MTRDR vs TRDR vs TER

[Rochdi]

Hello There,

Just to make sure and to erase any doubts I have about the calibrated CRISM directories:

TRDR: this CRISM contains hyperspectral targeted observations converted to units of radiance (I/F), divided into two spectral cubes VNIR (s) and IR (L).

TER: this CRISM directory includes I/F hyperspectral targeted observations with a full spectral range (VNIR-IR), this directory has been corrected for geometric, photometric, atmospheric, and intrumental effects.

MTRDR: Map-projected version of TER directory.

Currently, I'm using TRDR directory in my research but I'm still wondering about the most recommended directory for mineral detection.

Look forward to your reply,

Rochdi Khalid

 

[Ray Arvidson]

The best data set to use is the MTRDR, if this product exists for your scene. Next best is the TER, which you can map project using CAT, again if it exists for your scene. Next is the TRDR data set. You have the correct descriptions.

Ray Arvidson

[Rochdi]

Thanks a lot, Now I'm totally sure about it.

Please, I still have one question, is it necessary to flatten result after I do a band math? and what is used for?

[Ray Arvidson]

Flatten is used to reduced column to column variations in sensor space TRDRs. The TERs have already been flattened.

Ray

[Rochdi]

Thanks a lot, Sir.
I still have another question, I used ENVI band math to calculate a certain index, the output shows a signle monochrome image as seen below.
By using the mentioned output, I want to display the spectral profile of the bright areas, but the "spectral profile" icon in the ENVI toolbar is disabled, it gives only three options: arbitrary profile, horizental profile, and vertical profile.

Does it occur because the displayed output is one monochrome band? if it's so, how can I fix this, please?

Your help is much appreciated,

Rochdi.

 

 

[Ray Arvidson]

You cannot do a spectrum from a monochrome image. Overlay the spectral index map over the TRDR data. Then select the TRDR data on the ENVI vertical toolbar and then you can see the spectra for bright areas in the spectral index map,  if you move the cursor the the bright pixels in the spectral index map.

Ray

[Rochdi]

Thanks a lot, Ray. But I came up with this instead, I chose to create two views, one for the preprocessed TRDR data, and other for the spectral index map. Then, I link them together as seen below.
Now, I can see the spectral profile of each pixel I clicked on.

[Rochdi]

Hello Ray,

I'm looking for DEM of the scene above. Is PDS Geosciences Node Data provide Digital Elevation Models of CRISM data? 

Your help is much appreciated,

Rochdi.

 

[Ray Arvidson]

The DDR has elevation data from MOLA observations. In sensor space so just project the DDR using CAT and use the projected MOLA elevation plane. Otherwise no special DEMs for CRISM data.

Ray