mar10cal

mar10cal performs radiometric corrections to images acquired by the Mariner 10 vidicon cameras. MAR10CAL performs a dark curent correction and linearization of Mariner 10 images. Key documents to refer to: MVM 73 TV Subsystem Calibration Report, M. Benesh and M. Morrill, JPL 615-148, 1973. Acquisition and Description of Mariner 10 Television Science Data at Mercury, G.E. Danielson, K.P. Klaasen, J.L. Anderson, Jour. Geophys. Research, Vol. 80, No. 17, pp 2357-2393, 1975 (and other articles in this issue). It should be noted that the flat field and sensitivity fluctuates as a function of vidicon temperature (especially for camera A). The camera heater was not functioning during encounters 2 and 3 and thus these encounters use a different calibration than the 1st encounter. Reliable non-linearity correction is thus available only for encounter 1 images. CAUTION: the program will process the encounter 2 and 3 images but the results are not reliable for any quantitative applications such as albedo measurements (absolute or relative) or photoclinometry. The situation is not hopeless, much effort has gone into deriving a fix for the 2nd and 3rd encounter frames and a future update of mar10cal will incorporate this work.

Description

An uncalibrated Mariner 10 image.

Description

The resultant radiometrically calibrated cube

Description

A cube file containing the calibration coefficients. This file should have eight bands, bands 1-4 are the coefficients for inverting the third order equation, bands 5-6 are the minimum and maximum values to process. Bands 5-6 are only used if the MASK parameter is set to "YES". If MASK is set, pixels with values outside of this range are set to NULL in the output. The mask assures that only pixels with dns in the range of the prelaunch fit are calibrated, dns outside this range are interpolations and may contain large errors. In most cases the default should be used and the files derived from the prelaunch calibration flat fields will be used. These files are named - $ISISMAR10DATA/mariner_10_"First 3 letters of FILTER_NAME"_ "INSTRUMENT_ID"_coef.cub. See also 1) Robinson et al., Jour. Geophys. Res., 97, p.18265-18274, 1992. 2) Robinson and Lucey, Science, 275, p. 197-200, 1997. 3) Robinson et al., abstracts of Lunar Planetary Sci. Conf. XXVIII, p. 1187-1188, Lunar and Planetary Inst, Houston, TX, 1997.

Description

This parameter allows the user to use an alternate dark current file. In most cases, the default should be used for this parameter to indicate the derived dark current file is to be used. The name of the derived dark current file is $ISISDATA/mariner10//mariner_10_"InstrumentId"_dc.cub. The InstrumentId wil have a value of "A" or "B".

Description

If TRUE, bands 5-6 of the coefficient cube are the minimum and maximum values to process. Any values outside of this range are set to NULL in the output file. Caution should be used in setting MASK to FALSE - the resulting dns may have less than optimal radiometric integrity.

Description

Apply blemish removal mask.

Description

Approximation for iterative solution.

Description

After dark removal and linearity correction an absolute coefficent needs to be applied to put the data in units of radiance. These coefficents (1 for each camera-filter combination) are still being refined. The values are being derived by forcing global mosaics (photometrically corrected) to Earth based measurements. for futher explanation see; 1) Robinson and Lucey, Science, 275, p. 197-200. 2) Robinson et al., abstract of Lunar Planetary Sci. Conf. XXVIII, p. 1187-1188, 1997.

Description

Offset to be added to Exposure time. If the default of NULL is used the following values are added to the offset: Camera A EXPOFF = 0.316 msecs Camera B EXPOFF = 3.060 msecs These values are taken directly from the Benesh and Morrill JPL calibration document. They state that there are some unknowns with these values... Read the section on their page 38.