Abstract: Wang H presented Coherent Signal-Subspace Method (CSM),which assumed that the signal-to-noise ratio (SNR) in all narrow-band components are equal.When this is not the easel its performance will degrade consequentlyIt is a natural approaCh to average the focused narrow-band covariance matrices proportional to the SNR at each frequency.In this paper,a robust weighted focusing matrices is proposed for CSM.An explicit expression is deduced toeStimate the SNR based on studying the characteristic of covariance matrices and a more reasonable focusing matrix isformed which can improve the performance of original CSM method in aPPlication.Computer simulation,water tankexperiment and ship noise data analysis results are shown to verify the efficiency of the method.