前视声呐圆弧接收阵列结构优化设计

针对前视声呐线阵波束形成各向同性较差及半圆阵有效孔径受限的问题,提出了一种优化的圆弧接收阵列结构设计方法。根据不同的成像开角,设计圆弧接收阵圆心角使全部阵元参与所有来波方向的波束形成。建立圆弧接收阵的远近场聚焦模型,并推导圆弧接收阵的指向性函数,根据边界波束栅瓣阈值条件计算具有最佳波束性能的圆弧接收阵半径。对圆弧阵、线阵及半圆阵在不同扇区开角下的波束性能及扫查开角120°、纵深100 m的仿真图像对比表明,在成像开角为90°到130°时,圆弧接收阵主瓣性能提升了8%,边界波束栅瓣级优化了4%,交叉向分辨深度相对线阵与半圆阵分别增加了20 m和45 m,同时参数存储量仅为线阵的2.7%。该阵列兼具有效孔径大、波束各向同性的优点,能有效提高前视声呐系统探测性能,并降低算法实现难度。 

Structural optimization design on the arc receiver array of forward-looking sonar

Aiming at the problems that linear array is poor isotropic and limited effective aperture of semicircular array in forward-looking sonar,an optimized structural design method of arc receiving array is proposed.According to different extent of imaging sector,the central angle of arc receiving array is designed to make all elements participate in beamforming of all directions.The far and near-field focusing model of arc receiving array is established,and the directivity function of arc receiving array is derived.Calculate the radius of arc receiving array with the best beam performance according to the threshold condition of the boundary beam grating lobe.The comparison of the beam performance at different sector extent of arc array,linear array and semicircular array show that when the view extent is between 900 to 1300,the main lobe performance of the arc receiving array is improved by 8%,the grating lobe level of the boundary beam is optimized by 4%.The comparison of simulation images with the view extent of 120°and depth of 100 m show that the cross-directional resolution depth is increased by 20 m and 45 m compared with linear array and semicircular array,the parameter storage capacity is only 2.7%of the linear array.The arc array has the advantages of large effective aperture and isotropic beam,which can effectively improve the detection performance of forward-looking sonar system and reduce difficulty of algorithm implementation.