Alignment of Schwarzchild-Chang Off-axis Telescope with a Shack-Hartmann Wavefront Sensor and Sensitivity Table Method

  • Lee, Sunwoo (School of Space Research and Institute of Natural Science, Kyung Hee University) ;
  • Park, Woojin (School of Space Research and Institute of Natural Science, Kyung Hee University) ;
  • Kim, Yunjong (Optical Astronomical Technology Group, Korea Astronomy and Space Science Institute) ;
  • Kim, Sanghyuk (Optical Astronomical Technology Group, Korea Astronomy and Space Science Institute) ;
  • Chang, Seunghyuk (Center for Integrated Smart Sensors, Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Jeong, Byeongjoon (Korea Science Basic Institute) ;
  • Kim, Geon Hee (Korea Science Basic Institute) ;
  • Pak, Soojong (School of Space Research and Institute of Natural Science, Kyung Hee University)
  • Published : 2019.10.14

Abstract

The Schwarzchild-Chang telescope is a confocal off-axis two mirror telescope with D = 50 mm, F = 100 mm and FOV = 8 ° × 8 °. Unlike common off-axis telescopes, the mirrors of the Schwarzchild-Chang telescope share their focal points to remove the linear astigmatism. In this poster, we show the alignment process of the Schwarzchild-Chang telescope with wavefront measurement and the sensitivity table method. Wavefront is measured using the Shack-Hartmann sensor, and Zernike polynomials are obtained from measured wavefront. Sensitivity table method is to calculate alignment errors from the Zernike coefficients. As a result, we evaluate tilt, decenter, and despace of each mirror of linear astigmatism-free con-focal off-axis system.

Keywords