NJPL1D00PDS100000000 = SFDU_LABEL NOTE = "This structure describes the columns (variables) of the data table in a Viking IRTM Chunk File. The data table is stored as a partially transposed table, but it is described here as if it were an ordinary table. The L-vector (used in the descriptions below) is the line-of-sight axis from the center of gravity of the IRTM chevron of 7 viewing spots. Angles are scaled to 80ths of a degree so that 360 degrees fits in a 16-bit signed integer. Temperatures are scaled the same way for consistency. For more information, see the text file IRTMDATA.TXT." OBJECT = OBSERVATION_NUMBER TYPE = VAX_INTEGER START_BYTE = 1 BYTES = 2 MULTIPLIER = 1.12 UNIT = SECOND NOTE = "IRTM observation time, also known as ICK: 1.12 second intervals since the start of the sequence. The latter is stored in the Sequence Table as NATIVE_START_TIME in Flight Data Subsystem (FDS) units. An ICK is equivalent to 4 FDS counts." END_OBJECT = OBSERVATION_NUMBER OBJECT = QUALITY_MASK TYPE = VAX_BIT_STRING START_BYTE = 3 BITS = 16 NOTE = "IRTM quality mask: bit flags pertaining to the data at the corresponding ICK. Bits are numbered 1 to 16, with the most significant at the left, by the PDS ODL convention. Bits 2 to 5 form a sequence of data quality indicators, from good (all 4 bits off) to poor to terrible (bit 2 on). Thus the quality mask itself may be used in an algebraic quality test. For example, requiring QUALITY < 2048 (2**11) ensures data of best quality." OBJECT = BIT_1 BIT = 1 NOTE = "Not used, always zero" END_OBJECT = BIT_1 OBJECT = BAD_DATA_FLAG BIT = 2 NOTE = "Totally bad data at this ICK -- do not use. All such data has (theoretically) been removed from this dataset." END_OBJECT = BAD_DATA_FLAG OBJECT = HIGH_UNCERTAINTY_FLAG BIT = 3 NOTE = "Uncertainty >= 8 dn for some channel(s) due to missing space value or high drift rate or imaging sequence with only 1 space look" END_OBJECT = HIGH_UNCERTAINTY_FLAG OBJECT = MODERATE_UNCERTAINTY_FLAG BIT = 4 NOTE = "VO-2 encoder dc restore on reference plate (visual band data probably ok)" END_OBJECT = MODERATE_UNCERTAINTY_FLAG OBJECT = LOW_UNCERTAINTY_FLAG BIT = 5 NOTE = "Uncertainty < 8 dn for some channel(s) but missing space value or high drift rate" END_OBJECT = LOW_UNCERTAINTY_FLAG OBJECT = CHANNEL_CORRECTION_FLAG BIT = 6 NOTE = "Some channel(s) despiked" END_OBJECT = CHANNEL_CORRECTION_FLAG OBJECT = ANOMALY_CORRECTION_FLAG BIT = 7 NOTE = "VO-2 anomaly correction applied (orbits 55-84) (bit 3 also set) or quadratic fit used for space values (VO-2 orbits > 84)" END_OBJECT = ANOMALY_CORRECTION_FLAG OBJECT = CLOCK_SLEW_NEGATIVE_FLAG BIT = 8 NOTE = "Clock slew direction is negative" END_OBJECT = CLOCK_SLEW_NEGATIVE_FLAG OBJECT = CONE_SLEW_NEGATIVE_FLAG BIT = 9 NOTE = "Cone slew direction is negative" END_OBJECT = CONE_SLEW_NEGATIVE_FLAG OBJECT = CLOCK_SLEW_RATE_FLAG BIT = 10 NOTE = "Clock slew rate >= 1/8 deg/ICK (.1 deg/sec)" END_OBJECT = CLOCK_SLEW_RATE_FLAG OBJECT = CONE_SLEW_RATE_FLAG BIT = 11 NOTE = "Cone slew rate >= 1/8 deg/ICK (.1 deg/sec)" END_OBJECT = CONE_SLEW_RATE_FLAG OBJECT = IMAGE_MOTION_COMPENSATION_FLAG BIT = 12 NOTE = "Image motion compensation geometry correction required, geometry corrected unless bit 2 is on" END_OBJECT = IMAGE_MOTION_COMPENSATION_FLAG OBJECT = POINTING_COMPUTATION_FLAG BIT = 13 NOTE = "Telemetry was used for cone & clock computations" END_OBJECT = POINTING_COMPUTATION_FLAG OBJECT = SC_ATTITUDE_COMPUTATION_FLAG BIT = 14 NOTE = "Telemetry was used for pitch, roll & yaw computations" END_OBJECT = SC_ATTITUDE_COMPUTATION_FLAG OBJECT = SCAN_PLATFORM_MOTION_FLAG BIT = 15 NOTE = "Scan platform is in motion" END_OBJECT = SCAN_PLATFORM_MOTION_FLAG OBJECT = DC_RESTORE_FLAG BIT = 16 NOTE = "A DC restore has just occurred in the IRTM instrument." END_OBJECT = DC_RESTORE_FLAG END_OBJECT = QUALITY_MASK OBJECT = PHASE_ANGLE TYPE = VAX_INTEGER START_BYTE = 5 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Phase angle at L-vector intercept" END_OBJECT = PHASE_ANGLE OBJECT = SLANT_DISTANCE TYPE = VAX_INTEGER START_BYTE = 7 BYTES = 2 UNIT = KILOMETER NOTE = "Distance (range) from spacecraft to target at L-vector intercept" END_OBJECT = SLANT_DISTANCE OBJECT = ALBEDO_DERIVATIVE_TEMPERATURE TYPE = VAX_INTEGER START_BYTE = 9 BYTES = 2 NOTE = "Derivative of model temperature with albedo at L-vector intercept (in degrees Kelvin). See NOTE under MODEL_TEMPERATURE." END_OBJECT = ALBEDO_DERIVATIVE_TEMPERATURE OBJECT = THERMAL_INERTIA_DERIVATIVE_TEMP TYPE = VAX_INTEGER START_BYTE = 11 BYTES = 2 NOTE = "Derivative of model temperature with thermal inertia at L-vector intercept (in degrees Kelvin per kieffer). See NOTE under MODEL_TEMPERATURE." END_OBJECT = THERMAL_INERTIA_DERIVATIVE_TEMP OBJECT = VIEWING_POSITION_TABLE START_BYTE = 13 ROWS = 7 ROW_COLUMNS = 11 ROW_BYTES = 22 NOTE = "The IRTM instrument has 4 telescopes, each with 7 detectors, arranged in a chevron. The telescopes are boresighted, making the chevrons coincident in object space. Thus there are 7 viewing positions, or spots, for which data is acquired simultaneously. There are 11 data table variables for each spot; only BRIGHTNESS_TEMPERATURE_3 varies in meaning for the different spots." OBJECT = INCIDENCE_ANGLE TYPE = VAX_INTEGER START_BYTE = 1 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Solar incidence angle at viewing intercept" END_OBJECT = INCIDENCE_ANGLE OBJECT = EMISSION_ANGLE TYPE = VAX_INTEGER START_BYTE = 3 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Emission (viewing) angle at viewing intercept" END_OBJECT = EMISSION_ANGLE OBJECT = LATITUDE TYPE = VAX_INTEGER START_BYTE = 5 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Latitude at viewing intercept" END_OBJECT = LATITUDE OBJECT = LONGITUDE TYPE = VAX_INTEGER START_BYTE = 7 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Longitude at viewing intercept" END_OBJECT = LONGITUDE OBJECT = LIMB_ANGLE TYPE = VAX_INTEGER START_BYTE = 9 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Limb angle at viewing intercept" END_OBJECT = LIMB_ANGLE OBJECT = LOCAL_TIME TYPE = VAX_INTEGER START_BYTE = 11 BYTES = 2 DIVISOR = 800.0 UNIT = LOCAL_HOUR NOTE = "Martian local time at viewing intercept" END_OBJECT = LOCAL_TIME OBJECT = BRIGHTNESS_TEMPERATURE_1 TYPE = VAX_INTEGER START_BYTE = 13 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "20 micron brightness temperature at viewing intercept" END_OBJECT = BRIGHTNESS_TEMPERATURE_1 OBJECT = BRIGHTNESS_TEMPERATURE_2 TYPE = VAX_INTEGER START_BYTE = 15 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "11 micron brightness temperature at viewing intercept" END_OBJECT = BRIGHTNESS_TEMPERATURE_2 OBJECT = BRIGHTNESS_TEMPERATURE_3 TYPE = VAX_INTEGER START_BYTE = 17 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "7, 9 or 15 micron brightness temperature at viewing intercept. Wavelength is 7 microns for spots 1 to 3, 9 microns for spots 4 to 6, and 15 microns for spot 7." END_OBJECT = BRIGHTNESS_TEMPERATURE_3 OBJECT = VISUAL_BRIGHTNESS TYPE = VAX_INTEGER START_BYTE = 19 BYTES = 2 DIVISOR = 10000.0 UNIT = DIMENSIONLESS NOTE = "Visual brightness at viewing intercept" END_OBJECT = VISUAL_BRIGHTNESS OBJECT = MODEL_TEMPERATURE TYPE = VAX_INTEGER START_BYTE = 21 BYTES = 2 DIVISOR = 80.0 UNIT = DEGREE NOTE = "Model temperature at viewing intercept. Reference: Kieffer, H. H., et al, J. Geophys. Res., 82, 4249-4295, 1977, Appendix 1: Viking Thermal Model." END_OBJECT = MODEL_TEMPERATURE END_OBJECT = VIEWING_POSITION_TABLE END