Title: SRI CubeSat Imaging Radar for Earth Science (SRI-CIRES): Flight Demonstrations
Presenting Author: Lauren Wye
Organization: SRI International
Co-Author(s): Simon Lee, Patrick Rennich, Scott Williams, Rick Doe

Abstract:
Ground deformation measurements obtained with interferometric synthetic aperture radar (InSAR) technologies have the potential to improve short-term forecasting of natural hazards and enable more effective management of natural resources. For maximum impact, InSAR measurements must be precise (sub-cm level) and timely. Frequent acquisitions are needed to achieve both requirements. More observations per unit time provide enhanced deformation precision through averaging, and ensure that an event is properly captured and characterized. Yet, single-platform sensors cannot simultaneously achieve frequency and wide-area coverage, and traditional InSAR sensors are too expensive (> $300M) to replicate. SRI is working to provide high-precision ground deformation measurement capabilities in an affordable package ($1-2M) that can be used to form a constellation of InSAR sensors capable of rapid-repeat (daily) coverage of science targets. Such achievements are made possible through developments in nanosatellite technology, specifically the emergence of the CubeSat standard. Under a 2015-2016 ESTO ACT and 2017-2019 ESTO IIP grant, we have designed, developed, and tested an S-band radar instrument capable of moderate-resolution (5-25 m), high-fidelity InSAR performance (sub-cm deformation precision, SNR > 14 dB). The radar fits within 1.5U of a 6U CubeSat and satisfies the power and thermal requirements of the CubeSat environment. We call this subsystem the SRI CubeSat Imaging Radar for Earth Science (SRI-CIRES). We have advanced the SRI-CIRES RF and digital electronic subassemblies to achieve a functional flight-ready prototype (TRL 6). In this presentation, we review the initial flight test results of SRI-CIRES, showing that the prototype can meet the science objectives and performance requirements of an operational mission (e.g., can correct atmospheric artifacts and ionospheric effects to achieve sub-cm level accuracy).