Passive geolocation in underwater environment

The measurement of an emitter´s position using electronic support passive sensors is termed passive geolocation. The emitting target could be in underwater environment. In this paper, we propose a Time Difference of Arrival (TDoA) algorithm for passive geolocation in underwater environment. In underwater environment, we apply a modified UWB Saleh-Valenzuela (S-V) model to characterize the underwater acoustic fading channel. To estimate the delay for TDoA of two correlated channels, we propose an TDoA finding algorithm, and compare with existing approach. Simulation results show that our TDoA algorithm performs much better than the cross-correlation-based TDoA algorithm with a lower level of magnitude in terms of average TDoA error and Root-Mean-Square-Error (RMSE). In underwater environment, the performance in rich scattering underwater environment is worse than that in less scattering underwater environment, because the latter has less clusters and rays, which would cause less uncertainties in TDoA.