中文摘要：

针对米波雷达波束宽及角分辨率低等问题，该文结合干涉雷达结构与2维方向估计方法，提出一种扩展孔径的分布式相参阵列及其2维方向估计方法。对于分布式孔径带来的测角模糊问题，该方法采用双尺度酉ESPRIT算法解模糊，再利用信号子空间与噪声子空间的渐近正交特性实现方位角与仰角的配对，从而得到高精度的方向估计，有效地扩展了孔径。最后用分段误差法（MIE）分析了分布式阵列2维方向估计的门限效应，并给出了填充系数门限与SNR门限的近似计算方法。仿真结果验证了该文提出的阵列及2维方向估计算法的有效性。

英文摘要：

Due to wide beam and low angular accuracy for VHF radar, distributed coherent arrays are proposed for aperture extension and high angular accuracy, which is based on interferometric radar principles and 2-dimensional Direction Of Arrival （DOA） estimation algorithms. Coherently combining distributed subarrays results in grating lobes and angular ambiguities for the baselines greater than subarray apertures between the phase centers of the subarrays. Two-dimensional DOA estimations with high accuracy are accomplished by dual-size unitary ESPRIT algorithm for angular ambiguities resolution and the proposed azimuth-elevation pairing algorithm based on asymptotieal orthogonality between signal space and noise space. Then distributed coherent arrays achieve effectively a large equivalent aperture. The threshold effect is analyzed with Method of Interval Error （MIE） and simple approximation eomputering methods for fillfactor threshold and SNR threshold are derived. Simulation results are presented verifying the effectiveness of the two-dimensional DOA estimation algorithm and high angular accuracy of the distributed coherent arrays.