Angle-of-arrival localization of an emitter from air platforms

Air platforms can localize an emitter in 3-dimensions, by measuring the incident signal´s angle-of-arrival (AOA). The resulting localization equations are nonlinear, since they contain arctangent functions of azimuth and elevation and can be computationally complex to solve. By assuming small AOA measurement errors, this paper provides a linear formulation, leading to a closed-form, weighted least squares (WLS) estimator for the location of a non-cooperative emitter. Simulation examples show that the WLS and the optimal nonlinear least squares estimators have almost identical performance for accuracy levels attainable by modern AOA systems.