ISIS 3 Application Documentation
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Radiometrically calibrates a Mars Exploration Rover (MER) Microscopic Imager(MI) image
Description
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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.
r = dn / fwhere: r is the corrected output value dn is the input pixel that has been dark current corrected f is a flat field pixel
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 |
Name | Description |
---|---|
CALSTAGE | The calibration stage to process |
Name | Description |
---|---|
CCDtemp | CCD temperature |
PCBtemp | PCB temperature |
RPCORRECTION | Correct for Referance Pixel |
ZECORRECTION | Correct for Zero Exposure |
AACORRECTION | Correct for Active Area |
An uncalibrated MER MI image.
Type | cube |
---|---|
File Mode | input |
Filter | *.cub *.CUB |
The resultant radiometrically calibrated cube
Type | cube |
---|---|
File Mode | output |
Pixel Type | real |
Filter | *.cub *.CUB |
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 |
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 |
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 |
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: |
|
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 |
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 |
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 |
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 |
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 |
Robert Sucharski | 2007-02-16 | Original version |
Christopher Combs | 2017-05-19 | 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. |
Jesse Mapel | 2019-05-15 | Now loads latest Mars satellites kernel because the planets kernel (de430) only provides Mars Barycenter. |