Radar Interferometry with Public Domain Tools

The development of public-domain software in the scientific community has stimulated a fast and free dissemination of ideas. Here we present latest contributions to public-domain radar interferometry software to create interferometric products and to analyze and visualize these products. We present the feasibility of the Doris radar interferometric software of Delft University of Technology to create ENVISAT interferometric products such as DEMs and deformation maps. A stepwise description of the creation of an ENVISAT DEM of the Las Vegas area is presented, using besides Doris the ESA BEAM toolbox, the statistical cost phase unwrapper SNAPHU (Stanford University), the Generic Mapping Tools (University of Hawaii), and the PROJ.4 package (USGS). Finally, the GRASS GIS software is used to drape a LandSAT image on top of the computed DEM in order to show the analysis and visualization capabilities of this free GIS package. These packages are also described briefly in this paper. Both advantages as well as drawbacks of these tools are discussed. It is the intention of this paper to demonstrate how a larger scientific community can benefit from freely available tools, and which contributions need to be solicited for.