Estimation of aircraft altitude and altitude rate with over-the-horizon radar

In previous work, a matched-field estimate of aircraft altitude which uses multiple over-the-horizon radar dwells was presented. This approach exploited the altitude dependent structure of the micro-multipath rays which result from reflections local to the aircraft. While it was shown that the multi-dwell matched-field estimate is able to accurately estimate altitude while using typical radar parameters, the estimate was derived assuming that the aircraft altitude is constant for the duration of the track. In this paper, a matched-field method for jointly estimating altitude and altitude rate is presented which extends the micro-multipath model to include effects of constant altitude rate on the micro-multipath Doppler frequencies. Simulation results illustrate that altitude and altitude rate can be jointly estimated while achieving an altitude estimation accuracy of +/-2500 feet using 10 radar dwells.