Signal-selective time-difference-of-arrival estimation for passive location of man-made signal sources in highly corruptive environments. I. Theory and method

For the problem of estimating time difference of arrival (TDOA) of radio waves impinging on a pair of antennas for the purpose of passively locating the source of a communications or telemetry signal in the presence of interfering signals and noise, a new class of signal-selective algorithms that are highly tolerant to interference and noise is introduced. Unlike conventional methods, the new methods cross correlate frequency-shifted as well as time-shifted versions of the received data in order to exploit the unique cyclostationarity property of the signal of interest