中文摘要：

方位多通道SAR用于高分辨率宽测绘带成像有着广阔的前景，然而通道失配引起的通道相位误差会较大地影响成像的质量。针对这一问题提出了一种改进正交子空间（OS）算法用于校正通道相位误差。改进OS算法的通道相位误差估计考虑了天线方向图加权，并利用全部多普勒频点信号子空间与噪声子空间的正交约束条件建立代价函数，从而得到相位误差估计的最优值。该方法有效克服常规正交子空间算法利用单个多普勒频点估计通道相位误差时的不稳健问题。基于机载实测数据的实验验证了改进0s算法的有效性和稳健性。

英文摘要：

Azimuth multichannel synthetic aperture radar system is very promising for high-resolution and wide-swath imaging, whereas the channel phase error due to channel mismatch has a great influence on image quality. This paper brings up an improved orthogonal subspace（OS） method to calibrate the channel phase error. The improved OS method takes antenna patterns as the weight, and applies the orthogonal restriction of signal subspace and noise subspace for all Doppler bins to establish the cost function, so the optimal chan- nel phase error estimation can be obtained. This method avoids the unstable problem of channel phase error estimation of the conventional OS method which uses single Doppler bin. The experiments using some real airborne multichannel SAR data demonstrate the effectiveness and robustness of the improved method.