Performance Of Receiving Beampattern Of Underwater Self-guided Conformal Array

Conformal array has been an active research area during the past years for its advantages in several aspects over planar arrays. In this dissertation, an array receiving model suitable for conformal array is proposed and analysis is carried out focusing on main parameters of array beampatterns — array gain, sidelobe, and robustness. The performance of the receiving beampatterns of a sphere conformal array and a parabola conformal array is compared.The main works are as follows:1. The way to obtain the array manifold for conformal arrays is studied in this paper. For planar array, array manifold usually is got from measuring or calculating, a new method based on sound field forecast was proposed recently, in which array manifold is got through simulating the process of measuring real array manifold using ANSYS and SYSNOISE. These three methods were studied in this paper.2. Two optimal beamforming approaches for sensor arrays of arbitrary geometry and element directivity are studied. The robustness of the optimized beampatterns is studied. Based on the sensitivity analysis of the beampattern, the close form formula for sidelobe distortion of beampattern is deduced as a function of array perturbations and weighting vector norm. Using this sidelobe distortion formula, we proposed a criterion to select the upper limit of weighting vector norm with required robustness. The effectiveness of the proposed criterion and correctness of this analysis is verified via computer simulation.3. The performance of receiving beampattern of square conformal array is studied based on measuring array manifold and then compared with that of parabola conformal array by computer simulations.