An FPGA-based data acquisition system for a 95 GHz W-band radar

We describe a 95 GHz radar for an unmanned aerial vehicle (UAV). The radar measures vertical profiles of the reflectivity and Doppler velocity of clouds, which are then telemetered to the ground for storage. Telemetry bandwidth requires that substantial real-time data processing be done on the UAV in a low-power (less than 100 watts) and small size (less than 1 cubic foot) system. A prototype was developed in less than a year, thus a flexible programmable technology was required. Although typical remote sensing radars use DSP chips, it was determined that our power, size, performance and design-time requirements were best met using FPGA technology. Our system is based on the Giga-Ops Spectrum system which uses Xilinx FPGAs on a novel modular PCI board. Unlike numerous recent FPGA-based signal processors, this presents a new class of applications and embedded system requirements. Reconfigurable capabilities are currently being explored to support radar algorithms which can adapt to a changing environment.