McIDAS Programmer's Manual
GMSCAL
GMS calibration file.
GMSCAL is a binary file that contains calibration data for GMS VIS (visible) and IR (infrared) sensor data transmitted in the GMS Stretched-VISSR real-time signal.
VIS data is 6-bit. Calibration is achieved with a 64-value VIS level-albedo lookup table. This calibration table is interpolated to make a 256-value table. IR data is 8-bit. Calibration is achieved with a 256-value IR level- temperature lookup table, which may change with the spacecraft.
The GMS calibration file is supplied with McIDAS-X.
Word allocation
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0
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number of IR calibration tables in the file
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1
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identification number of the first IR table in the file
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2
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identification number of the second IR table in the file
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511
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identification number of the 511th IR table, if present
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512 - 767
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interpolated VIS calibration table; albedos are multiplied by 10**6 and stored as integers
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1024 - 1279
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first IR calibration table in the file; it corresponds to the identifier stored in word 1; temperatures are multiplied by 10**3 and stored as integers
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1280 - 1535
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second IR calibration table in the file; it corresponds to the identifier stored in word 2 and is only present if the calibration table changes with the spacecraft
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API functions
Currently, no API library functions exist for reading and writing GMSCAL.
