An image of a target (11) is produced by illumination of the target (11) with overlapping fields (18, 20) of wave energy, such as coherent light, producing an interference pattern (22) moving across the target. At least one pair (12) of sources (14, 16) wave energy provide the moving interference pattern (22). The scattered illumination reflected from the target is detected by a non-imaging receiver (24); a two dimensional spatial frequency map is recorded (30, 62), based upon the amplitude, fre...