Vehicle motion parameter estimation using a wide- aperture acoustic sensor array of unknown shape

A nonlinear least-squares (LS) method is formulated to estimate the speed and the closest-point-of-approach (CPA) time and range of a ground vehicle whose broadband acoustic energy emissions are received by a ground-based wideaperture planar acoustic sensor array of unknown shape. It is assumed that the vehicle travels at a constant speed in a straight line. The three estimated motion parameters (speed, CPA time and CPA range) can be used to predict the variation with time of the vehicle range. Also, the proposed method can provide an estimate of the shape of the array if it is known on which side (left hand or right hand) the vehicle transits past the array. This passive technique is applied to real acoustic sensor data recorded during the passage of a variety of ground vehicles past a 10 m x 10 m planar cross array and its effectiveness verified by comparing the estimates with the actual values for both the vehicle motion parameters and the array sensor positions.