TDOA-SDOA estimation with moving source and receivers

When there is a relative motion (rm) between a signal source and a receiver, the signal arrives at the receiver with a time-scaling. Under this condition, estimating the time-difference of-arrival (TDOA) of the signal at two receivers will have large errors, if the estimator ignores the effects of the rm. The correct approach estimates both the TDOA and scale-difference-of-arrival (SDOA) between the signals of the two receivers, via the maximization of the cross-ambiguity function (CAF). This paper first derives the bias of TDOA estimation under rm, when neglecting SDOA. It then gives a new, fast method, based on the Newton root finding algorithm, for determining the maximum of the CAF. Simulation results indicate that the TDOA and SDOA mean square errors attain the Cramer Rao lower bound.