CCSD3ZF0000100000001NJPL3IF0PDS200000001 = SFDU_LABEL RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 80 SPACECRAFT_NAME = MAGELLAN TARGET_NAME = VENUS OBJECT = TEXT PUBLICATION_DATE = '1992-01-12' NOTE = "MAGELLAN MIDR CD-ROM" END_OBJECT END MAGELLAN MIDR CD-ROM 1. Introduction Overall, the collection of Magellan CD-ROMs contains three data sets. One is the MIDR data set, to which this CD-ROM belongs. Another data set contains the Altimetry and Radiometry Composite Data Record (ARCDR) from MIT. The third data set consists of MIT Altimetric and Radiometric Global Data Records: the Global Topography Data Record (GTDR), Global Emissivity Data Record (GEDR), Global Slope Data Record (GSDR), and Global Reflectivity Data Record (GREDR). This CD-ROM contains 10 Mosaic Image Data Record (MIDR) files and associated documentation. The complete MIDR data set includes F-MIDRs, P-MIDRs, or a mix of C1-MIDRs, C2-MIDRs, and C3-MIDRs. Some of the MIDRs have had cross track smoothing or seam removal procedures applied to them. The volume also contains documentation and index files to support access and use of the mosaics. All data formats are based on the Planetary Data System Data Preparation Workbook ("PDS Data Preparation Workbook, D-7669. May 1991.) and are similar to the formats used in generating the Voyager CD-ROM set ("Voyagers to the Outer Planets", volumes 1-8, Planetary Data System, JPL, 1989). 2. Disk Format The disk has been formatted so that a variety of computer systems (e.g. IBM PC, Macintosh, Sun, VAX) may access the data. Specifically, the disk is formatted according to the ISO 9660 level 1 Interchange Standard, and file attributes are specified by Extended Attribute Records (XARs). For computer software that fully supports XARs, access to the CD-ROM volume will be straightforward; the disk will appear to the user to be identical to a file system of directories, sub- directories, and data files. Some computer systems that do not support XARs will ignore them; others will append the XAR to the beginning of the file. In the latter case the user must ignore the first 512 bytes of the file. For further information, refer to the ISO 9660 Standard Document: RF# ISO 9660-1988, 15 April 1988. 3. File Formats Each F-MIDR and Cx-MIDR are divided into an array of 56 framelets, arranged in seven rows and eight columns. The framelets are numbered in increasing order from left to right, top to bottom. Each framelet is stored in a separate file. A framelet is 1024 lines by 1024 samples, with one byte per sample. The framelet files contain embedded VICAR2 labels and have detached PDS labels. The framelet files and supplementary data files for each MIDR are stored in a separate subdirectory. The MIDRs are all in the sinusoidal equal area map projection, except P-MIDRs which are in the polar stereographic map projection. Additional general information about each product is found in the LABEL directory. The *.LBL files in that directory contain the PDS catalog information for the Magellan Mission, the spacecraft, the radar instrument, and the data sets. Further information on MIDR products can also be obtained from the Magellan Software Interface Specification (SIS) documents IDPS-107, IDPS-109, and IDPS-123. Browse versions of the MIDRs are provided for quick inspection of the images. The browse version of each MIDR is found in the subdirectory for that MIDR. The file name for the browse image is BROWSE.IMG. Each browse image is 896 lines by 1024 samples, and was created by averaging groups of 8x8 pixels in the original 7168x8192 MIDR. Browse images contain embedded VICAR2 labels and have detached PDS labels. The VICAR2 label is from the original 7168X8192 MIDR; therefore, corner points, map projection, pixel size for label items may be inappropriate for the BROWSE.IMG. All document files and detached label files contain 80-byte fixed- length records, with a carriage return character (ASCII 13) in the 79th byte and a line feed character (ASCII 10) in the 80th byte. This allows the files to be read by the MacOS, DOS, Unix, and VMS operating systems. All tabular files are also described by PDS labels, either embedded at the beginning of the file or detached. If detached, the PDS label file has the same name as the data file it describes, with the extension .LBL; for example, the file CONTENTS.TAB is accompanied by the detached label file CONTENTS.LBL in the same directory. The detached labels for MIDRs and GxDRs also contain PDS-defined map projection keywords that provide information needed to extract latitude and longitude values from given line and sample locations. Tabular files are formatted so that they may be read directly into many database management systems on various computers. All fields are separated by commas, and character fields are enclosed in double quotation marks ("). Character fields are left justified, and numeric fields are right justified. The "start byte" and "bytes" values listed in the labels do not include the commas between fields or the quotation marks surrounding character 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 normal text file on other computers. PDS labels are object-oriented. 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 that the object starts at the given location. 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. For example: ^IMAGE_HEADER = ("C1F02.IMG",1) ^IMAGE = ("C1F02.IMG",3) indicates that the IMAGE object begins at record 3 of the file C102.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 = ("[dirlist]filename.ext",n) ^object = ("filename.ext",n) ^object = ("[dirlist]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 upper-case file name ext is the upper-case file extension dirlist is a period-delimited path-list of parent directories, in upper case, that specifies the object file directory (used only when the object is not in the same directory as the label file) The list begins on directory level below the root directory of the CD-ROM. '[dirlist]' may be omitted when the object being described is located either in the same directory as the detached label or in a sub-directory named 'LABEL', located one level below the CD-ROM root directory. 4. CD-ROM Contents The files on this CD-ROM are organized in one top-level directory with several subdirectories. The following table shows the structure and content of these directories. In the table, directory names are enclosed in square brackets ([]), upper-case letters indicate an actual directory or file name, and lower-case letters indicate the general form of a set of directory or file names. FILE CONTENTS Top-level directory | |- AAREADME.TXT The file you are reading. | |- MCUMCOMM.TXT A cumulative listing of comments concerning all | MIDR CD-ROMs published so far. | |- GEO.TAB A table of Venus geologic features. | |- GEO.LBL A PDS detached label that describes GEO.TAB. | |- VOLDESC.SFD A description of the contents of this CD-ROM | volume in a format readable by both humans and | computers. | |- [INDEX] A directory containing index files for searching | | specific MIDR or GxDR products. | | | |- MCUMDIR.TAB A table listing all MIDR and GxDR | | products published so far, including the | | MIDRs on this CD-ROM. | | | |- MCUMDIR.LBL A PDS detached label that describes | | MCUMDIR.TAB. | | | |- CONTENTS.TAB A tabular listing of each MIDR frame on this | | disk, the directory in which it is located, and | | its extent in latitude and longitude. Also | | includes whether MIDR has had seam removal | | procedures applied. | | | |- CONTENTS.LBL A PDS detached label that describes | CONTENTS.TAB. | |- [LABEL] A directory containing catalog information | | describing the major Magellan data products | | that will be submitted to PDS. This | | information can be used to gain a top-level | | understanding of the Magellan Mission, radar | | experiment, processing, and data products. | | | |- CATALOG.LBL PDS high-level experiment-description | | catalog information. | | | |- C1MIDRDS.LBL PDS high-level data set catalog information | | for C1-MIDR. | | | |- C2MIDRDS.LBL PDS high-level data set catalog information | | for C2-MIDR. | | | |- C3MIDRDS.LBL PDS high-level data set catalog information | | for C3-MIDR. | | | |- FBIDRDS.LBL PDS high-level data set catalog information | | for F-BIDR. The F-BIDR is the basic image data | | product. This file provides the information | | on how to extract radar backscatter cross | | section from MIDRs, given the incidence angle | | information from GEOM.TAB and the image data. | | | |- FMIDRDS.LBL PDS high-level data set catalog information | | for F-MIDR. | | | |- xPMIDRDS.LBL PDS high-level data set catalog information | | for P-MIDR, where x is N (north) or S (south). | | | |- DSMAPC1.LBL PDS high-level data set catalog information | | describing C1-MIDR cartographic projections and | | references. This and following map projection | | files allow computation of latitude and | | longitude from image line and sample, using | | either the VICAR2 or PDS label information. | | | |- DSMAPC2.LBL PDS high-level data set catalog information | | describing C2-MIDR cartographic projections and | | references. | | | |- DSMAPC3.LBL PDS high-level data set catalog information | | describing C3-MIDR cartographic projections and | | references. | | | |- DSMAPP.LBL PDS high-level data set catalog information | | describing P-MIDR cartographic projections and | | references. | | | |- DSMAPF.LBL PDS high-level data set catalog information | describing F-MIDR cartographic projections and | references. | |- [x(y)nnzmmm] Directories containing framelets that make up a | single 7168 line by 8192 sample mosaic, where x | is either C (compressed mosaic) or F (full | mosaic), y is either 1, 2 or 3,(C1-MIDR, C2-MIDR, | or C3-MIDR, i.e. once, twice, or thrice compressed | using 3x3 moving averages), or not present, | nn is the middle latitude of the mosaic, z is N | or S (north or south latitude), and mmm is | the middle longitude of the mosaic. Both | middle latitude and longitude have been rounded | off to the nearest integer number. | |- BROWSE.IMG The browse version of the MIDR, 896 lines by | 1024 samples, created by averaging groups of | 8x8 pixels in the original MIDR. | |- BROWSE.LBL A PDS detached label that describes BROWSE.IMG. | |- FRAME.TAB A table describing the range of latitude and | longitude within each image framelet. | |- FRAME.LBL A PDS detached label that describes FRAME.TAB. | |- GEOM.TAB Selected entries from the Magellan | Experimenter's Notebook. The Notebook is | generated from the Magellan Radar Mapping | Sequencing Software and is based on predicted | information. Information is included in | GEOM.TAB on orbit numbers for which | data were acquired and used in the MIDR, | together with information on radar viewing | geometry and image quality. | |- GEOM.LBL A PDS detached label that describes GEOM.TAB. | |- HIST.TAB A binary histogram of pixel values in each | 7168 X 8192 MIDR. | |- HIST.LBL A PDS detached label that describes HIST.TAB. | |- x(y)Fnn.LBL PDS detached labels describing the framelet | files, where x is C (compressed mosaic) or F | (full mosaic), y is 1, 2,or 3 (C1-MIDR, C2-MIDR, | or C3-MIDR), or not present, and nn is the | framelet number (01 through 56). | |- x(y)Fnn.IMG A 1024x1024 image framelet, where x, y, and nn are the same as given above. 5. Recommended CD-ROM Drives and Driver Software Please note that the following list is not complete. However, these drives and driver software were tested and approved by the project. VAX/VMS Drive: Digital Equipment Corporation (DEC) RRD40, RRD42, or RRD50. Driver: DEC VFS CD-ROM driver V4.7 or V5.2 and up. Note: The driver software may be obtained from Jason Hyon at JPL (Files are: JPLPDS::DISK$USER1:[JHYON]VFS*.A). It is necessary to use this driver to access the XARs on the CD-ROM. VAX/Ultrix Drive: DEC RRD40, RRD42, or RRD50. Driver: Supplied with Ultrix 3.1. Note: Use the "cdio" software package (in "~ftp/src/cdio.shar" from the "space.mit.edu" server). Contact Dr. Peter Ford for details (see below). IBM PC Drive: Toshiba, Hitachi, Sony, or compatible. Driver: Microsoft MSCDEX version 2.2. Note: The newest version of MSCDEX (released in February 1990) is generally available. Apple Macintosh Drive: Apple CD SC (Sony) or Toshiba. Driver: Apple CD-ROM driver. Note: The Toshiba drive requires a separate driver, which may be obtained from Toshiba. Sun Micro Drive: Delta Microsystems SS-660 (Sony). Driver: Delta Microsystems driver or SUN CD-ROM Driver. Note: For questions concerning this driver, contact Denis Down at Delta Microsystems, 415-449-6881. 6. Who to Contact for Information For questions about how to read the CD-ROM: Jason J. Hyon MS 168-514 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 818-354-7050 Electronic mail addresses: SPAN: MIPL3::JJH345 Internet: jjh345@mipl3.jpl.nasa.gov NASAmail: JHYON For questions concerning the IDPT products: Jerry Clark Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 818-354-3969 For general questions about data products and documentation: Magellan Data Products Support Office Washington University Campus Box 1169 One Brookings Drive St. Louis, MO 63130 314-935-5493 Electronic mail addresses: NASA Science Internet (formerly SPAN): WURST::MGNSO Internet: mgnso@wurst.wustl.edu The Magellan Data Products Support Office is maintained by the Geosciences Node of the Planetary Data System (PDS) at Washington University. The purpose of the Support Office is to provide users of Magellan data products with information about the data and assistance in obtaining the data. Both standar and special data products are supported, including digital products, photoproducts, slides, videotapes, and NASA Public Information Office (PIO) products. The Magellan Data Products Support Office serves NASA-sponsored scientists, other researchers and educators, and the general public. The Support Office is staffed by researchers who have knowledge of Magellan data products. The primary contacts are Dr. Edward Guinness and Ms. Susan Slavney. The Office can answer questions such as what data products exist, where they can be obtained, and at what cost. The Office will also help the user place an order with the National Space Science Data Center (NSSDC). Most standard data products released by the Magellan Project are distributed by NSSDC. The user who knows exactly what products he or she wants is encouraged to call the NSSDC Coordinated Request and User Support Office at 301-286-6695 to place an order. The user who needs help in deciding what products to order, or who cannot obtain the desired products from NSSDC, should contact the Magellan Data Products Support Office for assistance. 7. Cognizant Persons Mike Martin (JPL), Gail Woodward (JPL), Peter Ford (MIT), Robert Mehlman (UCLA), and Jason Hyon (JPL) designed the PDS labels and the tables with the revisions from Ed Guinness and Susan Slavney. Edward Guinness (Washington University), Kay Edwards (USGS), Eric Eliason (USGS) and Raymond Arvidson (Washington University) helped to develop the map projection keywords and tables. Florence Moss (JPL) and Jason Hyon developed the software to generate the PDS labels and tables. Raymond Arvidson and Gail Woodward created the catalog information files, with help from Pam Woncik (JPL), Edward Guinness (Washington University), Susan Slavney (Washington University), and Mary Dale-Bannister (Washington University). The Magellan Project supplied the relevant data and information used to populate the files on this CD-ROM. Judy Mankin and Bob Canada at DADC designed the cover of this CD-ROM. This disk was produced by Jason Hyon and Paul Andres (JPL).