Swarm Radar Surveyor for Space Based Environmental Monitoring

GeoOptics is advancing space radar on two fronts: advanced instrumentation combining all radar signal generation and processing in a tiny module, and system architectures comprising swarms of cooperating “cells” to provide new observation types and unrivaled performance. Formerly complex platforms become coordinated swarms of low-cost cells exploiting the power of linked networks to yield vastly increased observational power. The Swarm Radar Surveyor (SRS) will offer high-resolution, multistatic SAR imaging, onboard InSAR processing, Jason-class altimetry, and advanced scatterometry, operating concurrently. This is done with cubesat-class cells flying a novel Radar-On-Module for Earth Observation (ROMEO). SBEM data gaps addressed include:• Tropical cyclone intensity• Ocean surface vector winds• Soil moisture• Snow depth• Sea ice characterization. An operational SRS swarm would feature:• Vehicle separations of 2-400 km• Two radar frequencies: 13.5 & 5.4 GHz• Pseudonoise (PN) modulation of the radar signals at up to 300-Mb/s• Instantaneous electronic beam steering A core idea behind SRS is to harness the “network effect” in which the utility of a linked system grows far faster than the number of nodes, typically as N2, while costs, owing to mass-replication, miniaturization and system-level redundancy, plummet. Under ONR funding, GeoOptics has developed a radar system architecture called Cellular Orbiting Altimetry/Scatterometry Technology (COAST). SRS will enhance COAST Alt/Scat while adding powerful mono- and bistatic SAR/InSAR imaging functions. Through the network effect, a swarm of 4 cells will offer, among other benefits, 44 mutually compatible observations:• 8 forward-scatter SAR images• 8 back-scatter SAR images• 4 nadir altimetry measurements• 12 bistatic altimetry measurements• 12 bistatic scatterometry delay-Doppler maps The SRS concept advances the current art for space radar systems in several ways:• A more versatile, compact, low-cost radar signal generator and processor• A substantially smaller, low-cost multi-function spacecraft bus• Use of the network effect with swarms to increase observing power and value• Use of PN-coded signals for versatility and to enable smaller SAR antennas• Combining mono- and bistatic/multistatic radar observation• Combining SAR, altimetry and scatterometry observations• Dramatic reduction in system cost Quantitative examples of advances offered by the SRS swarm concept include:• Altimetry surface resolution improvement by 30x over Jason-class missions• Scatterometry surface resolution improvement by 50x over single scatterometers• Multiple forms of SAR imaging and sensitive InSAR motion sensing & topography• Wind direction improvement by >10x thru concurrent viewing from multiple angles• Cost reduction per vehicle of >50x compared with current flagship radar missions