深海声信道中的被动合成孔径

发布时间：2018-03-07 23:20

本文选题：被动合成孔径　切入点：物理子阵　出处：《中国科学:物理学力学天文学》2016年09期 　论文类型：期刊论文

【摘要】：被动合成孔径技术通过对直线运动的小孔径基阵的接收信号进行处理,以时间积累换取空间增益,从而提高对目标的方位分辨和检测能力.理论分析表明,只有当(用于合成孔径的)物理子阵所处声场的水平相关半径远大于合成所用子阵尺寸时,被动合成孔径的探测性能才会较常规物理孔径基阵有明显优势.深海声信道中,声场水平相关的空间变化会对被动合成孔径技术的性能存在较大影响,本文利用2014年南中国海深海信道条件下的实验数据,开展了被动合成孔径和常规物理基阵的性能对比分析,用波束域扩展拖曳线列阵测量方法将32阵元(48 m)的物理子阵合成了160阵元(240 m)的虚拟阵,结果表明:当声场水平相关半径超过240 m时,160阵元虚拟阵的处理增益最高比32阵元的物理子阵高出9.5 dB,与理论预测数值一致;当水平相关半径小于30 m时,160阵元虚拟阵的处理增益只比32阵元的物理子阵高出6 dB,而其探测性能实际已经接近32阵元物理子阵.这也说明,在深海信道影区内声场水平相关半径较小,被动合成孔径技术的探测性能因此受到限制,较之常规物理孔径基阵的优势并不明显;而在声场水平相关半径较大的深海信道会聚区内,被动合成孔径技术的探测性能有明显改善,较之常规物理孔径基阵的优势明显.
[Abstract]:By processing the received signals of linear small aperture array, passive synthetic aperture technology gains spatial gain in exchange for time accumulation, thus improving the azimuth resolution and detection ability of the target. Theoretical analysis shows that, It is only when the horizontal correlation radius of the sound field of the physical subarray (used for synthetic aperture) is much larger than the size of the sub-array used in the synthesis that the detection performance of the passive synthetic aperture is significantly superior to that of the conventional physical aperture array. The performance of passive synthetic aperture technology will be greatly affected by spatial variation of sound field level. In this paper, we use the experimental data of the deep sea channel in the South China Sea on 2014. The performances of passive synthetic aperture and conventional physical array are compared and analyzed. The physical subarray of 32 array elements (48 m) is synthesized by using beamspace extended towed linear array measurement method, and the virtual array of 160 array elements (240 m) is synthesized. The results show that when the horizontal correlation radius of sound field exceeds 240 m, the maximum processing gain of the virtual array is 9.5 dB higher than that of the physical subarray of 32 elements, which is in agreement with the theoretical prediction. When the horizontal correlation radius is less than 30 m, the processing gain of the virtual array is only 6 dB higher than that of the physical subarray of 32 elements, and the detection performance of the virtual array is close to that of the physical subarray of 32 elements. In the deep sea channel, the horizontal correlation radius of sound field is small, so the detection performance of passive synthetic aperture technique is limited, and the advantage of passive synthetic aperture array is not obvious compared with conventional physical aperture array. In the deep sea channel convergence region with large horizontal correlation radius of sound field, the detection performance of passive synthetic aperture technique is obviously improved, and the advantage of passive synthetic aperture array is obvious compared with conventional physical aperture array.
【作者单位】：中国科学院声学研究所声场声信息国家重点实验室;中国科学院大学;
【基金】：国家自然科学基金资助项目(编号:11434012,4151101011,11174312,11404366)
【分类号】：P733.2

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