Image Simulation and Processing for Time and Phase Synchronization in Spaceborne Distributed Synthetic Aperture Radar

Earth Observation is becoming increasingly crucial in our everyday lives, helping to monitor our planet’s health and the environment in general from a wide perspective. Spaceborne Synthetic Aperture Radar (SAR) is a key technology in this field thanks to its reliability and any-weather any-time nature. Recently the concepts of Multistatic and Distributed SAR (DSAR) have been introduced with the aim of improving the products of a monostatic system and of making system realizations feasible by microsatellite, nanosatellite and CubeSats. A critical aspect that can affect DSAR performance is the lack of time and phase synchronization. The problem can be tackled at the level of image processing but representative training data are necessary for algorithm development. In the framework of Space It Up, funded by the Italian Space Agency (ASI) and the Italian Ministry for Universities and Research (MUR), this paper presents a DSAR simulator able to generate realistic raw data including the most prominent error sources, i.e. lack of synchronization together with image noise, and navigation and pointing errors. The simulator is used as a test for algorithms addressing specific synchronization problems, like PRF reconstruction and oscillators’ offset compensation. Application to upcoming DSAR mission scenarios is shown in the paper.