ABSTRACT
The motion estimation problem of undersea objects utilizing acoustical measurements is a difficult but important problem as evidenced by the numerous papers. The first objective is a characterization in a coordinate system of the constant velocity contact motion model and the variety of measurement models. In choosing a coordinate system, it has been found that it is better to formulate the problem so that the observations are linearly related to the states of the contact. In passive tracking, the following systems have been used presuming a nominally constant velocity source. The type of measurements made on the contact, for the purpose of determining its motion, influence the selection of the coordinate system representation. Varied approaches to linear filtering theory as applied to contact tracking have been introduced. Typically, the tracking problem is nonlinear and requires linearization. The linearization procedures influence differently the estimator quality from that using recursive processing of measurement data, that is, Kalman filtering.
