Abstract for presentation at The 13th Australasian Remote Sensing and Photogrammetry Conference

Three methods of extracting ASTER data from HDF files and processing are discussed on the basis of accuracy and ease of use.
Examples are presented of the effects of the crosstalk error in ASTER short wave infra red data (SWIR). The two available crosstalk correction routines were investigated but neither succeeded in eliminating all the crosstalk errors.
The lack of a routine to completely eliminate the crosstalk effect does not allow the true dark points for the SWIR data to be determined unless there is a large body of water in the image. A scene in which the true dark points could be determined was investigated in order to compare the difference in the SWIR mineral class ratios as determined when the true dark point was known with the ratios as determined assuming the true dark points were unknown.
The investigation showed that while correction for the dark points changes the values of the ratios, the mean values of the ratios and the shape of the histogram, the order of the ratio values is maintained and in percentage terms the change in the value of the ratios is minor compared with the change in corrected radiance. The distribution of the mineral groups remains the same and importantly the use of a dark point correction is not critical for determining mineral groups when SWIR band ratio methodology is used.