Novel way of vector miss distance parameters estimation based on frequency difference of arrival

A new approach based on the frequency difference of arrival under long baseline conditions is proposed for estimating the vector miss distance parameters of a target. The direct identification of the constant velocity trajectory model from the Doppler signal requires a 6-dimentional nonlinear optimization. The iterative process of this optimization is complex comparatively, and the results are severely limited by the selection of optimal initial value. Taking full advantage of the continuous motion character of the target, the process is partitioned into several steps. Within these steps, locale pseudo-linear models based on integrated Doppler and location from range-difference measurements are used to get the estimated values. Meanwhile, the estimated values, regarded as the initial values of the nonlinear process, can obtain effective results faster and accurately. Simulation results demonstrate the effectiveness and feasibility of the proposed method.