Research On Key Technique Of Miniaturization Multi-beam Swath Bathymeter

Multi-beam swath bathymeter is an equipment for seabed terrain survey with high efficiency, high precision, and high resolution, especially fits for wide sweep mapping. With the developing of science & technology and the changing of market demand, miniaturization of bathymeter has already become the trend of this field at present. On the basis of first multi-beam swath bathymeter of our country and referenced foreign same products, this paper proposes the design project for miniaturization. With a view to the impossibility of high frequency sea trial in developing phase for system, in this thesis the physical model has been built by means of the research of seabed reverberation producing process.With the miniaturization of multi-beam bathymetric system, array size is limited. The conventional beamformer is used by the first multi-beam swath bathymeter of our country. This method is simple, convenient and robust, but its spatial resolution depends upon the physical size of the array. How to improve the resolution of the conventional beamformer is the focus of people. This paper gives a method of virtual element beamforming technique based on linear prediction. This method does enhance spatial resolution of small array size by simulation and processing of experimental data on sea.High-resolution beamforming can get higher resolution without big array size. Therefore, it is interesting to examine how modern high-resolution beamformers work for multi-beam bathymetric system. This paper applies high-resolution beamformers to bathymetric system. The methods tested are Minimum-Variance, Eigen-Vector, MUSIC, Minimum-Norm and ESPRIT. The high-resolution beamformers reduce the beamwidth and improve the resolution by processing of experimental data on sea.