Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Question regarding ENVI's Spectral Analyst
I am trying to learn to use Spectral analsyt and was wondering if you could please explain to me as to how to best get the endmembers from an unknown spectrum depending on the weighting as I couldn't find sufficient material for analysing the process and the results. These are some questions I had: 1. What type of weighting is required to run the analyst using SFF and another time using all three analysis types. 2. How do you choose the weighting. for all the three? is it best to use all the three. 3. What is the min and max when the weight is 0.[does that need to be channged or only the weight part] 4. What is the min and max when the weight is 1. 5. Does the reference spectrum have to match the unknown spectrum when the score is really high. 6. If there is a match between the reference and the unknown spectrum, does it mean that the unknown spectrum has that mineral of reference spectrum. Does the match mean anything interms of abundance or just identification? 7. Does the result vary when weighting for SFF is used and are there any limitations for SFF too. I would really appreciate any assistance in clarifying my doubts. Thanks coold