Simulation of SAR Images and Radar Coding of Georeferenced Information for Temperate Glacier Monitoring

Synthetic Aperture Radar (SAR) interferometry has the potential to measure temperate glacier displacement with a very high precision compared to terrestrial sparse ground measurements. But the strong topography of mountainous areas where most alpin glaciers are located makes the use of SAR images rather difficult. Digital Terrain Model (DTM) are necessary to remove topographic fringes from interferograms and to geroreference the extracted information (radiometry, coherence, displacement field...). The georeferencing of SAR images is often performed by interferometric processing chains which do not allow the end–user to interact and to invert the process in order to code georeferenced information in the radar geometry. However, in a difficult context such as the processing of SAR data over alpin glaciers, it is very useful to be able to analyze the data and the processing results in both radar or in ground geometries. This paper presents a original method to perform this geometrical conversion task. The proposed approach is simple and straightforward to derive from a DTM visibility masks and simulated SAR images and to code any useful information in the radar geometry. Results are presented in the case of SAR images acquired by ERS (European Remote Sensing) satellites over several glaciers in the Mont-Blanc area.