In this paper, we investigate the detection of multi-path signal propagation in a Time Difference of Arrival (TDOA) localization scenario. Usually, TDOA measurements are obtained by determining the absolute maximum of the cross correlation function of signals recorded at different sensor nodes in a sensor network. Multipath signal propagation causes multiple peaks in the cross correlation function which lead to erroneous emitter localization. We use hypotheses of possible multipath signal propagation calculated from the autocorrelation functions to identify the line of sight (LOS) peak in the cross correlation function of a sensor pair.