1. A proximity sensing system comprising: transmitting means for transmitting electromagnetic radiation; a plurality of detector elements having respective adjacent fields of view and respective active where said fields of view intersect said electromagnetic radiation, said detector elements providing respective detector outputs in response to returns within said respective active regions; and processing means responsive to said detector outputs for providing a solid object target detection signal when the sum of a first group of said detector outputs exceeds the sum of a second group of said detector outputs by a predetermined amount.