Target motion analysis using time delays measured from a nonlinear array

This study deals with underwater passive target motion analysis using wave front curvature techniques when time delay measurements are obtained from an imperfectly linear three-sensor array. It is shown that even with a very small array misalignment, relative ignorance about the true position of sensors or depth-elevation source angle can result in a very large bias on target range estimates. A non-time-recursive algorithm for estimating the position, speed, course, and depth-elevation angle of a target with constant velocity and depth is presented. The estimator is shown, by computer simulation, to be unbiased and statistically efficient