Direction-finding results for a Vector Sensor Antenna on a small UAV

On small platforms, angle-of-arrival (AOA) estimation of an E-M signal can be accomplished with colocated antennas measuring multiple components of the propagating wave. An electrically small Vector Sensor (VS) Antenna constructed above and below the wing of a small UAV measures three components of the propagating wave. Determining the AOA involves fitting known "calibration" AOAs and corresponding antenna response to a modeled response. The least-squares calibration approach described here determines the azimuth and elevation AOAs for sources located at typical elevation angles to within a few degrees, agreeing with the Cramer-Rao Lower Bound (CRLB). These results justify the use of small VS antennas to do direction finding (DF) in high SNR environments.