PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM MISSION_NAME = GALILEO SPACECRAFT_NAME = GALILEO_ORBITER OBJECT = TEXT PUBLICATION_DATE = 2000-07-01 NOTE = "AAREADME.TXT for Galileo Jupiter Orbital Operations Solid State Imaging Raw EDR CD-ROMs (volumes GO_0017 thru GO_0022)" END_OBJECT END Galileo REDR CD-ROM 1. Introduction This data set has been generated by NASA's Galileo Project in order to distribute the images acquired by the Solid State Imaging (SSI) camera to the scientists and later to the Planetary Data System (PDS). The collection consists of all images acquired by the Galileo spacecraft during the Jupiter Orbital Operations which comprise the Prime Mission and the Galileo Europa Mission phases. Included are images of Jupiter, Ganymede, Io, Europa, Callisto, and Amalthea taken during orbits 1 through 25, as well as additional star and calibration data. This Galileo data set resides on a series of CD-ROM volumes and includes one disc of calibration and technical documentation (GO_0001). The Galileo SSI camera acquires data in a digital raster-format containing 800 scan lines and 800 samples per scan line. Each picture element (pixel) in the two dimensional image array is represented as an 8-bit value between 0 and 255, proportional to the amount of light detected at that point (with 0 being the least amount of light and 255 being the greatest amount of light). The camera is equipped with seven color filters and a clear filter such that images taken through complementary filters can be combined during ground processing to produce color images. To make full scientific use of the image collection, the radiometric and geometric properties of the camera system should be understood. All of the images in this collection are in the REDR file format described in section 4 with the exceptions of 3 reconstructed tire track images taken during Europa encounter in Orbit 12 archived in volume GO_0020 and 107 reconstructed images taken using AI8 camera telemetry mode during Io encounter in Orbit 24 archived in volume GO_0022. These reconstructed images are similar to the REDR file format except the binary header and binary prefix have been excluded (for more information, see ttds.cat in volume GO_0020 CATALOG directory for tire track reconstructed images and ai8ds.cat in volume GO_0022 CATALOG directory for reconstructed AI8 images). The original telemetry data has been processed into raster-formatted files. Multiple versions of the files, derived from separate downlinks or playbacks, have been merged together into a file of the best data. The merged data has been processed according to the SSI Imaging Team specifications. The ancillary disc, GO_0001, will provide calibration files and technical documentation necessary for the understanding of the images produced by the SSI camera. Calibration files and software are also available through the PDS Imaging Node (see Section 7 for contact information). Each of the remaining volumes contain approximately 800 images stored as VICAR files. A detached PDS label has been included for each image. Documentation files have been provided which inform the user about the organization and contents of each disc, and the definition of the labels. An index file has also been provided which contains information about the images in the data set. All PDS label formats and documentation are based on the Planetary Data System Data Preparation Workbook (D-7669, February 1995) (PDS1995) and the Planetary Science Data Dictionary (D-7116, Rev. D., JULY, 1996) (PDS1996). A brief description of the PDS label is described in the PDSLABEL.TXT file. The VICAR label is described in the VICAR2.TXT file. Both text files are located in the DOCUMENT directory. 2. Disc Format Each CD-ROM disc has been formatted such that a variety of computer systems (e.g. IBM PC, Macintosh, Sun, VAX) may access the data. Specifically, the discs are 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 disc will appear to the user to be identical to a file system of directories, subdirectories 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 which case the user must read past the first 512 bytes of the file. For further information, refer to the ISO 9660 Standard Document: RF# ISO 9660-1998, 15 April 1988. 3. 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 contents of these directories. In the table, directory names are enclosed in square brackets ([]), upper-case letters indicate an actual directory or filename and lower-case letters indicate the general form of the directory file names. It should be noted that the REDO directory may exist on a CD-ROM. This REDO directory contains those files from earlier discs which have been identified as having bad data, bad label information or missing from the volume. The new updated file has been placed in the REDO directory. The index table also contains the appropriate information regarding the new version of the file. In GO_0020 volume, a TIRETRACK subdirectory has been created under orbit E12 to archive reconstructed tire track images. There are a total of three reconstructed tire track images placed under the subdirectory and they are in a non PDS-compliant REDR file format. The index table also contains the appropriate information regarding these data images. Additional 107 reconstructed images have been archived in GO_0022 volume under orbit 24 REPAIRED subdirectory. These images are also in a non PDS-compliant REDR file format. The index table contains correspondent record entries for these data images. Top-level directory | |-AAREADME.TXT - A text file containing general information about the | data set (the file you are reading). | |-ERRATA.TXT - Summary of errors and discrepancies in specific images on | this volume and previous volumes in set. | |-VOLDESC.CAT - Volume Object describing this CD-ROM volume. | |-[CATALOG] - Directory containing files describing the data set, | | instrument, project, etc. | | | |- CATINFO.TXT - Describes the content of this directory | | | |- DATASET.CAT - Describes the Raw EDR data set | | | |- INST.CAT - Describes the SSI Instrument | | | |- INSTHOST.CAT - Describes the Galileo Orbiter Spacecraft | | | |- MISSION.CAT - Describes the Galileo Mission | | | |- PERSON.CAT - Describes contact information | | | |- REF.CAT - Includes all pertinent reference information | | | |- AI8DS.CAT - Describes the reconstructed AI8 image data set | | in this volume | |-[DOCUMENT] - Directory containing text files which describes the GLL | | Raw EDR Processing and Data Products. | | | |- DOCINFO.TXT - Describes the contents of this directory | | | |- REDRSIS.PDF - Adobe Acrobat PDF of the Software Interface | | Specification for the Raw EDR (requires | | Version 3.0 reader) | | | |- REDRSIS.HTM - HTML version of the Software Interface | | Specification for the Raw EDR | | | |- REDRSIS.LBL - A detached PDS label describing the Software | | Interface Specification for the Raw EDR | | | |- CDVOLSIS.PDF - Adobe Acrobat PDF of the Software Interface | | Specification for this volume (requires | | Version 3.0 reader) | | | |- CDVOLSIS.HTM - HTML version of the Software Interface | | Specification for this volume | | | |- CDVOLSIS.LBL - A detached PDS label describing the Software | | Interface Specification. | | | |- BADDATA.TXT - Describes the binary Bad-Data Value header. | | | |- PDSLABEL.TXT - Describes the PDS label. | | | |- VICAR2.TXT - Describes the VICAR2 image label. | | | |- AI8DOC.PDF - Adobe Acrobat PDF of the Orbit 24 AI8 camera | | anomalies and correction algorithm document in | | this volume only (requires Version 3.0 reader). | | | |- AI8DOC.HTM - HTML version of the Orbit 24 AI8 anomalies and | | correction algorithm document in this volume only. | | | |- AI8DOC.LBL - A detached PDS label describing the Orbit 24 AI8 | | camera anomalies and correction algorithm document | | in this volume only. | | | |- AI8FC.HTM - HTML version of the Orbit 24 AI8 anomalies and | | correction algorithm flow charts document in this | | volume only. | | | |- AI8FC.LBL - A detached PDS label describing the Orbit 24 AI8 | | camera anomalies and correction algorithm flow | | charts document in this volume only. | | | |-[IMAGES] - Subdirectory containing images. | | | | | |- IMAGExx.JPG - JPEG images used in the Orbit 24 AI8 camera | | | anomalies and correction algorithm document. | | | | | |- xxxxxx.PNG - PNG images used in the Orbit 24 AI8 camera | | | anomalies and correction algorithm flow charts. | | | | | |- IMAGE.LBL - A detached PDS label describing the images. | |-[INDEX] - Directory containing an index file for searching for | | specific images. | | | |- INDXINFO.TXT - Describes the contents of the index directory. | | | |- IMGINDEX.TAB - A tabular file describing basic information about | | each image on this volume. | | | |- IMGINDEX.LBL - A detached PDS label describing the contents of the | | index table. | | | |- CUMINDEX.TAB - A tabular file describing basic information about | | each image on this and previous volumes in the | | data set. Redo files from the entire volume set will | | appear at the end of this file. | | | |- CUMINDEX.LBL - A detached PDS label describing the contents of the | | cumulative index table. | | |-[LABEL] - Directory containing image engineering information. | | | |- LABINFO.TXT - Describes the contents of this directory. | | | |- RTLMTAB.FMT - A PDS format describing the binary telemetry label for | | the REDR. | | | |- RLINEPRX.FMT - A PDS format describing the binary line prefix | | information for the REDR. | |-[orbit] - Directory containing image files for a particular | Galileo orbit. J0, G1, G2, or C3, .. 25. | | |-[target] - subdirectories containing image files for a | | specific target body. | | | | |-[Crrrrrr] - These subdirectories have names of the form Crrrrrr | | | where C indicates a spacecraft clock count follows, | | | rrrrrr is the first 6 of 8 digits of the RIM count | | | of the image files. Example: C006104 | | | | | | |- rrmmR.IMG;1 - Each image data file has a unique name based | | | | on the last 2 digits of the image file | | | | RIM count appended with the MOD 91 count. | | | | The R specifies the image is in a REDR format. | | | | IMG specifies the file is the VICAR image | | | | file. Example: 0145R.IMG;1 | | | | | | | |- rrmmR.LBL;1 - The file containing the detached PDS label for | | | the image data file with the same name. | | | | | |-[repaired] - subdirectory containing orbit I24 reconstructed AI8 | | | images in this volume only. | | | | | | |-[Crrrrrr] - subdirectory has name of the form Crrrrrr where C | | | | indicates a spacecraft clock count follows, rrrrrr | | | | is the first 6 of 8 digits of the RIM count of the | | | | image files. | | | | | | | | |- rrmmS.IMG;1 - Image data filename based on the last 2 | | | | | digits of the image file RIM count appended | | | | | with the MOD 91 count. The S specifies the | | | | | image is in a special REDR format. IMG | | | | | specifies the file is the VICAR image file. | | | | | | | | | |- rrmmS.LBL;1 - The file containing the detached PDS label for the image data file with the same name. 4. Formats There are two types of experiment data records which may be produced by MIPS (Multimission Image Processing Subsystem) for the Galileo SSI Team: the Experiment Data Record (EDR) and the Raw Experiment Data Record (REDR). For the purpose of this data set, only REDR data are included. See the SSI Raw Experiment Data Record for Phase 2 Software Interface Specification (WHITE1997)located in the DOCUMENT directory. The REDR data are generated by MIPS using procedures specifically developed or adapted for Galileo. The files are generated on a VAX and are written in VAX compatible (LSByte first) format. REDR FILE FORMAT ------------------ The Galileo REDR format was originally reserved for SSI calibration data or data which should not be radiometrically corrected. The SSI Team recently determined that the REDR format will be used to archive all raw SSI data. Figure 1: REDR File Format Diagram ------------------------------------------------------ | VICAR LABEL | | | ------------------------------------------------------ | BINARY HEADER | | (Telemetry Header Record & | | Bad-Data Value Header Records) | | | ------------------------------------------------------ | | | | | | | BINARY | IMAGE DATA | | PREFIX | (Pixels) | | (Line Header) | | | | | | | | | | | ------------------------------------------------------ Each REDR file will begin with a VICAR label, followed by the REDR telemetry header, and a number of bad-data value headers followed by REDR line records. Each line record will contain 200 bytes of line header information plus the pixel data (8 bits/pixel). All records have a fixed 1000-byte length within each REDR file. All formats have 1000-byte records. Note: telemetry modes with fewer than 800 lines and 800 samples occupy lines and samples as defined in the table below (e.g., summation mode which is 400 lines and 400 samples, will occupy the first 400 lines and 400 samples of the 800 by 800 REDR). The table below lists the telemetry formats. Telemetry Downlink # Lines X Comment Format Data Rate # Samples HIS 115.2 Kbps 400 X 400 Last 6 pixels are fill HMA 115.2 Kbps 400 X 800 Last 12 pixels are fill Sample readout: 800x800; every 2nd line has data HCA 115.2 Kbps 200 X 800 Sample readout: 800x800; every 4th line has data HIM 115.2 Kbps 800 X 800 Last 12 pixels are fill IM8 806.4 Kbps 800 X 800 AI8 806.4 Kbps 400 X 400 IM4 403.2 Kbps 800 X 800 For all REDRs, the telemetry header is split into two physical records. The first 1000 bytes are placed in the first physical record after the VICAR label (the VICAR label may span more than one physical record), and the last 800 bytes are placed in the next physical record. The last 200 bytes are zero-filled. There will be a one-to-one correspondence between line records and image lines (Excluding the header records, line record 'n' will contain the data for image line 'n'). See the SSI Raw Experiment Data Record (REDR) for Phase 2 Software Interface Specification (WHITE1997) located in the DOCUMENT directory for a more detailed description of the REDR format. In addition, see the VICAR2.TXT and BADDATA.TXT files, also located in the DOCUMENT directory, and the RTLMTAB.FMT and RLINEPRX.FMT files located in the LABEL directory. 5. REDR File Naming Conventions As stated previously, each image data file is uniquely named based on the last 2 digits of the image file RIM count appended with the MOD 91 count. There are two exceptions to this rule: When an image has been returned from the on-board tape recorder more than once and the compression has changed, the MOD 91 count is incremented by one. For example, if an image with SCLK=349605600 was played back twice with different compression, there would be two REDR files, 5600R.IMG and 5601R.IMG. During on-chip mosaics, an exposure can be taken during the same frame cycle during which the readout occurs. This would normally cause the last shutter event to have the same SCLK as the readout frame. In order to ensure that the readout frame and shutter event frames have unique file names, an SCLK for the last shutter event is generated half-way between the readout frame and the previous shutter event. As a result, the on-chip mosaic with readout frame SCLK=349542200 includes shutter events 349542152, 349542165, 349542178 and 349542188. When on-chip mosaics are played back more than once with different compression, the SCLKS for the shutter events are incremented by one, as is the case for the readout frame. So if the image with SCLK=349542200 were played back a second time, the readout frame would have SCLK=349542201 and the shutter events would be: 349542153, 349542166, 349542179 and 349542189. 6. Text Files, PDS Labels, and Tabular Files All document files and detached label files contain a carriage return character (ASCII 13) and a line feed character (ASCII 10) at the end of each record. This allows the files to be read by the MacOS, DOS, Unix, and VMS operating systems. Tabular files are also described by a detached PDS label. The PDS label file has the same name as the data file it describes, with the extension .LBL; for example, the file IMGINDEX.TAB is accompanied by the detached label file IMGINDEX.LBL in the same directory. The detached PDS labels for REDR images contain information pertaining to the image. 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. 7. CD-ROM Driver Software Patch Information As stated previously, for computer software that fully supports Extended Attribute Records (XARs), access to the CD-ROM volume will be straightforward. SunOS, SGI, and PC systems running NT require software patches described below to enable access to these CD-ROMs. o Sun Micro (SunOS 4.0.3 and later) Drive: Sun Microsystems Driver: SunOS sr.o driver Note: A patch must be made to SunOS before the Sun driver can access any CD-ROM files containing Extended Attribute Records, e.g. most of the files on this disc. A copy of this patch is available to Internet users via anonymous ftp from the 'space.mit.edu' server in the file named 'src/SunOS.4.x.CD-ROM.patch'. o Silicon Graphics IRIS Drive: SGI CD-ROM Drive Driver: SGI CD-ROM driver Note: A patch must be made to SGIOS before the SGI driver can access any CD-ROM files containing Extended Attribute Records, e.g. most of the files on this disc. A copy of this patch is available by calling the PDS user support. This patch is not needed for Version 4.0.5 and above. o PC (NT version 4) Note: Three 'service packs' must be installed before accessing most of the files on this disc. Copies are available via anonymous ftp from Microsoft at the following location: ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/nt40/ 8. Calibration Calibration files and technical documentation necessary for the understanding of the images produced by the SSI camera can be found on the ancillary disc, GO_0001. Calibration files and software are also available through the VICAR software system at the PDS Imaging Node. 9. For Additional Information Contact: For questions about how to read the CD-ROM: Data Distribution Laboratory MS 171-264 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 (818) 354-9343 Electronic mail address: Internet: DDL@stargate.jpl.nasa.gov For questions concerning the Galileo REDR product and access to the calibration files and VICAR software: Tom Thaller Jet Propulsion Laboratory MS 168-514 4800 Oak Grove Drive Pasadena, CA 91109 818-354-4060 Electronic mail address: Tom.F.Thaller@jpl.nasa.gov PDS - Imaging Node Jet Propulsion Laboratory MS 168-514 4800 Oak Grove Drive Pasadena, CA 91109 Electronic mail address: pds_imaging@charlotte.jpl.nasa.gov