拼接干涉仪存在机械定位误差，各子孔径间存在相对定位误差，给拼接结果带来影响，需要通过子孔径拼接算法进行补偿。为了提高子孔径拼接算法的补偿能力，提出了有别于基于原始图像计算补偿量的子孔径拼接新算法。将待拼接的图像变换成利于计算补偿量的图像，用变换后的图像进行计算并得到子孔径的相对位置关系，利用得到的相对位置关系将原图像拼好。针对拼接干涉仪机械定位精度较高的情况，设计了一种将原图变换成其梯度的幅值图和方向图，用幅值图作为权重，通过将方向图吻合计算补偿量的新算法。仿真结果表明，该算法相比于用原图计算补偿量的算法，更好地补偿了机械定位误差的影响。以全口径直接测量结果为标准，实验结果进一步验证了这个算法的有效性。说明了根据实际情况选取恰当的变换，基于变换的子孔径拼接算法能提高拼接精度。

Sub-aperture stitching algorithm should compensate the mechanical location errors in sub-aperture stitching interferometer because they lead to the relative location errors between sub-apertures which affect the stitching result. In order to improve the compensation ability of sub-aperture stitching algorithm, a new stitching algorithm different from the calculation compensator algorithm using original pictures is proposed. The new algorithm transforms original pictures into images beneficial to the calculation of compensator and calculates the location of each sub-aperture using pictures after transformation. It stitches original pictures using the calculated locations. Due to the high location accuracy of the sub-aperture stitching interferometer, the new algorithm transforms original pictures to gradient norm pictures and gradient direction pictures, and calculates the compensator based on direction pictures using norm pictures as weight. The simulation result shows that this algorithm compensates location errors more effectively than the calculation compensator algorithm does. In comparison with full-aperture testing, sub-aperture stitching result demonstrates the validity of this algorithm, and indicates that the method can enhance the location errors compensation ability by choosing a proper transformation.