Introduction

Accurate surface topographic data is required to investigate a wide variety of geophysical processes. An exciting and promising technique for the application of remote sensing data has emerged in recent years: Interferometric SAR, also called INSAR.
Using SAR interferometry, it is possible to produce directly from SAR image data detailed and accurate three-dimensional relief maps of the Earth's surface.

In addition, an extension of the basic technique, known as differential interferometry, allows detection of very-small (in the order of centimetres) movement of land surface features. Both of these possibilities open up many new potential application areas of spaceborne SAR data in the areas of cartography, volcanology, crustal dynamics, and the monitoring of land subsidence.land subsidence.

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry