PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM SPACECRAFT_NAME = "MARS GLOBAL SURVEYOR" TARGET_NAME = "MARS" OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 1999-02-22 END_OBJECT = TEXT END MGSC_0001: Image AB-1-018/03 was only partially contained in the packets archived on CD-ROM by the MGS Project. A version based on data retrieved on 10/10/1997 from the JPL telemetry system contained nearly a megabyte of additional image data. We have archived the image derived from these additional packets as well as the packets that are on the CD. We suspect a bug in the JPL "besting" algorithm or in the process which archived the packets. The affected CD file is for year 1997, day 284, hour 12. Four images on this volume (AB-1-004/01, AB-1-004/02, AB-1-005/06, and AB-1-016/03) have incorrectly computed values for the NORTH_AZIMUTH and SUB_SOLAR_AZIMUTH fields in the imgindx.tab file, which are displayed as "NaN" (Not a Number, indicating IEEE floating point error handling of conditions such as divide by zero.) These fields should have the NOT_APPLICABLE_CONSTANT of 0.00 as they could not be computed from available information. These errors are corrected in the cumindx.tab file starting on volume MGSC_0004. MGSC_0002: Images AB-1-069/01 and AB-1-072/01 did not have all C-kernel (pointing) information available and were assumed to be nadir-pointed. Images AB-1-069/07 and AB-1-075/06 have complex geometry with respect to the south pole which exposed a bug in the calculation of the USAGE_NOTE; in both cases the flag should be "N". MGSC_0003: Images AB-1-109/01, AB-1-109/02, AB-1-109/03, AB-1-109/04, AB-1-109/05, AB-1-135/01, AB-1-135/02, AB-1-135/03, AB-1-135/04, AB-1-135/05, and AB-1-135/06 did not have all C-kernel (pointing) information available and were assumed to be nadir-pointed and +X forward. For these orbits the spacecraft was oriented +X backward (with its +X axis against rather than with the velocity vector), so the USAGE_NOTEs should be inverted in all cases and the corner coordinates similarly flipped left-to-right. Image AB-1-103/05 has complex geometry with respect to the south pole which exposed a bug in the calculation of the USAGE_NOTE; the flag should be "N". MGSC_0001, MGSC_0002, MGSC_0003: The imgindx.lbl and cumindx.lbl files on these three volumes have errors in the START_BYTE field caused by an incorrect data type for the EDIT_MODE_ID field and an incorrect byte count for the NORTH_AZIMUTH field. These files are corrected on subsequent volumes, and the cumindx.lbl file on those volumes should be consulted. After production, errors were found in the GAIN_MODE_ID and OFFSET_MODE_ID fields for the following images: AB-1-005/06 -- GAIN_MODE_ID "2A" AB-1-023/05 -- OFFSET_MODE_ID "22" AB-1-029/08 -- OFFSET_MODE_ID "20" AB-1-034/04 -- GAIN_MODE_ID "1A", OFFSET_MODE_ID "1" AB-1-037/05 -- GAIN_MODE_ID "0A", OFFSET_MODE_ID "72" AB-1-040/05 -- GAIN_MODE_ID "0A", OFFSET_MODE_ID "69" AB-1-044/05 -- GAIN_MODE_ID "2A", OFFSET_MODE_ID "55" AB-1-047/06 -- GAIN_MODE_ID "2A", OFFSET_MODE_ID "84" AB-1-050/04 -- OFFSET_MODE_ID "76" AB-1-055/04 -- OFFSET_MODE_ID "71" AB-1-063/04 -- GAIN_MODE_ID "4A", OFFSET_MODE_ID "56" AB-1-063/05 -- GAIN_MODE_ID "4A", OFFSET_MODE_ID "56" AB-1-065/04 -- OFFSET_MODE_ID "58" AB-1-065/05 -- OFFSET_MODE_ID "48" AB-1-072/04 -- GAIN_MODE_ID "EA", OFFSET_MODE_ID "14" AB-1-074/04 -- OFFSET_MODE_ID "56" AB-1-074/05 -- OFFSET_MODE_ID "60" AB-1-088/04 -- GAIN_MODE_ID "4A", OFFSET_MODE_ID "82" AB-1-095/05 -- GAIN_MODE_ID "CA", OFFSET_MODE_ID "31" AB-1-096/04 -- OFFSET_MODE_ID "65" AB-1-104/08 -- GAIN_MODE_ID "8A", OFFSET_MODE_ID "32" AB-1-108/04 -- OFFSET_MODE_ID "20" AB-1-108/05 -- GAIN_MODE_ID "6A", OFFSET_MODE_ID "40" AB-1-110/03 -- OFFSET_MODE_ID "44" AB-1-111/03 -- GAIN_MODE_ID "2A", OFFSET_MODE_ID "57" AB-1-112/03 -- OFFSET_MODE_ID "32" AB-1-113/03 -- GAIN_MODE_ID "8A", OFFSET_MODE_ID "14" AB-1-114/03 -- GAIN_MODE_ID "8A", OFFSET_MODE_ID "13" AB-1-118/03 -- GAIN_MODE_ID "4A", OFFSET_MODE_ID "44" In addition, the LINE_EXPOSURE_DURATION for AB-1-003/03 was actually 71.68 milliseconds. These errors are corrected in the cumindx.tab file starting on volume MGSC_0004. In addition, the image files themselves, with corrected image headers, are in the directory "ab1fixes" on MGSC_0005. MGSC_0004: Images 211/02, 211/03, 211/05, 227/01, 227/02, 227/04, 245/05, 246/01, 246/02, 246/03, and 246/04 did not have pointing information and were assumed nadir-pointed. The packets archived by the MGS Project on CD-ROM are ordered incorrectly for orbit 216. This results is incorrect processing by our telemetry tools. We have archived an intermediate product based on data retrieved during operations until this problem is resolved. The file affected is for year 1998, day 93, hour 6. MGSC_0005: Images 263/01, 263/02, 263/03, 265/01, 265/02, and 265/04 did not have pointing information and were assumed nadir-pointed. MGSC_0006: Images 372/01 and 372/02 did not have pointing information and were assumed nadir-pointed. MGSC_0008: Images 465/01, 465/02, 467/02, 467/03, 471/01, and 471/02 did not have pointing information and were assumed nadir-pointed. MGSC_0009: Images 498/01, 498/02, 498/03, 498/99, 504/01, 504/02, 504/03, 504/04, 504/99, 506/99, 508/01, 508/99, 510/99, 517/01, 517/02, 517/06, 525/01, 525/02, 525/03, 525/04, and 525/99 did not have pointing information and were assumed nadir-pointed. Note that the "99" images are filler images, usually of space, and are included for archival completeness. MGSC_0010: All images from the Phobos orbits (476, 501, 526, and 551) were processed with Phobos position information from the NAIF SP kernel file mar033-5.bsp. Owing to limitations in our processing software, coordinate information is relative to the IAU triaxial ellipsoid model of Phobos in some instances, and relative to a spheroid with equatorial radius 13.4 km and polar radius 9.2 km in other instances, and should be treated with some caution. C-kernel information was not available for Phobos images 526/01, 526/02, and 526/03, and in these cases the ancillary values are grossly in error. General: As of the production of this volume, there were no known general errata.