Simulation Research Of Imaging Algorithm For 3-D Imaging Sonar

As the conventional 2-D imaging sonar can not fully meet the demands for underwater detection anymore, the sonar system that can provide real-time 3-D images underwater become more and more important. But the real-time 3-D imaging sonar usually depends on 2-D planar array or acoustic lens technology, which are much more complex and expensive than linear array. In this paper, some new 3-D imaging methods that depend on an L shaped array are proposed.A new method that makes use of conventional beam-forming technology is proposed. Its basic principle is multiplying the beam-forming data received from one of the linear array and the beam-forming data received from another linear array together to forming a group of new data, and then forming the 3-D imaging of the object region based on this new data. 2-D images can also be drawn at the same time. With the help of 2-D images, the 3-D imaging of the object region can be more complete.MSB-RMU algorithm is a high resolution DOA estimation algorithm with less SNR requirements than conventional ones. In this paper, 1-D MSB-RMU algorithm develops into 2-D MSB-RMU algorithm by using L shaped array. It can be used for 3-D imaging after parameter matching. Two parameter matching methods are applied. They both depend on the estimation of the strength of target and have some differences in the procedure of matching. Then a new method that combines 1-D MSB-RMU algorithm with 2-D MUSIC algorithm is mentioned too. There is no need to use parameter matching method in this new algorithm. And it can be used for equal-power targets estimation.At last, a simulated imaging model is built and the methods mentioned before are applied. The results of algorithms that use high resolution DOA estimation technology turn out to be much better than the others. The two high resolution algorithms have the same performance to the targets of different strength. But 2-D MSB-RMU algorithm will fail if the targets are have same strength. And this will not happen to the other algorithm.