First evaluations of Shuttle SIR-C and X-SAR data for landcover classifications

For the first time radar data in three frequencies (X-,C-,L-band) and in multipolarisation (HH, HV, VV, total power) are recorded simultaneously in orbit during the Shuttle Mission STS-59 in April 1994. The aim of this work is to improve land use classifications with X-SAR/SIR-C radar data. The data used are multitemporal X-SAR data (X-band) and SIR-C (C- and L-band) data of April 11, 1994. As a first step, the data were coregistered. From this data set three different band combinations were selected: multitemporal X-Band data, multipolarised C-and L-band of April 11 and a data set of the first two principal components of each frequency. All three sets were classified using a maximum likelihood classifier. Finally, a fieldwise post-classification algorithm was applied based on the majority rule and the results were compared with a digital ground truth map in a two-dimensional accuracy matrix. For a complete and exact assessment of the landuse classification capabilities the acquisition date was unfavourable due to the limited number of agricultural crops at that time. Only winter-cereals and rape seed had already emerged. However, vegetation cover on these fields ranged from approximately only 20% up to 80%.