DOA Estimation Of Multi-Signal Parameters With Two-Dimensional Pressure-Gradient Vector Transducer

Compared with the pressure hydrophone, vector transducer can provide both the information about pressure (scalar quantity) and particle velocity (vector quantity) of the sound field, which offers more possibilities for signal processing. So vector transducer and its signal processing have attracted the attention of researchers both native and foreign. In this thesis, a method of correlation equations for pressure gradient transducer is presented, and the estimation of multi-signal parameters with single vector transducer is given. The main contents are:1. Introduce researches about signal processing of the vector transducer both native and foreign.2. Study the working principle of the vector transducer, mainly for two-dimensional pressure-gradient transducer. And the experimental results for directional pattern of two-dimensional pressure-gradient vector transducer at frequency 3kHz and 5kHz are given.3. Deduce the relationship between sound pressure and particle velocity in plane wave. Get the approximate and the accurate correlation equations of pressure and velocity for narrowband signal, and the approximate correlation equation for broadband signal.4. Introduce the method of the Genetic Algorithms, and perform an improvement. Compared with the Simple Genetic Algorithms, the new improved Genetic Algorithms works more efficiently.5. Give some simulations about the DOA (Direction-Of-Arrival) estimation based on system of correlation equations. While the improved Genetic Algorithms was used. Comparison of the accuracy of estimation for different objective function and different values of SNR are given with narrowband signal. And validate of this method for broadband signal is also checked.