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ISIS Documentation

shadowcamcal

Calibrates ShadowCam Images

shadowcamcal performs radiometric corrections to images acquired by the Camera aboard the Korea Pathfinder Lunar Orbiter spacecraft.

The ShadowCam detector has a total of 3144 pixels, divided amongst 6 channels, each containing 524 pixels.

The ShadowCam camera has the ability to acquire images of differing sizes in line. The starting hardware detector pixel for the acquired image is specified by the ISIS label keyword, SampleFirstPixel. The first pixel in this detector is indicated by a value of ??(0 for LROC).

Bias Subtraction

Gain Correction/Normalization

Dark Subtraction

Flat Field

Flat Field

Radiance

IOF

Special Pixels

The calibration equation is: (update for SC) 

        reportedDN =
Where: 
        ObservedDN =

Categories

History

Victor Silva2024-05-22 Original version
Cordell Michaud2025-03-31 Refactored for better testability, simplified code where possible, and improved readability. Changed INTRCPTCOEFF parameter to INTERCEPTCOEFF for clarity and consistency.

Parameters

Files

This is the input cube that will be cropped.
Type cube
File Mode input
Filter *.cub

The smaller output cube containing the results of shadowcamcal.
Type cube
File Mode output
Filter *.cub

Write out calibration steps as cubes
Type boolean
Default False

Remove Bias Pixel columns in image Keeping in image will keep width of 524 pixesl per channel (6 total channels) Removing from image will reduce width to 512 samples per channel(6 total channels) Bias pixels total 12 per line, 8 blank/dark, 4 overscan (2 on each side of sensor channels)
Type boolean
Default True

Bias Average Subtraction

Mean or Median
Type boolean
Default True
Inclusions
  • BIASAVGTYPE

Type string
Default MEAN
Option List:
Option Brief Description
MEDIANMedian Use Median bias value for bias subtraction.
MEANMean Use Mean bias value for bias subtraction.

Gain Correction

Calibrate using the Gain Correction.
Type boolean
Default True
Inclusions
  • GAINFACTORS

Type filename
File Mode input
Default Path $kplo/calibration
Default $kplo/calibration/gain_factors.csv
Filter *.csv

Dark Subtraction

Calibrate using slope coefficients and intercept coefficients from respective csv files to compute dark level subtracted from image.
Type boolean
Default True
Inclusions
  • SLOPECOEFF
  • INTERCEPTCOEFF

Type filename
File Mode input
Default Path $kplo/calibration
Default $kplo/calibration/dark_subtract_slope.csv
Filter *.csv

Type filename
File Mode input
Default Path $kplo/calibration
Default $kplo/calibration/dark_subtract_intercept.csv
Filter *.csv

Flatfield Correction

Type boolean
Default True
Inclusions
  • FLATCOEFF

Type filename
File Mode input
Default Path $kplo/calibration
Default $kplo/calibration/flat_field.csv
Filter *.csv

Radiance Correction

Type boolean
Default True
Inclusions
  • RADCOEFF

Type filename
File Mode input
Default Path $kplo/calibration
Default $kplo/calibration/radiance.csv
Filter *.csv