Testing of an off-axis parabolic mirror based on hybrid compensation technology

To accomplish the interference testing to an off-axis parabolic mirror, we provided a kind of hybrid compensation modal combining compensator with stitching testing. To verify the validity of the above modal, we measured a Φ1450mm off-axis parabolic mirror with the above method. It can be seen from the stitching map that the stitching map is smooth and continuous in the full aperture. At the same time, to evaluate the stitching testing accuracy, we compared the stitching testing map and the subaperture testing map. It shows that the RMS of the residual map between them is 0.003λ, verifying the validity and accuracy of the model.