Experimental tests of a generalized acoustic triangulation method

A generalized acoustic triangulation method has been developed that takes into account the finite propagation speed of sound. The method has been tested using two 3‐microphone arrays separated by 1 km, together with a low‐flying commercial jet tracked via the Global Positioning System (GPS). The tests show that generalized triangulation is accurate as long as the bearing errors are small relative to the effective aperture of the two arrays. When the bearing errors are not small relative to the effective array aperture (e.g., at longer ranges), it is shown that significantly improved tracking accuracy can be obtained by assuming a constant speed target and using a bearings‐only solution instead of triangulation. Wind noise is shown to be the major source of bearing errors. The degradation of bearing and tracking accuracy due to wind noise is demonstrated using field data, and possible approaches for wind‐noise reduction are discussed. [Work supported by the U.S. Army Space and Missile Defense Command.]