The sample covariance matrix (SCM) and normalized sample covariance matrix (NSCM) are the general estimators to estimate the covariance matrix of high-resolution sea clutter. Although two estimators have been proposed for a long time, their impacts on the spatially and temporally nonstationary sea clutter have not been analyzed until now. The adaptive normalized matched filter (ANMF) and block-ANMF detector are utilized to analyze the detection performance of those two estimators in spatially and temporally nonstationary sea clutter. It provides a theoretical guidance for the marine radar to detect targets. (4 pages)
