Shuttle Radar Topography Mission: DLR’s Interferometric SAR Processor for the Generation of a Global Digital Elevation Model

The Shuttle Radar Topography Mission (SRTM) will be launched in January 2000. Its intention is the global topographic mapping of the Earth’ surface. The data will be acquired by the first space-born single-pass synthetic aperture radar (SAR) interferometer. Within eleven days this mission will map all continents between 60latitude. The resulting data set is unique in two respects. Firstly, the height accuracy of about 6 m of the obtained Digital Elevation Model (DEM) and secondly the huge amount of data which have to be processed are remarkable. The global DEM generation requires an interferometric processing system that is highly optimized in respect to height accuracy and throughput and that is also working on an operational basis. DLR’s GENEric System for Interferometric SAR (GENESIS) was adapted to meet the mission requirements. This paper presents the architecture and algorithms of the implemented InSAR processor. The simulation of SRTM data is described and the expected SRTM-DEM characteristics are compared with ERS-1/2 data.