Producing a Digital Elevation Model Using a Cluster of Small-Aperture SAR Satellites: An Airborne Demonstration

Abstract:
The generation of time series of digital elevation models (DEMs) is fundamental for monitoring and understanding fast dynamic processes on the Earth’s surface. This work presents a novel concept for single-pass DEM generation based on a cluster of small-aperture synthetic aperture radar (SAR) satellites with different along- and cross-track baselines operating with a sub-Nyquist pulse repetition frequency. A key feature of the concept is the height retrieval algorithm based on a generalized maximum likelihood estimation, whose theoretical formulation is presented. A demonstration is then conducted using multi-baseline airborne data from DLR’s F-SAR system. The first results show that the proposed concept is a promising solution for the generation of highly accurate DEMs robust to phase unwrapping errors in a single pass.