Estimating source position accuracy of a large-aperture hydrophone array for bioacoustics

A linear error propagation analysis was applied to a hydrophone array used to locate sperm whales [see Møhl et al., J. Acoust. Soc. Am. 107, 638–648 (2000)]. The accuracy of two-dimensional (2D) and three-dimensional (3D) array configurations was investigated. The precision in source location was estimated as a function of inaccuracies in measurements of sound velocity, time-of-arrival differences (TOADs), and receiver positions. The magnitude of additional errors caused by geometric simplification was also assessed. The receiver position uncertainty had the largest impact on the precision of source location. A supplementary vertical linear array consisting of three receivers gave information on the vertical bearing and distance to the sound sources. The TOAD data from an additional receiver as well as from surface reflections were used to form an overdetermined location system. This system rendered positions within two standard deviations of the estimated errors from the original 3D array.