PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2011-11-30 INTERCHANGE_FORMAT = ASCII NOTE = "AAREADME file for the Chandrayaan-1 Lunar Orbiter Spacecraft (CH1-ORB) Moon Mineralogy Mapper (M3) Level 2 Reflectance Data Archive" END_OBJECT = TEXT END 1. Introduction This archive contains data acquired by the Chandrayaan-1 Lunar Orbiter Spacecraft (CH1-ORB) Moon Mineralogy Mapper (M3) instrument during the time period of November 2008 through August 2009. Specifically, this contains the the Level 2 reflectance data products that were derived from the the Level 1B reflectance data products located in the PDS data set CH1-ORB-L-M3-4-L1B-RADIANCE-V3.0. 2. Archive Volume Format This section describes the format of this archive volume. 2.1. Volume Format This volume has been formatted according to the ISO-9660 level 2 Interchange Standard for directories and file names as described in Version 3.8 of the PDS Standards Reference. 2.2. File Formats This section describes file formats for the kinds of files contained on this archive volume. All files that comprise this archive are formatted in accordance with Planetary Data System standards version 3.8. 2.2.1. Document File Formats Document files with the .TXT suffix exist in the ROOT, DATA, INDEX, CATALOG, DOCUMENT, LABEL, CALIB, GEOMETRY and EXTRAS directories. They are ASCII files which may have embedded PDS labels. Lines in a .TXT file end with a carriage return character (ASCII 13) and a line feed character (ASCII 10). This allows the files to be readable under various operating systems. Some documents in the DOCUMENT contain formatting and figures that cannot easily be rendered as ASCII text. Therefore each document is given in a PDF Archive format known as PDF/A-1b. PDF (Portable Document Format) is a proprietary format of Adobe Systems Incorporated that is frequently used for distributing documents. Adobe offers free software, Acrobat Reader, for viewing PDF files. Some type of ASCII text versions of these documents will also be included, possibly using HTML or XML, in order to meet the PDS requirement that documents must be archived as ASCII text. 2.2.2. Tabular File Format Tabular files (.TAB suffix) exist in the DATA, INDEX, CALIB directory. Tabular files are ASCII files formatted for direct reading into many database management systems on various computers. Each tabular file is described by a detached PDS label with the same name as the data file it describes but with the extension .LBL. For example, the file INDEX.TAB is accompanied by the detached label file INDEX.LBL in the same directory. 2.2.2.1 INDEX Directory All fields for tabular files in the INDEX directory are separated by commas. (Character fields are padded with spaces to keep quotation marks in the same columns of successive records.) Character fields are left justified, and numeric fields are right justified. The "start byte" listed in the labels indicate the starting position in bytes of each field in a record; the field length "bytes" does not include the commas between fields. The records are of fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. This allows a table to be treated as a fixed length record file on computers that support this file type and as a text file with embedded line delimiters on those that do not. 2.2.2.2 CALIB Directory All fields for tabular files in the CALIB directory are separated by spaces. Numeric fields are right justified. The "start byte" listed in the labels indicate the starting position in bytes of each field in a record. The records are of fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. 2.2.3. PDS Label Format All data files in this archive have PDS labels detached in a separate file. For examples of PDS labels for each type of data product, see the M3 Data Product Software Interface Specifications in the DOCUMENT directory. A PDS label provides descriptive information about the associated file. The PDS label is an object-oriented structure consisting of sets of 'keyword=value' declarations. The object to which the label refers (e.g. IMAGE, TABLE, etc.) is denoted by a statement of the form: ^object = location in which the carat character (^, also called a pointer in this context) indicates where to find the object. In an embedded label, the location is an integer representing the starting record number of the object (the first record in the file is record 1). In a detached label, the location denotes the name of the file containing the object, along with the starting record or byte number, if there is more than one object in the file. For example: ^HEADER = ("F01.IMG",1) ^IMAGE = ("F01.IMG",1025 ) indicates that the IMAGE object begins at byte 1025 of the file F01.IMG, in the same directory as the detached label file.Below is a list of the possible formats for the ^object definition. ^object = n ^object = n ^object = "filename.ext" ^object = ("filename.ext",n) ^object = ("filename.ext",n) where n is the starting record or byte number of the object, counting from the beginning of the file (record 1, byte 1), indicates that the number given is in units of bytes, filename is the up to 28 character, alphanumeric upper-case file name, ext is the 3 character upper-case file extension Lines of text in detached labels end with a carriage return character (ASCII 13) and a line feed character (ASCII 10). This allows the files to be readable under various operating systems. Note that the RECORD_TYPE keyword located in the first few lines of a PDS label will be set to UNDEFINED if the label points to multiple data types. 2.2.4. Catalog File Format Catalog files (suffix .CAT) exist in the ROOT and CATALOG directories. They are text files formatted in an object-oriented structure consisting of sets of 'keyword=value' declarations, so that they are readable by humans and by software. PDS requires these catalog files for tracking and inventory purposes. 2.2.5 Science Data File Formats For more information about the format and content of the data products, see the discussions in the M3 Data Product and Archive Volume Software Interface Specification documents located in the DOCUMENT directory. 3. 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. ERRATA.TXT This text file contains a listing of comments and updates concerning the archive volume. 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. DATA Directory -------------- The DATA directory contains version 1.0 of M3 Level 2 reflectance data products. See the M3 Data Product Software Interface Specification located in the DOCUMENT directory for details. INDEX Directory --------------- The INDEX directory contains PDS index files for this archive. An index file is an ASCII table with each record (or line) in the table containing information about a single data product in the DATA directory of this archive. Files in the INDEX directory are provided to help the user locate products on this archive volume. See the file INDXINFO.TXT for a description of the files in the INDEX directory. DOCUMENT Directory ------------------ The DOCUMENT directory contains documentation to help the user understand and use the archive data. See DOCINFO.TXT for a description of the files in the DOCUMENT directory. CATALOG Directory ----------------- The CATALOG directory contains files that provide an overview of the mission, spacecraft, instruments, and data set. The files in this directory become part of the PDS Catalog to provide background information for the user searching for data. Their format and contents are further specified in the PDS Standards Reference. See the file CATINFO.TXT for a description of the files in the DOCUMENT directory. GEOMETRY Directory ----------------- The Geometry directory contains a single file, GEOMINFO.TXT, which directs the reader to the various SPICE kernels in the M3 Level 1B Radiance archive that contain the data used to derive and interpret the observational geometry. CALIB Directory ------------------ The CALIB directory contains calibration files used to process the Level 2 data products. See the file CALINFO.TXT for a description of the files in the CALIB directory. EXTRAS Directory ------------------ The EXTRAS directory contains value-added elements outside the scope the of the PDS archive requirements 4. Whom to Contact for Information For questions concerning this volume set, contact: PDS Imaging Node Jet Propulsion Laboratory 4800 Oak Grove Dr. Pasadena, CA 91109 USA (818) 354-5677 WWW Site: http://pds-imaging.jpl.nasa.gov E-mail: Susan.K.LaVoie@jpl.nasa.gov 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 USA (818) 354-4321 WWW Site: http://pds.jpl.nasa.gov/ E-mail: pds_operator@jpl.nasa.gov For questions concerning the generation of M3 products, contact: Erick Malaret Applied Coherent Technology Corporation 112 Elden St., Suite K Herndon, VA 20170 USA (703) 742-0294 WWW Site: http://www.actgate.com E-mail: malaret@actgate.com