Question #4028

Radiometric calibration for Galileo images: gllssical

Added by Ashley Carlton over 2 years ago. Updated about 1 year ago.

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I am interested in applying the radiometric calibration to Galileo images. From my understanding, the calibration removes the dark current. However, I don't want the units of reflectance (I/F) or radiance. I am interested in getting the energy deposited per pixel. It is easy enough to find this using the DN and the gain, but I'm not sure how to get this from the radiance.

Many thanks in advance for your assistance!


#1 Updated by Tammy Becker over 2 years ago

  • Status changed from New to Acknowledged

#2 Updated by Moses Milazzo over 2 years ago

Hello Ashley,

The gllssi calibration program does indeed remove the dark current and it also applies the rest of the radiometric calibration. Radiance units ( Watts/m2/sr) are the value you want the calibration to output if you are looking for energy. You'll then need to multiply the output values of gllssical by 10,000 (because gllssical calculates milliwatts); by the exposure time—with or without a small shutter offset correction—(this should be in the cube labels); by the area of the pixel at the surface (this will be the resolution—m/px—in the label); and by 2Pi (to account for the angle of emittance from the surface).

This will give you Joules/pixel.

#3 Updated by Tammy Becker over 2 years ago

  • Status changed from Acknowledged to In Progress
  • Assignee set to Moses Milazzo

#4 Updated by Tammy Becker over 1 year ago

  • Status changed from In Progress to Resolved

#5 Updated by Moses Milazzo about 1 year ago

Hi Ashley,

Did my instructions help? Can we close this issue?

#6 Updated by Stuart Sides about 1 year ago

  • Status changed from Resolved to Closed

Closed for author

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