To retain the RPC information for ASTER datasets, you will need to do the following *before* layer stacking the datasets: - open the ASTER 1A or 1B dataset - close all other datasets but the first VNIR bands - Go to Edit Header ->Edit Attributes ->RPC/RSM Emulation - Toggle on RPC emulation - Close the header dialog Now, the ASTER VNIR bands should have RPC information in the Map Info. Save this file to a new, ENVI format file. - Close the original ASTER VNIR dataset and reopen. - this time close all datasets but the SWIR bands - again, toggle on the RPC emulation. You must do this for every dataset because the RPCs need to be regenerated for the different datasets since they have different spatial resolutions. - Save the SWIR bands to an ENVI format file. Now you should have the ASTER VNIR bands (15m resolution) and the ASTER SWIR bands (30m resolution) saved to ENVI format files which both have 'RPC Geographic Lat/Lon' as their projection. These can then be layer stacked. However, I would still suggest that you orthorectify the images first before layer stacking them and then running FLAASH. You should be able to get around the 'non-blank pixels' problem by increasing the tile size in the FLAASH advanced parameters.

Hi ! ... MariM, it is necessary to do this with VNIR and SWIR bands?, when you open ASTER L1A and L1B images in ENVI, and you orthorectify, ENVI automatically reads the RPCs from image, may be I understand wrong, if you do the steps you suggest, then you can Layer Stacking and almost will mantain RPCs information? What if I have a ASTER GeoTiff image that don't hace RPC's ? Jose Lattus