Systems and methods for detecting, localizing, and filtering signals such as radiofrequency signals using an array of antennas are disclosed. Input signals each containing a signal of interested are received, along with a reference signal sharing one or more characteristics of the signal-of-interest. Predetermined time delays and frequency shifts are applied to the input signals such that the signal-of-interest components of the signals are synchronized and to cancel any Doppler-shifting between the signal-of-interest components. A filtering process is employed to filter the shifted input signals and sum them such that a metric indicating the degree of difference between the reference signal and the summed filtered signals (such as the mean squared error, for example) is minimized.