SToRM SAR, a Multi-static Precipitation Radar Hosted by Micro-satellites: an Update on Ground-based Risk-Reduction Field-test Results and Airborne Demonstration Plans

SToRM SAR is an approach developed by BAE Systems and Colorado State University for a space-based 3D multi-static precipitation radar that employs agile micro-satellites operating synchronously in formation to provide 1km horizontal spatial resolution observations of a precipitation field using a new multi-static tomographic method. Observations at this horizontal resolution are needed to resolve the fine thermodynamic phase structure present in many severe storms, and to support the weather process research needed for future convection-resolving weather models. The primary focus of the proposed work is on next-generation space-based precipitation field observations at finer spatial scales typically exhibited by severe storms.

SToRM SAR (Satellite Tomography of Rain and Motion using Synthetic Aperture Radar) directly leverages the rapid developments in small satellite technology and launch capability to provide significant new capability at a mission cost more than 10x lower than other space-borne precipitation radars- with the ability to penetrate and characterize severe mid-latitude storms at the 1-km scale from space for the first time. The approach is compatible with both X-band and Ku-band operation, enabling full profiling through intense storms using transmitter power levels consistent with miniature solid state RF amplifiers. The along-track spatial structure is observed using a scene illumination approach similar that used for the spotlight-mode employed on traditional 2D SAR, but with important modifications to observe the diffuse and dynamic precipitation field.

Under a 3+ year IIP, the overall mission and instrumentation risks have been reduced though detailed observing concept and instrument payload design, supported by realistic simulations of the complex 3D precipitation field observations, and ground-based coherent radar field demonstrations using the CHILL precipitation radar research facility at Colorado State University. An airborne demonstration of the SToRM bi-static observation method is under development is planned for the summer of 2024.