Weighted stansfield algorithm in three dimensions

In bearings-only geolocation, strategies that accurately combine both azimuth and elevation information for three-dimensional position estimation are required. This paper introduces a novel bearings-only geolocation algorithm, the Weighted Stansfield Algorithm in Three Dimensions (WS3D). This procedure uses a linearized approximation to the maximum likelihood cost for both the azimuth and elevation measurements, and uses both the bearing accuracies and estimates of the range to emitter in the zero-elevation geometric plane to minimize this cost in pair of least-squares procedures. Simulations of the new algorithm show that range and bearing accuracy weighting is important to obtain best performance. The algorithm also asymptotically outperforms a recently-derived instrumental variable (IV) algorithm for 3D geolocation designed to remove bias effects.