PAssive Synthetic Aperture (PASA) is a technique of include localization, detection, classification and target increasing the length of a small array artificially through array towing tracking. In particular, localization may be achieved by motion and signal processing. This allows the user to obtain the beamforming, which combines the outputs of individual advantage of a long array while maintaining the maneuverability of a transducers in an array in order to estimate the direction of short array. In recent years, there have been keen interests in improving the ETAM technique to overcome its disadvantage. arrival of plane wave signals.