Comparative digital analysis of Seasat-SAR and Landsat-TM data for Iceland

Abstract

In the past, data available from the microwave range of the spectrum have been recognized as being of high potential for many geoscientific applications. Within our former investigations it was demonstrated that the digital combination of data from different spectral ranges offers particular extended possibilities for geoscientific applications. Our study was carried out using digitally recorded Seasat-SAR and Landsat-MSS and -TM data of test areas in Southern Iceland, in order to demonstrate their complementary character and information content, as well as the benefits of the digital combination of both data sets. The results and experiences gathered during the realization of this investigation show that, for a successful application of remote sensing data in complex areas like Iceland, complementary data sets are an indispensable interpretation tool. This can be justified in terms of the supplementary information content of optical and active microwave data: object specific reflection and emission including structural features in the optical domain; surface roughness and soil moisture in combination with morphological elements within the radar data. During the investigation it became obvious that, in many cases, the understanding of an individual dataset can be improved significantly by the availablility of additional data from a different part of the spectrum. Fundamental requirements for a successful application of both data sets are: the availability of radargrammetric correct data; the application of appropriate image-processing techniques, such as the I-H-S transform for an optimized combination of data sets.