An Angle Weighted Least Squares Algorithm for Target Localization

In the three-dimensional localization algorithm based on direction-of-arrival(DOA), the target’s location errors are sensitive to the estimation errors of pitching angles, especially when the sensor array nodes are almost in the same horizontal plane with the target. In other words, the location errors are highly sensitive to the pitching angle errors when the pitching angles are close to 90°. To solve the sensitivity problem, a weighted least squares method is proposed in this paper. Small weighting factor is chosen for those sensor array nodes with large pitching angle estimation to decrease the impact of pitching angle estimation error and to increase robustness of the method. Furthermore, the performance of the weighted least squares method is analyzed via numerical simulation. Simulation results show that the present weighted least squares method has better robustness over DOA estimation errors and disturbance of the sensor array nodes than ordinary least squares method.