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This paper describes the relationship of matched field processing (MFP) and multipath delay localization (MDL). MDL is a simplification of MFP. Methods to analyse multipath structure, especially the time range plot, in the deep ocean are presented. The coincidence between theory prediction and experiment data shows that the methods and programs could be used to determine multipath time delay structure. A realistic method called the L/sub 2/ norm match algorithm for MDL is developed. The depth-range ambiguous figures are satisfactory. Comparing the match methods of absolute delay and relative delay shows that the latter is better than the former. In the case of known source depth a doublepath match plan is given. We can immediately determine the source distance from range-delay curves. The influence of inexact ocean environment parameters and receiver configuration on doublepath ranging is analysed.

Electromagnetic time reversal (EMTR) has emerged as a promising technique to locate disturbances in power grids, thanks to its location accuracy and robustness against parameters uncertainties. Furthermore, in a reflective medium, like the one of a power network, it has been shown that the method requires no more than one single observation point. In this paper, we present an experimental validation of EMTR to locate disturbances in real power networks. The validation is performed on a full-scale unenergized 677-m-long, double-circuit 10-kV overhead distribution line. The disturbance is emulated by a voltage pulse injected between one of the line conductors and the ground using a high-voltage pulse generator. The frequency spectrum of the injected voltage pulse is specified such that the originated electromagnetic transients are compatible with those of power line faults, lightning, and conducted intentional electromagnetic interferences. The transient currents generated by the emulated disturbance are measured at one end of the line, considering two different line configurations. According to the EMTR technique, the measured signals are time reversed and back injected into the system that, in our case, is a simulated model of the considered distribution line. More specifically, it is represented by a constant-parameter line model implemented within the EMTP-RV simulation environment. For both cases, the disturbance is accurately located, and the phase of the circuit at which the pulse was injected is also identified.