Passive Range-Difference Estimation in a Dispersive Medium

Passive source localization can be achieved by utilizing the range-difference (RD) measurements between the source and several spatially separated sensors. When the signal propagation medium is nondispersive, the RD is typically obtained from time-difference-of-arrival (TDOA) between sensor outputs. However, for a dispersive medium which corresponds to in-solid localization, the TDOA information is not reliable. In this correspondence, two RD estimation algorithms for dispersive medium are derived and analyzed, assuming that the dispersion curve is available. Computer simulations are included to contrast the estimation performance of the two methods with the Cramer-Rao lower bound (CRLB) for different conditions.