The Beacon Locator Project: A Passive Direction Finding System for Locating Pulsed Emitter Signals

RF emitters can be tracked through their electromagnetic energy transmissions by passive direction finding systems. These systems have many applications, including aircraft tracking, radio navigation and emergency aid. MIT Lincoln Laboratory had an interest in developing such a system for an airborne platform. In order to analyze potential designs, we simulated three direction finding methods, time difference of arrival (TDOA), phase difference, and amplitude comparison, in MATLAB and compared the accuracy of their direction calculations. The amplitude comparison method was found to be both relatively accurate and practical to implement. For this reason, the amplitude comparison method was implemented in an FPGA based development module as a proof of concept