1. A microwave system for examining an object comprising: (a) an array of antennas for radiating and receiving microwaves; (b) a microwave source connected to the array of antennas to provide microwave signals of a selected bandwidth to the antennas; (c) a receiver connected to the antennas to detect the microwave signals received by the antennas and provide signal data corresponding thereto; and (d) a computer connected to receive the signal data, the computer programmed to process the signal data to fowl a space-time vector of signal data from each antenna for a candidate location, to determine a test statistic for the candidate location as the ratio of the sample variances under the two hypotheses of scatterer or no scatterer at the candidate location, to compare the test statistic with a selected threshold and assign a null hypothesis value to the selected location if the test statistic is below the threshold and to assign the test statistic value to the candidate location if the statistic is above the threshold, and to repeat the process for a plurality of different candidate locations in the object to be examined to generate multi-dimensional output data.