Sonar localization using receiver beam profile features

A localization method for a sonar system equipped with an emitter and two receivers is presented in this paper. The signal reflected from the target is filtered through the receiver beam patterns whose knowledge is used to estimate the direction of the echo. Indeed, the known emitted signal and measurement of its travel time make it possible to compensate for distance and air absorption effects, and to calculate the ratio between the received echo and the original signal at all frequencies. Simulations with two beam patterns were conducted. A monotonic one over orientations was implemented, to show evidence that linearity reduces ambiguity: in this case, the method returns estimates with an error of less than 1.5° with SNR = 50 dB. If a bat´s beam pattern is adopted, most of orientations are estimated with an error less than 5°, even when SNR = 15 dB.