Radiance in CRTM v2.4.0

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.

Hi, Yes, RTSolution%Radiance (same structure as RTSolution%Brightness_Temperature) outputs the radiance.

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.

You should contact Bryan Karpowicz (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.

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.