Position Determination for Moving Transmitter Using Single Station

A common case in location problem is that the terminal is unstable or moving. The classical methods construct equations related to the measurements observed at the individual receivers first, and then solves the problem to localize the source. In this paper, we focus on the moving transmitter localization problem using only one station. The thinking of inverse synthesis aperture is implied, which takes advantage of the motion model to increase the equivalent aperture for higher accuracy. The proposed method formulates the problem through the angle of arrival and Doppler frequency measurements that are obtained from independent observations. After pseudo linearization by ignoring higher order noise terms, the estimator of position and velocity is easily solved through weighted least squares method. The bias reduction (BR) is utilized for lower bias and better root-mean-square error (RMSE). Using the result of BR as an initial solution, the maximum likelihood estimator (MLE) is realized through Gauss-Newton iteration. Theoretical analysis verifies that the BR estimator is efficient, which has Cramér-Rao Lower Bound (CRLB) accuracy if the noise level is mild. While MLE attends CRLB in higher noise situation albeit the possible divergence problem. Simulations indicate the feasibility and validate the advocated performance. The RMSE and bias match the theory very well.