Characterisation Studies of Underwater Target Tracking

Passive target tracking using bearings-only measurements is used to track underwater targets. Unscented Kalman Filter (UKF) is proved to be efficient non-linear estimator to estimate the target motion parameters. An effort is made to find out the Range Uncertainty Ellipse Zone (RUEZ) of the target using UKF covariance matrix in Monte-Carlo simulation. Underwater warfare today constitutes one of the greatest threats to the freedom of the seas. In under water, a single submarine processes noisy sonar bearings from a radiating target (ship/submarine/torpedo) in passive listening mode. The target is assumed to be at constant velocity. Bearing measurements by passive sensors are inaccurate. The observer processes these measurements and finds out Target Motion Parameters (TMP) - viz., range, course, bearing and speed of the target. This process is called Target Motion Analysis (TMA). Here the measurement is non-linear, making the whole process non-linear. Once the target’s RUEZ becomes less than that of homing zone of the weapon to be fired on to target, weapon can be released to destroy the target.