Monitoring of Urban Environments with TerraSAR-X Data

Abstract

The actual process of rapid urbanisation is associated with various ecological, social and economic changes in both the urban area and the adjacent natural environment. To keep up with the effects and impacts of this development, effective urban and regional planning requires accurate and up-to-date information on the urban dynamics. Recent studies have proven the applicability of high resolution optical satellite data for the acquisition of some of the requisite spatial and socio-economic information. Although radar data is more reliably available than optical imagery, high resolution radar imagery has barely been employed for urban applications so far. This fact is mainly due to a lack of civil space borne radar systems featuring a ground resolution which is suitable for the analysis of urban structures. Additionally significant difficulties concerning the interpretation of according data over highly structured urban areas occur. The german TerraSAR-X system will provide radar imagery with a spatial resolution comparable to actual high resolution optical platforms. This study investigates the potential use of high resolution radar data in the context of urban applications. Thereby a concept – that was developed on the basis of SAR data recorded by DLR’s airborne E-SAR system – will be adapted to an analysis of TerraSAR-X imagery. It introduces a temporally and spatially robust approach towards an automated analysis of the urban structure. For that purpose data sets of single-polarised X-band imagery are analysed by means of an object-oriented classification. This study includes the development of an improved image segmentation procedure in order to create meaningful spatial entities. Moreover, it contains the definition and application of a rule base for the detection of built-up areas, the derivation of the urban land cover and the generation of additional value-added information related to the urban structure.