PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 40 FILE_RECORDS = 4 ^TABLE = "GAINOFF.TAB" OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 4 ROW_BYTES = 40 COLUMNS = 6 DESCRIPTION = "The data in this table are used to compute the photosensor array output voltage from an image digital number (DN). The data are taken from Huck et al., Radiometric Performance of the Viking Mars Lander Cameras, NASA TM X-72692, 1975. Voltage is computed as follows: v = (2**GN)*(DN/4)/Kg + K1*OFN - K2 where v = voltage in units of volts, GN = gain number from the PDS image label, DN = digital number from the image, Kg = gain constant, K1 = offset constant 1, OFN = offset number from the PDS image label, and K2 = offset constant 2. The digital number is divided by 4 because the original data returned from the spacecraft were 6-bits in length and then converted to 8-bits by multiplying by 4. The constants in this table vary by a small amount as a function of gain, offset, and temperature. These small variations are discussed in Wolf et al., Viking Lander Camera Radiometry Calibration Report, JPL Pub. 77-62, 1977." OBJECT = COLUMN NAME = LANDER_NUMBER DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "The number of the Viking Lander, either 1 or 2." END_OBJECT = COLUMN OBJECT = COLUMN NAME = CAMERA_NUMBER DATA_TYPE = ASCII_INTEGER START_BYTE = 4 BYTES = 2 DESCRIPTION = "The number of the camera on one of the Viking Landers, either 1 or 2." END_OBJECT = COLUMN OBJECT = COLUMN NAME = INSTRUMENT_SERIAL_NUMBER DATA_TYPE = CHARACTER START_BYTE = 8 BYTES = 5 DESCRIPTION = "The manufacturer's serial number assigned to an instrument. It is used to uniquely identify an instrument in tracing its components or determining its calibration history." END_OBJECT = COLUMN OBJECT = COLUMN NAME = GAIN_CONSTANT DATA_TYPE = ASCII_REAL START_BYTE = 15 BYTES = 8 FORMAT = "F8.3" DESCRIPTION = "The value for Kg in the DN to voltage equation for Viking Lander image data." END_OBJECT = COLUMN OBJECT = COLUMN NAME = OFFSET_CONSTANT_1 DATA_TYPE = ASCII_REAL START_BYTE = 24 BYTES = 8 FORMAT = "F8.5" DESCRIPTION = "The value for K1 in the DN to voltage equation for Viking Lander image data." END_OBJECT = COLUMN OBJECT = COLUMN NAME = OFFSET_CONSTANT_2 DATA_TYPE = ASCII_REAL START_BYTE = 33 BYTES = 6 FORMAT = "F6.3" DESCRIPTION = "The value for K2 in the DN to voltage equation for Viking Lander image data." END_OBJECT = COLUMN END_OBJECT = TABLE END