A 9-Channel Phase Coherent Receive System for Direction of Arrival Estimation

Collapsed buildings are a common occurrence after earthquakes, but are also commonly caused by gas explosions. The survival chance of buried victims is heavily dependent on the time it takes to locate and rescue them. This paper introduces a 9-channel phase coherent receive system intended for direction finding in search and rescue applications. The motivation for this system is to minimize the time necessary to locate the buried phones of victims. The design consists of an FPGA based digital system with high speed I/O for data acquisition and signal processing, as well as nine synchronized receivers each covering the entire target bandwidth. A high phase resolution is achieved down to very low input levels.