Measurement preprocessing for nonlinear target tracking

When measurements are available in the polar or spherical co-ordinate system the tracking algorithm becomes nonlinear. The authors consider the problem of tracking a target moving at a constant velocity in a straight-line trajectory when the measurements are available in polar co-ordinates. A new algorithm involving co-ordinate transformation, linearisation and approximation is presented. The transformed measurements are preprocessed and sent to a Kalman filter which yields the final state estimates. Simulation results are presented to demonstrate the superior performance of the new algorithm for the nonlinear problem