The radar tracking system prefers to have an estimated covariance matrix in a single snapshot in order to estimate the next position of a moving target. Recent research provides the inflation method and the projection approximation subspace tracking (PAST) method to estimate the DOA based on successive snap shots where an objective function, such as minimize the DOA estimation error, is defined and minimized. In this paper we provide complete analysis in addition to
computer simulations for the mentioned recently published DOA estimation methods. Their behaviors are compared with the traditional, parametric, Eigen decomposition and spatial smoothing methods. Although the spatial smoothing method outperforms the other traditional method, that it could estimate the DOA of both coherent and non coherent signals at higher SNR. The recent DOA estimation method provided the capability of tracking a moving source as well as estimating the DOA of fixed location source. PAST method, can track moving signal sources, which change their direction.