Digital elevation model generation using ascending and descending ERS-1/ERS-2 tandem data

In this study we show how ascending and descending ERS-1/ERS-2 tandem data can be used to generate a precise digital elevation model (DEM). In particu lar we present the advantages, for DEM generation, of combining ascending a nd descending interferometric data pairs with large baselines; unwrapping p roblems caused by the high fringe rates of these data are minimized by appl ying a flattening technique based on the use of a data pair with smaller ba seline. The presented experiments carried out on the data of an area with s teep topography (Etna volcano, Italy) confirm the potentiality of the propo sed technique.