A two-dimensional Kalman tracking filter is described for obtaining optimum estimates of position, velocity and acceleration of an aircraft whose acceleration is perturbed due to manoeuvres and/or other random factors. In a track-while-scan operation, a two-dimensional radar sensor is assumed to measure the range and bearing of the vehicle at uniform sampling intervals of time T seconds through random noise. The steady-state gain characteristics of the filter have been analytically obtained and the computer results are presented.