An advance warning system including an antenna pair and an RWR system to receive first, second and third signals for computing a frequency for all the signals and a phase difference between the signals. If the frequencies are within a threshold frequency difference and the phase difference is less than a threshold phase difference, two signals can be associated. If the frequencies are not within the threshold frequency difference, the RWR system generates a set of ambiguous angle of arrival AoA for the signals and correlates the two sets of ambiguous AoA to determine if there is a common AoA. If there is a common AoA, a third set of ambiguous angle of arrival AoA for a third signal is generated to determine if the three sets correlate. If there is a common AoA for all three signals, the three signals are associated.