User Manual - pancroma

PANCROMA TM allows three, four and five endmember analyses for Landsatdata. (Note that five-endmember analysis requires disk scratch files so certainparts of the computation may take considerably longer as stored data isrecovered from disk). There may be more or less cover types in the image and allof the types may not be identified. Future releases will allow a greater range ofendmember types but identification of the endmembers will still be an issue.As with any multispectral analysis method the model may not always matchreality and there are lots of provisos to consider for the method. The mostobvious is how to determine the number and type of endmembers in the scene.Also, In order to get good results, the library spectra must be calibrated to thesatellite sensor. This can be done by taking ground readings with aspectrophotometer or other means.It is perfectly legitimate to compute negative abundances from a mathematicalstandpoint. This can sometimes occur for a variety of reasons. Unfortunately271