Advanced ESM AOA and location techniques

The situation is considered in which a single aircraft must obtain passive angle of arrival and emitter location using its own sensors and on-board processing equipment. The majority of ESM systems in use measure azimuth AOA by amplitude comparison of signals received from antennas with different pointing angles. The authors examine the classic error sources for these systems and the advanced error-correction techniques that reduce the measurement errors of an amplitude comparison system tenfold or more. These techniques result in precise AOA measurement accuracies comparable with those previously achieved only with interferometer-based ESM systems. An advanced passive emitter location solution for a single platform having an ESM system that measures only azimuth AOA, frequency, and signal amplitude combines the best features and strengths of three passive ranging techniques to provide an immediate range estimate and subsequent precision location for radiating emitters