Data Set Overview : 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 resides on volumes GO_0002 thru GO_0006 and consists of all images acquired by the Galileo spacecraft during the period from launch in 1989 through the first encounter with the Earth (SCLK 3061100 through 62303500). Included are images of Venus, the Earth's Moon and the Earth taken during the 1990 encounters, as well as additional star, calibration and other test data.   Parameters : 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 detectessssssd 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.  The ancillary disc, GO_0001, will provide calibration files and technical documentation necessary for the understanding of the images produced by the SSI camera. Presently, calibration files and software are available through the VICAR software system at MIPS and SPICE files are available through the Galileo Science Data Team.   Processing :  REDR Processing --------------- The Raw Experiment Data Records (REDRs) were produced by the Multimission Image Processing Subsystem (MIPS) at the Jet Propulsion Laboratory using several Video Image Communications and Retrieval (VICAR) programs. The processing included the following steps:  --The original telemetry data was processed into raster-formatted files (GLLTELEMPROC)  --Multiple versions of each data file obtained from separate downlinks or playbacks were merged together to create the best version of the data (SSIMERGE)  --The VICAR label was updated to reflect the most recent pointing information (CATLABEL)  --Bad data value information was then added to the Telemetry Header (BADLABELS)  --Missing line gaps of two lines or less were filled in, as specified by the SSI Team. (GLLFILLIN)  --The PDS Index table and detached PDS label files were generated. (CDGEN)  --The VICAR files and PDS files were premastered onto a WORM CD-ROM which was validated.  --The WORM CD-ROM was sent to a vendor and CD-ROM's were generated.  --A final CD-ROM was compared bit-by-bit with the original data to ensure the quality of the vendor product.   Data : Each volume contains 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 the disc, and the definition of the labels. An index files have also been provided which contain information about the images in the data set.  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 (WHITE1993) was originally reserved for SSI calibration data or data which should not be radiometrically corrected. The SSI Team recently decided that the REDR format will be used to archive all raw SSI data.  Each REDR file consists of a VICAR label, the telemetry header, the bad-data value header records (if there are any), and the Image Data which is preceded by a Binary Prefix. There are 800 line records of image data. All records are fixed length. The line record length is 1000 bytes; 200 bytes of a binary line prefix and 800 bytes of 8 bit pixel data. (Note, for the AI8 format or summation mode, the record length is still 1000, but the data is placed in the first 400 pixel samples and 400 lines only.) There will be a one-to-one correspondence between line records and image lines. Data not received will be zero-filled.  The BINARY HEADER is composed of a Telemetry header and a Bad-Data Value Header containing ancillary information specific to the image. The TELEMETRY HEADER is split into two physical records. The first 1000 bytes are placed in the first physical record after the VICAR label, and the last 800 bytes are placed in the next physical record. The last 200 bytes are zero filled. The BAD-DATA VALUE HEADER is composed of records describing several types of bad data values. Each record describes only one type and depending on the number of bad pixels, they may span over several physical records. Each record is identified by the Record IDS field which is located at byte 0.   Ancillary Data : 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.   Software : The following CD-ROM copy, display and processing software has been successfully tested using the Galileo SSI data:   Copy Software ------------- -- DCL COPY (VMS) - available with VMS  -- VICAR Copy (VMS and UNIX) - Available with VICAR package from COSMIC.   Display Software ---------------- -- VICAR JDISP (VMS and UNIX) - Available with VICAR package from COSMIC.  -- PIXEL PUSHER (Apple Macintosh) - Available from COSMIC.  -- NIH IMAGE (Apple Macintosh) - A public domain program available from the National Institute of Health.  -- CDBROWSE (UNIX/Motif) - Software may be obtained from richard@ben.jpl.nasa.gov on the internet.  -- IMDISP (IBM PC) - Program and information about this program are available from PDS.   Processing Software ------------------- --VICAR (VMS and UNIX) - Available from COSMIC  --ISIS (VMS and UNIX) - Available through the USGS in Flagstaff   Media/Format : N/A

Confidence Level Overview : The SSI REDRs contain raw data as received from Galileo telemetry. All the images received were processed and are contained on this volume. Included in the limitations section are explanations of the VICAR and PDS keywords and values, as well as a description of a problem found with one frame in the data set. This data set contains all of the data acquired during the Venus and Earth 1 period, the processing has been verified, and is currently in use by science team members in their analysis   Review : The SSI REDRs are reviewed prior to archiving by the SSI team. Data received is compared with data expected, and replays of missing data is requested. The status and validity information on the REDRs themselves is examined. Format and documentation of the CD-ROM archive volume is reviewed by PDS and is documented in WAINIO1992. The mastered and replicated CD-ROM volumes received from the vendor are compared bit-by-bit with the original data to ensure the quality of the product.   Data Coverage and Quality :  Sequences and Objectives ------------------------ VFWS Venus Pre-Encounter Lightning VVLM Venus Limb WFT Venus Feature Track WGL Venus Global WLT Venus Departure Lighning LESH Lunar Single Filter include Earthshine LCLR Lunar Multispectral WZGF Earth Zoom Geology Feature WSPN Earth Spin Movie WROT Earth Rotation Movie (daily samples) WDRK Earth Darkside LCAL Earth Camera Calibration   Limitations : This section documents the known bad images, blank or saturated lunar frames and any problems which have been currently identified in the Venus/Earth I dataset. For the purpose of this memo CD's refers to the five Earth I SSI REDR CD-ROM's (GO_0002 through GO_0006). GO_0001 is scheduled to be generated after all of the IDA has been received sometime in the mid-1994 time period.   General Information ------------------- The following datasets are included on the CD's. The starting and ending SCLK's (rim + mod91) have been identified, as well as any general information that might be needed to document the dataset.   Post Launch Checkout -------------------- (data taken after launch)  SCLK range: 3061100 - 3061945 - No SPICE info available  - VICAR/PDS labels incomplete due to lack of SPICE info. (e.g. no SCET)   MINICAL ------- (calibration frames taken before Venus)  SCLK range: 11890900 - 11895526 - No SPICE info available  - VICAR/PDS labels incomplete due to lack of SPICE info. (e.g. no SCET)   VENUS ----- SCLK range: 18062552 - 19064100 - SPICE available  - PICNO not available in Mini-E kernel (i.e. not in VICAR/PDS labels)  - Activity id not in standard format.   PRE-EARTH CALIB --------------- SCLK range: 59335800 - 59905000 - SPICE available  - Additional no shutter frames were captured for which no predict/SPICE info was available (identified as activity_id:NO_SHUTTER   EARTH I/MOON ------------ SCLK range: 60959100 - 62303500 - SPICE available   Bad Frames ---------- The following is a the list of known bad SSI frames provided by Ken Klaasen on April 9, 1992. This is not an all inclusive list, but it does provide the major problems identified through Earth I. Appendix A contains the listing of lunar frames which were blank, saturated or redundant.  11894613 - 11894726 - Garbled Jupiter frames due to IM-4 problem.  18062600 - 18062639 - Venus darkside frames saturated due to scattered light.  59466845 - 59480800 - PCT frames that missed target due to error in pointing command.   VICAR Labels : Definitions for VICAR field names can be found in WHITE1993.  A) The RAD field (ring radius at frame center) within the VICAR label was not applicable and is equal to 0.0, for the entire set of CD's,.  B) The following fields in the VICAR label were not implemented for the entire set of CD's.  CONE : 0.0 HRA : -999.0 SMEAR : -999.0 SMRAZ : 0.0 SOLRANGE : 7.779091 TCA : 'closest time'  C) For targets other than a planetary body or asteroid (e.g. black sky, stars, calibration etc.) most pointing information is not available. A listing of the missing fields is provided below. More detailed information can be found in the CATSTATUS.TXT file which located in the Documents directory on all of the CD's,.  EMA : -999.0 HSCL : 0.0 INA : -999.0 LAT : 0.0 LON : 0.0 NORAZ : 0.0 PHA : -999.0 PLRANGE : 0.0 SCAZ : 0.0 SLRANGE : 0.0 SUNAZ : 0.0 VSCL : 0.0  D) When SPICE information is unavailable (e.g. Post launch checkout, Minical, additional No shutter frames) the following CATSTATUS for more detailed information.  DEC : 0.0 EMA : -999.0 HSCL : 0.0 INA : -999.0 LAT : 0.0 LON : 0.0 NORAZ : 0.0 PHA : -999.0 PICNO : '?' PLRANGE : 0.0 RA : 0.0 SCAZ : 0.0 SCETYEAR : -32768 SCETDAY : -32768 SCETHOUR : -32768 SCETMIN : -32768 SCETSEC : -32768 SCETMSEC : -32768 SLRANGE : 0.0 SUNAZ : 0.0 TWIST : 0.0 VSCL : 0.0  E) PLRANGE is equivalent to the spacecraft target range instead of the spacecraft central body range. This affects the lunar frames only since the PLRANGE defines the distance from the Moon rather than from the Earth. For the rest of the dataset, the spacecraft target range is equivalent to the spacecraft central body range so PLRANGE is correct.   PDS Labels : Definations for PDS field names can be found in CRIBBS1992.  A) The following PDS fields were not applicable for the entire set of CD's .  BLEMISH_FILE_NAME : 'N/A' CENTER_RING_RADIUS : 0.0 DARK_CURRENT_FILE_NAME : 'N/A' EDR_FILE_NUMBER : 'N/A' EDR_TAPE_ID : 'N/A' MEAN_RADIANCE : 'N/A' MEAN_REFLECTANCE : 'N/A' ORBIT_NUMBER : 'unk' or 12613 RADIANCE_SCALING_FACTOR : 'N/A' REFLECTANCE_SCALING_FACTOR : 'N/A' SHUTTER_OFFSET_FILE_NAME : 'N/A' SLOPE_FILE_NAME : 'N/A' SPICE_FILE_NAME : 'unk' UNEVEN_BIT_WEIGHT_CORR_Flag : 'N/A'  B) The following PDS fields were not implemented for the entire set of CD's.  CONE_ANGLE :0.000 LOCAL_HOUR_ANGLE :'unk' SMEAR_AZIMUTH :0.000 SMEAR_MAGNITUDE :'unk' SOLAR_DISTANCE :7.779091  C) For targets other than a planetary body or asteroid (e.g. black sky, stars, calibration etc.) the following pointing information is not available in the PDS labels.  A_AXIS_RADIUS : 'unk' B_AXIS_RADIUS : 'unk' C_AXIS_RADIUS : 'unk' CENTER_LATITUDE : 0.00000 CENTER_LONGITUDE : 0.00000 CENTRAL_BODY_DISTANCE : 0.00000 EMISSION_ANGLE : 'unk' HORIZONTAL_PIXEL_SCALE : 0.00000 INCIDENCE_ANGLE : 'unk' NORTH_AZIMUTH : 0.000 PHASE_ANGLE : 'unk' SATELLITE_TIME_FROM_CLST_APR : 'unk' SLANT_DISTANCE : 0.00000 SUB_SOLAR_AZIMUTH : 0.000 SUB_SOLAR_LATITUDE : 'unk' SUB_SOLAR_LONGITUDE : 'unk' SUB_SPACECRAFT_AZIMUTH : 0.000 SUB_SPACECRAFT_LATITUDE : 'unk' SUB_SPACECRAFT_LINE : 'unk' SUB_SPACECRAFT_LINE_SAMPLE : 'unk' SUB_SPACECRAFT_LONGITUDE : 'unk' TARGET_CENTER_DISTANCE : 'unk' TIME_FROM_CLOSEST_APPROACH : 'unk' VERTICAL_PIXEL_SCALE : 0.00000  D) When SPICE information is unavailable (e.g. Post launch checkout, Minical, additional No shutter frames) the following pointing fields in the PDS label are not available.  A_AXIS_RADIUS : 'unk' B_AXIS_RADIUS : 'unk' C_AXIS_RADIUS : 'unk' CENTER_LATITUDE : 0.000 CENTER_LONGITUDE : 0.000 CENTRAL_BODY_DISTANCE : 0.00000 DECLINATION : 0.000 EMISSION_ANGLE : 'unk' HORIZONTAL_PIXEL_SCALE : 0.00000 IMAGE_ID : 'unk' IMAGE_TIME : 'unk' INCIDENCE_ANGLE : 'unk' NORTH_AZIMUTH : 0.000 PHASE_ANGLE : 'unk' RIGHT_ASCENSION : 0.000 SATELLITE_TIME_FROM_CLST_APR : -73T... or 'unk' SLANT_DISTANCE : 0.00000 SUB_SOLAR_AZIMUTH : 0.000 SUB_SOLAR_LATITUDE : 'unk' SUB_SOLAR_LONGITUDE : 'unk' SUB_SPACECRAFT_AZIMUTH : 0.000 SUB_SPACECRAFT_LATITUDE : 'unk' SUB_SPACECRAFT_LINE : 'unk' SUB_SPACECRAFT_LINE_SAMPLE : 'unk' SUB_SPACECRAFT_LONGITUDE : 'unk' TARGET_CENTER_DISTANCE : 'unk' TIME_FROM_CLOSEST_APPROACH : -73T... or 'unk' TWIST_ANGLE : 0.000 VERTICAL_PIXEL_SCALE : 0.00000  E) On CD-ROM GO_0002 only, the INVERTED_CLOCK_STATE_FLAG was incorrectly set using the LIGHT_FLOOD_STATE_FLAG. The INVERTED_CLOCK_STATE_FLAG should have read NOT INVERTED for all frames except for the 59335800, 59335900, 59336000, 59336100, 59336200, 59336400.  F) ORBIT_NUMBER for Earth and Moon frames incorrectly reads 12613 instead of UNK.   PDS Index Table : A) The following fields in the PDS Index table were not applicable for the entire set of CD's, .  CENTER_RING_RADIUS : 0.0 MEAN_RADIANCE : 'N/A' MEAN_REFLECTANCE : 'N/A' ORBIT_NUMBER : 'unk' or 126 RADIANCE_SCALING_FACTOR : 'N/A' REFLECTANCE _SCALING_FACTOR : 'N/A'  B) The following fields in the PDS Index table were not implemented for the entire set of CD's.  CONE_ANGLE : 0.000 LOCAL_HOUR_ANGLE : 'unk' SMEAR_AZIMUTH : 0.000 SMEAR_MAGNITUDE : 'unk' SOLAR_DISTANCE : 7.779091  C) For targets other than a planetary body or asteroid (e.g. black sky, stars, calibration etc.) some pointing information is not available. A listing of the missing fields is provided below.  CENTER_LATITUDE : 0.00000 CENTER_LONGITUDE : 0.00000 CENTRAL_BODY_DISTANCE : 0.00000 EMISSION_ANGLE : 'unk' HORIZONTAL_PIXEL_SCALE : 0.00000 INCIDENCE_ANGLE : 'unk' NORTH_AZIMUTH : 0.000 PHASE_ANGLE : 'unk' SATELLITE_TIME_FROM_CLST_APR : -73T... or ' unk' SLANT_DISTANCE : 0.00000 SUB_SOLAR_AZIMUTH : 0.000 SUB_SOLAR_LATITUDE : 'unk' SUB_SOLAR_LONGITUDE : 'unk' SUB_SPACECRAFT_LATITUDE : 'unk' SUB_SPACECRAFT_LINE : 'unk' SUB_SPACECRAFT_LINE_SAMPLE : 'unk' SUB_SPACECRAFT_LONGITUDE : 'unk' TARGET_CENTER_DISTANCE : 'unk' TIME_FROM_CLOSEST_APPROACH : -73T... or 'unk' VERTICAL_PIXEL_SCALE : 0.00000  D) When SPICE information is unavailable (e.g. Post launch checkout, Minical, additional No shutter frames) the following pointing fields in the Index table are not available.  CENTER_LATITUDE : 0.00000 CENTER_LONGITUDE : 0.00000 CENTRAL_BODY_DISTANCE : 0.00000 DECLINATION : 0.000 EMISSION_ANGLE : 'unk' HORIZONTAL_PIXEL_SCALE : 0.00000 IMAGE_ID : 'unk' IMAGE_TIME : -3276.. or 0-00-00T.. INCIDENCE_ANGLE : 'unk' NORTH_AZIMUTH : 0.000 PHASE_ANGLE : 'unk' RIGHT_ASCENSION : 0.000 SATELLITE_TIME_FROM_CLST_APR : -73T... or unk' SLANT_DISTANCE : 0.00000 SUB_SOLAR_AZIMUTH : 0.000 SUB_SOLAR_LATITUDE : 'unk' SUB_SOLAR_LONGITUDE : 'unk' SUB_SPACECRAFT_LATITUDE : 'unk' SUB_SPACECRAFT_LINE : 'unk' SUB_SPACECRAFT_LINE_SAMPLE : 'unk' SUB_SPACECRAFT_LONGITUDE : 'unk' TARGET_CENTER_DISTANCE : 'unk' TIME_FROM_CLOSEST_APPROACH : -73T... or 'unk' TWIST_ANGLE : 0.000 VERTICAL_PIXEL_SCALE : 0.00000  E) When TARGET_CENTER_DISTANCE or CENTER _BODY_DISTANCE are equal to UNK, the right double quote is missing in the index table.   REDO Directory (GO_0006) : The following files have been reprocessed and placed in the REDO directory located on GO_0006. The files were previously located in the Target and Directory indicated in the below table. There were three cases in which data was reprocessed. Case 1 - several files had bad VICAR labels as indicated earlier in this memo. Case 2 - when gap fill in was requested and either the line above or below the gap contained a Reed-Solomon overflow error. Case 3 - there was one file in which the data on the CD-ROM was found to be corrupted. All data was reprocessed, a new PDS label created and the information added to the INDEX table on GO_0006.  18062639 - Venus - C001806 - Bad VICAR label 18241745 - Venus - C001824 - Bad VICAR label & Reed-Solomon fillin problem 18353518 - Venus - C001835 - Bad VICAR label 18518445 - Venus - C001851 - Bad VICAR label 59469700 - Black Sky - C005946 - Bad VICAR label 59471700 - Black Sky - C005947 - Bad VICAR label 60964000 - Moon - C006096 - Reed-Solomon fillin problem 61078900 - Earth - C006107 - Reed-Solomon fillin problem 61116300 - Moon - C006111 - Reed-Solomon fillin problem 61116600 - Moon - C006111 - Reed-Solomon fillin problem 61424500 - Earth - C006142 - Reed-Solomon fillin problem 61441500 - Earth - C006144 - Reed-Solomon fillin problem 61469100 - Earth - C006146 - Reed-Solomon fillin problem 61508200 - Earth - C006150 - Bad image 61509700 - Earth - C006150 - Reed-Solomon fillin problem 61510400 - Earth - C006151 - Reed-Solomon fillin problem 61510800 - Earth - C006151 - Reed-Solomon fillin problem 61512600 - Earth - C006151 - Reed-Solomon fillin problem 61516300 - Earth - C006151 - Reed-Solomon fillin problem 61516400 - Earth - C006151 - Reed-Solomon fillin problem 61516700 - Earth - C006151 - Reed-Solomon fillin problem 61522100 - Earth - C006152 - Reed-Solomon fillin problem 61525200 - Earth - C006152 - Reed-Solomon fillin problem 61526200 - Earth - C006152 - Reed-Solomon fillin problem 61530600 - Earth - C006153 - Reed-Solomon fillin problem 61531400 - Earth - C006153 - Reed-Solomon fillin problem 61531700 - Earth - C006153 - Reed-Solomon fillin problem 61533800 - Earth - C006153 - Reed-Solomon fillin problem 61535500 - Earth - C006153 - Reed-Solomon fillin problem 61539600 - Earth - C006153 - Reed-Solomon fillin problem 61542500 - Earth - C006154 - Reed-Solomon fillin problem   Reed-Solomon Overflow : Many of the images in this dataset contain a Reed-Solomon overflow. This feature may be seen in images which were Reed-Solomon encoded by the Galileo spacecraft. If the data was received on the ground and the Reed-Solomon decoder was unable to completely decode the data, this overflow feature is present in the data.  The Reed-Solomon overflow feature may be identified by the following criteria. It is present on a single line or series of lines. It starts about midway through a line and always continues through sample 800. The data numbers (dn's) can shift between white, black or shades of gray. In some cases, the dn's may be just a few dn brighter or darker than the surrounding lines. Reed-Solomon overflows should not be confused with the data gaps caused by the decompression of data. Decompression gaps are usually at the extreme right of an image, they always have a dn:0 (black) and they are clearly identified in the VICAR Binary Prefix.  It should be noted that the Reed-Solomon overflows have not been identified in any way within this dataset. Future data acquired by the SSI instrument will have a flag, in the Binary Prefix of the VICAR label, which will identify when a Reed-Solomon overflow has occurred.   New Information About Venus/Earth I data set -------------------------------------------- After the final Venus/Earth I data set memorandum was released, additional information about the data set has been identified. First, one black sky image was found to be missing from the data set. This frame (59466445) was processed and placed in the REDO directory located on GO_0007.  The longitude values for the VENUS frames in the various headers are in WEST longitude not the more commonly used EAST longitude.  The text file name CATSTATUS.TXT is too long for the ISO convention of 8.3. This has been shortened to CATSTAT.TXT for the Earth 2 CDs.  The PDS fields TIME_FROM_CLOSEST_APPROACH and SATELLITE_TIME_FROM_ CLST_APR are not in the standard PDS DATE/TIME format. Since these fields are not a date and only a time, PDS is in the process of defining a new data type for these keywords. PDS software is being modified to handle the Galileo usage of these fields.  The PDS fields RIGHT_ASCENSION and TWIST are not in the PDS defined range of values. These keywords should have values in the range of 0 to 360 degrees and instead have been defined in the range of -180 to 180 degrees. To get the 0 to 360 range, software should take the value from the PDS label, add 360 and then take the mod of 360. It should be noted that the VICAR header and various VICAR software use the -180 to 180 degree convention. The PDS fields in the Earth 2 CDs are provided in the 0 to 360 degree conventions.