A method of processing incoming signals, such as RF signals, includes receiving the incoming RF signals at two (or more) spatially-separated receivers, then processing the signals to determine a phase lag between the two signals. This allows a presumed location of the signal source to be determined, based on the time difference of arrival (TDOA) of signals at the separated receivers. This can be used to produce a phase adjustment of one of the signals, allowing the signals to be coherently summed. The coherently summed combined signal is then examined for instances where a threshold magnitude is exceeded. This information is then used to create a blanking mask, which is then employed as a filter to incoming signals, to blank out non-coherent signals, such as noise and extraneous signals from sources that are not of interest. The blanked signal train is then examined/analyzed for constant pulse repetitions.