Digital coherent processing to enhance moving targets detection in a navigation radar

Abstract

This paper demonstrates a method for doing coherent processing on navigation radar data. The radar transmit and receive signals are connected to a separate frequency conversion unit which transfers the X-band signals to an IF. These signals are digitized in two coherent channels and processed together. The system has been tested in field trials where pulse-Doppler operation against real targets, such as vehicles was demonstrated. Also measurements on synthetic targets with known Dopplers and ranges generated with the Digital RF Memory (DRFM) system EKKO II were conducted. Additionally a real-time processor has been developed. It is based on a board with analog-to-digital converters (ADC) and field programmable gate arrays (FPGA) and a computer with a graphical processing unit (GPU). Pulse compression and Hilbert transform are implemented in the FPGA while Doppler processing and CFAR are done in the GPU. An experiment demonstrating real-time moving target detection with this hardware has been conducted.