS operating systems. 5. Whom to Contact for Information For questions concerning this archive, contact: PDS Geosciences Node Washington University 1 Brookings Drive, Campus Box 1169 St. Louis, MO 63130 314-935-9295 or 314-935-5493 Web Site: http://pds-geosciences.wustl.edu/ E-mail: geosci@wunder.wustl.edu For general information related to the PDS, contact: Planetary Data System, PDS Operator M/S 202-101 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109-8099 (818) 354-4321 WWW Site: http://pds.nasa.gov/ E-mail: pds_operator@jpl.nasa.gov 6. Cognizant Persons This archive volume designed and produced at the PDS Geosciences Node, Washington University, St. Louis, Missouri by Susan Slavney and Edward Guinness.