Two strategies for acoustic localization in air using a compact sensor

Two complementary methods for acoustic localization of an airborne sound source using a pair of microphones will be described. One approach develops a real‐time solution by applying a dual time delay to the microphone outputs to form two oppositely directed cardioid beam patterns. The ratio of the difference to the sum of the cardioid signals determines the azimuthal location of the source. The second approach, which is slower, but more discriminating, uses a cross‐correlation routine to find the relative time delay between the two microphone outputs. The characteristics of both methods were tested in an anechoic chamber using a synthesized helicopter signal and the helicopter signal plus an independently located white noise source. [Work supported by the Office of Naval Research.]