CRISM Radiance to IoF

[Rochdi]

Hello There,

Should I do "Radiance to IoF" before I convert the PDS CRISM data to CAT?
I'm asking this question because I want to analyze the spectral profile of a mineral on Ritchey crater using CRISM L cube data, but I noticed the Y axis missed "I/F" as highilighted in your docs. The graph axes are the following:

-> X axis: Data Value

-> Y axis: Wavelength (um)

Do I really need to apply "Radiance to IoF" first? is this like a "Radiometric Correction" to PDS CRISM data?

I used to do this, but an error has occurred said: "The input data is not a radiance"

Your help is much appreciated.

[Ray Arvidson]

Hi: If you use the data that have IF in their label then no need to convert from radiance to IF. This has already been done for you. The files with RAD in their names do need to be converted. Use the IF files, please. When we developed the archives we wanted to supply an IF file and a RAD file for a given scene. The IF file has been converted from radiance to I/F and denoised. The RAD files have just been converted from raw data to radiance values. Please read the Software Interface Specification Document (https://pds-geosciences.wustl.edu/mro/mro-m-crism-2-edr-v1/mrocr_0001/document/crism_dpsis.pdf) for details.

Ray Arvidson

Node Manager and CRISM Team Member.

[Rochdi]

Hi Ray: the data I'm using includes IF in their label (frt0000a0b7_07_if164l_trr3 | frt0000a0b7_07_if164s_trr3). So, there's no need to convert them to IF.
But is it okay to see "data_value" in Y axis instead of "I/F" while I display the spectral profile?

Thanks.

[Ray Arvidson]

Yes, it is normal. You can rename the axis title once the plot is displayed.

Ray

[Rochdi]

Hi Ray: Thanks a lot, that's what I did.