Emitter localization based on angle of arrival measurements using digital terrain elevation data

Abstract

In this paper, passive localization of an emitter by using its estimated azimuth and elevation angles, with a single moving platform is analyzed. Beyond angle of arrival measurements, the distance between target and platform is estimated by using stored digital terrain elevation data (DTED) and a better performance is achieved compared to the direction-finding (DF) only method. Location estimates found by different DF lines are combined by minimizing a defined cost function. Since this problem has not a closed-form solution, two different search algorithms are used: grid search and particle swarm optimization (PSO). Speed and performance of these two algorithms are compared. After initial position of the target is estimated, with a new measurement (azimuth and elevation angle), and the estimated distance information by using these measurements, target position is updated with Kalman filter.