Radar spatial considerations for land cover extraction

One of the more recent developments in operational space-borne remote sensing is the availability of radar. A disadvantage of currently available space-borne radar is that data are almost entirely single wavelength and single polarization, limiting the ability to do traditional digital classification. Frequently radar-derived values such as texture and combinations of these radar-derived values with the original radar or optical data can improve digital classification accuracies. Various radar spatial components including texture, texture window size, speckle reduction and post-classification filtering can have significant impact on classification. This study examined these various spatial components of space-borne radar for feature identification in two sites in East Africa and one in Nepal. Relative accuracy of the resultant classifications was established by digital integration and comparison to ground reference information derived from field visitation. The extraction and use of these techniques, particularly texture, were found to be advantageous. There were, however, differences from site to site as to which technique was most effective.