| Popis: |
Circular Subaperture Stitching Interferometry(CSSI) and Annular Subaperture Stitching Interferometry(ASSI) were expounded to realize the test of large aspheric surfaces without the null optics.The theories and principle of the technique were analysised,and the synthetical optimization stitching model and an effective stitching algorithm were established based on homogeneous coordinate transformation and simultaneous least-squares fitting.The softwares of CSSI and ASSI were devised,respectively,then the experiment was carried out for a Φ350 mm hyperboloid by CSSI,ASSI and a null test,respectively.Experiments show that the differences of PV and RMS errors between null test and CSSI are 0.031λ and 0.004λ,and those between null test and ASSI are 0.028λ and 0.006λ,respectively,while their synthesized surface maps are consistent to the entire surface map from the null test.The technique proposed in this paper provides another quantitive measurement for testing large aperture aspheres besides the null-compensation method. |
