Moving Target Recognition from a Low-SWaP Airborne Radar System

Multi-Domain Operations (MDO) require the use of Unmanned Aerial Systems (UAS) for autonomous collection of Intelligence, Surveillance, and Reconnaissance (ISR). Electro-Optical Infrared (EO/IR) can provide recognition of moving targets, but their operability is limited by darkness and degraded visual environments (DVEs) such as clouds, smoke, dust, fog, and haze. Radar systems provide all-weather ISR capability and are capable of identifying static targets, but they are typically not capable of producing imagery of moving targets in high-enough resolution to support target recognition. To address the warfighter’s need for responsive target location and recognition, IMSAR LLC is proposing to leverage its low-SWaP high-performance radar systems to process high-resolution SAR imagery to detect, geolocate, image, and recognize moving targets Detection, identification, and tracking of moving objects in SAR signals is necessary in both civil and military applications. However, SAR processing assumes the ground is static, and moving targets can cause errors in SAR images, such as defocusing and target displacement. Radars use Moving Target Indication (MTI) mode to detect moving targets. To reliably image moving ground targets for ATR, the target position and attitude must be known to a higher degree of accuracy than what a single radar can provide. Also, radar geolocation accuracy from MTI is highly range dependent in the cross-range dimension, as radar angle accuracy is usually 1-2 orders of magnitude higher in angle variance than an EO/IR sensor.  During Phase I, IMSAR successfully performed advanced methods of SAR data collection using two radars simultaneously collecting data on moving targets. Using post-processing techniques with truth data, the SAR data was used to accurately determine the location and velocity of moving targets. By constraining the target’s path and taking a directional derivative across a Digital Elevation Map (DEM) slope, IMSAR will estimate the combined pitch/roll needed to estimate the moving target’s orientation. For Phase II, IMSAR will partner with Atmospheric and Environmental Research (AER), who will further develop MTR algorithms for target recognition.