A Study About Normal Mode Decomposition By Vector Sensor Array

The normal mode theory is an effective method to model the sound field in the shallow water, especially for the low frequency sound propagation. The normal mode decomposition can be taken as technique support for environmental parameter estimation, passive source localization and single mode technique. Many kinds of normal mode decomposition method have already been derived using pressure hydrophone array. But the performances of these methods are too sensitive to the signal to noise ratio. Using the vector hydrophone array the energy flux in the underwater acoustic channel can be measured. In this thesis, a normal mode decomposition method using vector hydrophones is derived since that the signal processing methods based on the acoustic energy flux measurement can improve the SNR which has already proved by many theoretical and experimental researches. The performance of this method under different kinds of noise backgrounds is analyzed and it is compared with the performances of the methods using pressure hydrophone array. It has been proven by the simulation that the performance of the method using vector hydrophone array is better than those using pressure hydrophones in low signal to noise ratio background.