The present invention provides an improved antenna
system that, in one embodiment, includes an
antenna array comprised of a plurality of elements, each of which is capable of providing a
signal. Also included in the improved antenna
system is a multi-beam beamformer for producing two spatially independent overlapping beams from the signals provided by two different subsets of the
antenna array. The phase of the two beams is compared to realize an interferometer that can provide high or
fine resolution data on the position of an object relative to the antenna
system. The amplitude of the two beams can also be compared to obtain coarse data on the position of the object. The beamformer includes a switching network for selecting which elements of the
antenna array form the two subsets. This permits, for example, the position of the beams to moved, the baseline of the two beams to be varied, and / or the beam width of the beams to be altered. To reduce adverse aerodynamic effects in certain applications, the antenna array is located conformal to the exterior surface of the body on which the array is mounted. Further, to reduce temperature related problems associated with high speed movement of the body on which the array is located, the array is located on the side of the body, as opposed to the front of the body. The side location also provides space for other types of sensors that are preferably located adjacent to the front surface of the body.