Research On Time Reversal Mirror Passive Localization And Noise Suppression Technology Based On Vertical Array

Compared to active sonar location technique, passive location has advantages of well concealed and difficult to expose. However, the multi-path effect of the ocean environment results in received signal waveform aberration, frequency extension and decorrelation, which affect the performance of passive sonar location. The time reversal technique can integrate multi-path information and realize self-focusing on target. Vertical Array passive location technique based on Time reversal is mainly studied in the dissertation.Firstly, the thesis retrospects the methods of underwater acoustic passive location, and summarizes the TR techniques developed at home and abroad. Based on the principle of single element passive time reversa location, put forward vertica arrays passive time reversal mirror (APTRM) location technique, which realizes the passive focusing at the target position and gets higher processing gain than single element. Giving the resolvent for the sensitivity to environmen dismatch and large amount of computing of APTRM, which makes the APTRM have high location precision, and make the arithmetic robust and stable at the same time. Combined the APTRM technique with single vector sensor orientation can locate the target in three-dimention space.Intensive coherent interference will conduct the APTRM location technique disabled. The thesis brings out passive time revesal focusing and shieding method, which constructs a new scan weight vector from the APTRM. The new scan weight vector has the minimum approach error in weighted least squares with the primary scan weight vector of APTRM, after setting the zero point at the position of strong interference. TRSF can suppress strong interference and locate the weak target, and have no detecting blind area.The results of analyzing the trial data in pool prove the APTRM technique has good location performance; Under the condition of strong interferences, the TRSF technique can suppress strong interference and locate the weak target. The sea trial data processing conclusion validates the methods above are effective and feasible.