A new approach for Doppler-only target tracking

The paper addresses the problem of estimating position and velocity of a moving target given Doppler-shift measurements from multiple sensors located at different places. First, observability of a constant velocity motion from a single Doppler sensor is studied and an observability decomposition is introduced. Then, based on such a decomposition, a novel dual-stage filter for centralized multisensor Doppler-only tracking is proposed. In the first stage, a bank of local filters, operating in the observability decomposition coordinates, estimate, for each Doppler sensor, the relative observable state. Next, in the second stage all estimates from the local filters are fused in order to estimate the overall target kinematic state. In order to overcome the well known difficulties of Doppler-only tracking in the case of imprecise prior knowledge on the initial target position, a suitable multihypothesis initialization procedure is adopted. Performance of the proposed dual-stage filter is evaluated via simulation experiments.