Acta Optica Sinica, Volume. 34, Issue 11, 1112008(2014)
Influence of Distance between the External Occulter and Object on Coronagraph Vignetting
The vignetting caused by the external occulter and support pylon of externally occulted white light coronagraph is analyzed and calculated. The coronagraph is with a field of view of 2.5~15 R⊙ (Sun Radius), a resolution of 14 sec/pixel, an aperture of 30 mm and an effective focal length of 200 mm. An analytical expression of the vignetting as a function of the distance between external occulter and objective is obtained. The vignetting figures at different distances are acquired by simulation. It is shown that the longer the distance is, the smaller the vignetting. The theoretical results are verified by actual experiments with proposed prototype of the coronagraph. The coronagraph image of target is corrected by vignetting compensation, and the image quality is improved greatly.
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Quan Wei, Zhang Zhengzheng, Zhang Hongxin, Sun Mingzhe, Bu Heyang, Wang Mingye. Influence of Distance between the External Occulter and Object on Coronagraph Vignetting[J]. Acta Optica Sinica, 2014, 34(11): 1112008
Category: Instrumentation, Measurement and Metrology
Received: Apr. 14, 2014
Accepted: --
Published Online: Oct. 13, 2014
The Author Email: Zhengzheng Zhang (buguniao3@163.com)