中文摘要：

针对水下小孔径作战平台信号处理问题，给出了声呐阵列虚拟扩展技术的性能评估方法．建立了水下声传感器阵列虚拟扩展后的数学模型，推导了阵列实阵元总数、虚拟的新阵元数和虚拟一个阵元使用的实阵元数之间的数学关系式．给出了虚拟扩展后的阵列信噪比增益数学表达式，并分析了其与实阵元总数、虚拟的新阵元数和信号入射角度之间的关系．通过对虚拟扩展后阵列波束图的分析，论证了阵列波束宽度的变化及多目标分辨能力的改变．最终通过对扩展后阵列信噪比增益及多目标分辨能力的理论分析和计算机仿真，论证了虚拟扩展技术对阵处理增益、波束宽度等阵列主要性能指标的影响，并对该技术在实际工程应用中的适用条件讲行了分析．

英文摘要：

The proposed research derives from signal processing problem of underwater small aperture battle platform, and performance evaluation method for sonar array virtual extension. Through establishing the mathematic model of underwater acoustic sensor array after virtual extension, the mathematical relation representation of the total number of true array units, the numbers of virtual units and true units is derived. In addition, exploration, which, span a new virtual unit will also be reviewed. The mathematical representation of gain of array SNR is deduced and the relation of variables of number of total true units, number of virtual units and entrance angle of the target signal is illustrated. Analyses of the change of beam width and ability to distinguish multiple targets after virtual extension are provided in the research. Through theoretical analysis and computer simulation, the array SNR gain after extension and the multi-object resolution, the influence of virtual extension on array gain, beam width, etc. are demonstrated, along with the analysis of applicable condition in engineering practice.