# Radiance in CRTM v2.4.0
**URL:** https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590
**Category:** CRTM
**Created:** [June 5, 2024, 5:29pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590 "2024-06-05T17:29:47Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Cas](https://forums.jcsda.org/u/Cas)
#### Post date: [June 5, 2024, 5:29pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590/1 "2024-06-05T17:29:47Z")
Hi, I’m just curious if there is an output for radiances in CRTM v2.4.0? I am using it with the python interface and running it with the “v.abi\_gr” sensor. It seems like the “Bt” variable outputs raw brightness temperatures on the order of 1000 K for these visible channels, and I am just curious if there is a radiance output instead, or an accurate way to convert from Kelvin to radiance units of mW m-2 sr-2 cm-1.
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### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [June 5, 2024, 8:32pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590/2 "2024-06-05T20:32:38Z")
Hi, Yes, RTSolution%Radiance (same structure as RTSolution%Brightness\_Temperature) outputs the radiance.
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### Author:  [@Cas](https://forums.jcsda.org/u/Cas)
#### Post date: [June 6, 2024, 6:26pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590/3 "2024-06-06T18:26:35Z")
Since I am using the python version, brightness temperature is called in the output as “crtmOb.Bt”. What is the variable I should call from crtmOb that is associated with the radiance? I tried both “crtmOb.rad” and “crtmOb.radiance” but those didn’t work.
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### Author:  [@BenjaminTJohnson](https://forums.jcsda.org/u/BenjaminTJohnson)
#### Post date: [June 7, 2024, 4:01pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590/4 "2024-06-07T16:01:13Z")
You should contact Bryan Karpowicz ([bryan.m.karpowicz@nasa.gov](mailto:bryan.m.karpowicz@nasa.gov)), he’s the author of the package. We’ll gladly accept any updates to the package via the github repository.
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### Author:  [@Cas](https://forums.jcsda.org/u/Cas)
#### Post date: [June 10, 2024, 7:29pm UTC](https://forums.jcsda.org/t/radiance-in-crtm-v2-4-0/590/5 "2024-06-10T19:29:07Z")
Thanks for directing me to Bryan, he was able to solve my problem. Just thought I’d post the solution here in case anyone in the future has the same question I had:
You must set “crtmOb.output\_tb\_flag = False” before running “crtmOb.runDirect()”, and then the crtmOb.Bt output will be in radiance units instead of in Kelvin.