Abstract: The present invention provides an antenna system for use in determining N unknown parameter values relating to an object located in the vicinity of the system. One embodiment of the system includes a body with a longitudinal axis and a plane that is substantially perpendicular to the roll axis. The system further includes an antenna array comprised of a plurality of elements, each of which is located in a ring in the noted plane and separated from each of the other elements by less than 180° relative to the longitudinal axis. Also included in the improved antenna system is a beamformer for producing N+1 beams and a device for using the N+1 beams to determine N values associated with the object.