A Novel Technique to Generate Digital Elevation Models in a Single Pass Using a Cluster of Smallsats

Synthetic aperture radar (SAR) interferometry is an essential remote sensing technique with a wide range of applications. Studying and monitoring dynamic processes on the Earth’s surface requires digital elevation models (DEMs) at short time intervals, making distributed and multi-static SAR systems a very promising solution to this need. This work introduces a concept for distributed SAR interferometry using a cluster of smallsats with small antenna apertures operating with a pulse repetition frequency much smaller than the Doppler bandwidth and capable of single-pass DEM generation with high accuracy and robustness to phase unwrapping errors. The novelty of the proposed method is that the DEM is extracted from a tomogram formed using all available data without requiring as an intermediate step the formation of SAR images. This allows reducing the number of required satellites and obtaining increased baseline diversity at the same time. A cluster of smallsats is a very attractive low-cost solution for the implementation of future interferometric SAR missions.