参考面二阶项(离焦和像散)误差是导致拼接累积误差的主要因素,而参考面高阶误差会导致高频面形误差。分析由参考面误差二阶项和高阶项导致的拼接误差的规律。研究参考面误差导致任意两个子孔径拼接误差之间的关系。提出一种可以有效减小参考面高阶项误差对子孔径拼接结果影响的算法。该算法将拼接后的子孔径面形数据对应相减,分离出参考面高阶项误差的拼接误差。数据仿真和实验验证表明了该算法的正确性和有效性。

The second-order (defocusing and astigmatism) error of the reference surface is the major factor that results in accumulated stitching errors, whereas the higher-order errors of the reference surface will result in high-frequency shape errors. Subsequently, the law of stitching errors caused by the second- and higher-order errors of the reference surface is analyzed, and the relation between any two subaperture stitching errors that can be attributed to the reference surface error is studied. Further, an algorithm is proposed to effectively reduce the influences of the higher-order errors of the reference surface on the subaperture stitching results. The stitching errors of the higher-order errors of the reference surface are isolated using this algorithm to eliminate the stitched surface data of any two subapertures. Furthermore, the validity and effectiveness of this algorithm are verified using simulations and experiments.