An approximate linearisation approach to bearings-only tracking

Abstract

Broadly speaking there are two classes of target motion analysis (TMA) algorithms for processing passive sonar bearings. The first contains highly sophisticated methods used for analysing a single contact of interest and typically these will involve careful probing to find the likely target dynamic model and detailed mapping of the uncertainties in that model's kinematic parameters. The second class consists of those methods suitable for keeping track of many hundreds of passive contacts within the area of interest to a submarine or surface ship C3 system. It is very much towards this latter application that this current algorithm is aimed. The basic form of the TMA scenario involves a constant velocity contact being tracked by a platform executing a series of manoeuvres which, for practical sonar reasons, usually take the form of straight-line constant-speed legs. It can be shown that, from considerations of the Fisher information matrix, the four kinematic states that fully describe the contact are not completely observable before own ship makes a manoeuvre and it is the strong influence that the motion of the sensor platform generally has on the kinematic information that can be extracted which gives bearings-only TMA its distinctive nature. (16 pages)