Beamforming using phased arrays of microphones is a popular technique for noise source imaging in certain applications in aerospace. Scale models tests of airframe noise, for example use the method extensively because the acoustic source distribution is complicated and matches the assumptions of the algorithm. Beamforming can be done in the frequency domain or the time domain. The time domain version adapts easily to moving sources including aircraft flyover and ground vehicle pass-by tests. Frequency domain formulations have been extended to in many ways. Recent versions improve resolution by deconvolution and treat extended, coherent sources seen, for example, in aircraft engine tests.