Design concept of geostationary Earth observation segmented telescope and the wavefront management scheme

Abstract

For crisis management and monitoring, a geostationary Earth observation telescope with large segmented aperture is investigated in JAXA. The preliminary study showed the feasibility of the aperture size of 3.6 m consisted with six primary mirror segments and the fundamental optical design. In order to obtain nearly diffraction limited performance with the optical system in the orbit, the aperture synthesis and wavefront error correction have to be conducted through precise alignment procedure, and therefore the system needs to equip several actuators and sensors dedicatedly designed for the purpose. We constructed the system design through the combination of structural-thermal analysis and optical consideration, and then planned the alignment procedure after launch. Those design concept are planned to be tested in the miniature testbed of segmented optical system under construction. We show the testing equipment and procedure for segment co-phasing and wavefront correction intending in space use.