Reconstruction of direction of los arrival for passive emitter localization

The performance of conventional location methods degrades dramatically due to non-line-of-sight (NLOS) propagation. In NLOS situation, the direction of line-of-sight (LOS) arrival is not easy to reconstruct without any effective constraints. In this paper, an elliptical constraint based method is proposed to estimate direction of LOS arrival. A set of linear equations is developed based on the joint estimation of direction of arrival (DOA) and Doppler frequency of arriving rays. Numerical simulations show the direction of LOS arrival can be estimated with higher probability and accuracy in serious NLOS environment.