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ISIS 3 Application Documentation


mical

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Radiometrically calibrates a Mars Exploration Rover (MER) Microscopic Imager(MI) image

Overview Parameters

Description

mical performs radiometric corrections to images acquired by the MER MI camera. MI images taken during science operations have 1024 samples and 1024 lines and are single bands. The pre calibration images are signed word or 16 bit images. Subareas can be aquired but this was rarely done during the mission.
mical has a number of parameters required to process MER MI image data. Most of these parameters are read from an ISIS parameter defaults file located in the mer directory specified in the IsisPreference file. This file has the form:

      $mer/calibration/mical.ker.xxx

      where "xxx" is a positive number.
     
mical will search for the parameter file with the highest number and load all its defaults needed to process MI images. Note that the caller may explicity provide an alternative ISIS parameter defaults file name in the "CALKERNEL" input parameter if they have their own set of defaults that applies to MI data. See an existing calibration file for details on how to configure this file.

The level of calibration output can be selected. by choosing one of the output options, the user can choose to dark current correct, dark current and flat field, or dark current, flat field and output in I/F values.

The dark current correction equation mical implements is as follows:

      r = dn - (rpi + rpv) + (zei * zev) + (aai * aav)
    
Where: r is the aver signal being generated at the focal plane dn is the input pixel value rpi is the referance pixel dn rpv is the referance pixel correction value zei is the zero exposure pixel dn zev is the zero exposure correction value aai is the active area pixel dn aav is the active area correction value The user can choose to not correct for the reference pixel, zero exposure or active area by selecting or deselecting the RPCORRECTION, ZECORECTION, or AACORRECTION checkbox. The program will also determain if these corrections should be applied. If the ShutteEffectCorrectionFlag is set to "TRUE" in the image labels, the reference pixel, and zero exposure will not be applied.
If a flat fielded output is chosen:
       r = dn / f
     
where: r is the corrected output value dn is the input pixel that has been dark current corrected f is a flat field pixel
if the "ShutteEffectCorrectionFlag is false and the exposure duration is greater them zero and less them 1000 and the image is mot equal to 1024 samples, a image smear correction is applied.


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History

Robert Sucharski2007-02-16 Original version
Christopher Combs2017-05-19 Changed pvl.DIFF of input for all app tests to ignore file names. Allows test to pass when not using default data area. Fixes #4738.

Parameter Groups

Files

Name Description
FROM Level 0 MER MI image
TO Level 1 MER MI image
CALKERNEL PVL kernel containing calibration prameters
REFPIXIMAGE Referance Pixel image (ERP)
FLATFIELD The flat field image used in correction

Output Options

Name Description
CALSTAGE The calibration stage to process

Entry Option

Name Description
CCDtemp CCD temperature
PCBtemp PCB temperature
RPCORRECTION Correct for Referance Pixel
ZECORRECTION Correct for Zero Exposure
AACORRECTION Correct for Active Area
X

Files: FROM


Description

An uncalibrated MER MI image.

Type cube
File Mode input
Filter *.cub *.CUB
Close Window
X

Files: TO


Description

The resultant radiometrically calibrated cube

Type cube
File Mode output
Pixel Type real
Filter *.cub *.CUB
Close Window
X

Files: CALKERNEL


Description

If you do not enter a file, mical will search for a file with the form:

            $mer/calibration/mical.kernel.xxx

            where "xxx" is a positive number.
          
the kernel with the highest version (xxx) will be used. See an existing calibration file for details on how to configure this file.

Type filename
File Mode input
Internal Default Internal Default
Close Window
X

Files: REFPIXIMAGE


Description

At times, a referance pixel image was aquired when image data was taken. If a referance pixel image was acquired, it can be used in the calibration. A referance pixel image uses the designation "ERP" rather then "EFF" in the file name.

Type cube
File Mode input
Internal Default Use Model Value
Filter *.cub *.CUB
Close Window
X

Files: FLATFIELD


Description

User can enter a flat field image that will be used in the correction. If no value is entered, then the file listed in the calibration kernel will be used.

Type cube
File Mode input
Internal Default Use value in kernel
Filter *.cub *.CUB
Close Window
X

Output Options: CALSTAGE


Description

This parameter allows the user to control what calibration step will be applied to the input image. if "DARK" is selected, then only a dark current correction is preformed. If "FLAT" is selected, the image is corrected for dark current and a flat field correction is applied. if "IOF" is chosen then the final outut will in refiectance values.

Type string
Default IOF
Option List:
Option Brief Description
DARK Dark Current correction The output file will be a dark current corrected file.
FLAT Dark Current and Flat Field correction The output will be a dark current corrected and flat field corrected. This is the "CFD" image in the PDS archive.
IOF Convert Dark current and Flat Field corrected image to I/F values The output file will be a flat field corrected image that has been converted to refiectance. This is the "IFF" file in the PDS archive.
Close Window
X

Entry Option: CCDtemp


Description

A user defined CCD temperature that will be used in calculations that use the CCD temperature. If entered, this value will be used rather then the temperature in the image labels.

Type double
Internal Default Temperature from Labels
Close Window
X

Entry Option: PCBtemp


Description

A user defined PCB temperature that will be used in calculations that use the PCB temperature. If entered, this value will be used rather then the temperature in the image labels.

Type double
Internal Default Temperature from labels
Close Window
X

Entry Option: RPCORRECTION


Description

If this option is selected, the reference pixel correction will be applied. if the ShutteEffectCorrectionFlag is set to TRUE then the reference pixel correction is not applied, even if this parameter is set to true. The default is true which will apply the correction.

Type boolean
Default TRUE
Close Window
X

Entry Option: ZECORRECTION


Description

If this option is selected, the zero exposure correction will be applied. if the ShutteEffectCorrectionFlag is set to TRUE then the zero exposure correction is not applied, even if this parameter is set to true. The default is true which will apply the correction.

Type boolean
Default TRUE
Close Window
X

Entry Option: AACORRECTION


Description

If this option is selected, the active area. correction will be applied. The default is true which will apply the correction.

Type boolean
Default TRUE
Close Window