A challenging task in Over-The-Horizon Radar (OTHR) is the tracking of target altitude. It has been shown that the micro-multi-paths due to ocean/ground reflections may reveal important information about the elevation maneuvering of a target. The Doppler signature of such micro-multipath signals is typically composed of three components having close nonlinear time-frequency behaviors. In this paper, the authors develop novel time-frequency analysis techniques for the characterization of Doppler effect of micro-multipath signals. The proposed method is based on the local analysis of the signal phase, followed by a stationarization operator.