在瑞奇－康芒定量检测中，被检数据中除了被检平面本身所固有的像散以外，还存在由于大曲率所造成的像散，这样就很难得到准确的被测平面面形误差，给指导镜面加工带来困难。对瑞奇－康芒检测法中由于瑞奇角产生的压缩图像进行展开，同时旋转被测平面进行推导，该方法将被检平面高低误差和被检平面本身的像散进行分离，使得检测结果更加准确地反映被检平面面形。通过与其它检测方法的比对，可以证明此方法的可行性、可靠性。给出了大天区面积多目标光纤光谱望远镜(LAMOST)项目中的MA大口径平面子镜的检测实例。

Besides the intrinsic astigmatism of the mirror plane under test,astigmatism due to large curvature is encountered in quantitative. Ritchey-Common test,bringing in difficulties to the accurate determination of surface shape error,and in turn to the accurate machining of mirror plane. A method which expands the compressed images due to Ritchey Angle and rotates the plane under test is presented. By derivation based on the obtained relationships between the original plane and the rotated plane,the effect of intrinsic astigmatism and the undulate error of the plane under test can be separated,leading to a better agreement between the test result and the actual surface shape under test . Comparison with results by other test methods proved the feasibility and reliability of this method. The method's application in test of large aperture MA plane submirrors in LAMOST project is presented.