基于虚拟孔径扩展的稀疏嵌套阵设计

为提高阵列自由度，提出了一种稀疏嵌套阵设计方法.该方法将增广嵌套阵（augmented nested array，ANA）中右侧子阵阵元与中间子阵距离稀疏化，从而扩展最远孔径.为保证虚拟孔径连续性，进一步提出了一种新型嵌套阵，即单侧稀疏嵌套阵.与ANAI-2、改进嵌套阵和最大阵元间距约束（maximum inter-element spacing constraint，MISC）阵列相比，该结构具有更长的连续段.仿真实验验证了提出结构在自由度、估计精度方面的优越性. 

Sparse Nested Array Design for Virtual Aperture Extension

A sparse nested array concept of distributing the right-side elements of two level augmented nested array (ANA) sparsely was proposed for degree of freedom (DOF) enhancement. The new strategy was arranged to make the distances between the right-side elements and the right most sensor in the middle subarray of ANA larger than N₁ to extend the furthest aperture successfully. In order to keep the continuity of virtual aperture, a new nested array, referred to as one side sparse nested array (OS-SNA), was proposed. Compared with the improved nested array ANAI-2 and maximum inter-element spacing constraint (MISC), the new nested array can generate more consecutive lags. Simulation results show the superiorities of the proposed OS-SNA in DOF and the precision estimation.