The conceptual design and simulation of 30m RIT

As one of the preliminary research projects of Chinese ELT, 30m RIT--Ring Interferometric Telescope are being simulated and tentatively designed by Yunnan Astronomical Observatory, CAS. The simulations of 30m RIT are mainly included as follows: PSF transform and the image quality at limited photons mode, active control mode of the primary ring mirror, the phasing mode of 30m segmented ring mirror, the turbulent atmosphere and adaptive optics etc. This paper also introduces some tentative design results of 30m RIT, such as the optical design, the conceptual design of the enclosure. The astronomical experiments at seeing limited case and diffraction limited case are introduced in this paper too. A ring aperture mask was put on the entrance pupil of a one meter telescope, real astronomical objects were observed by this "ring telescope" and reconstructed by high resolution imaging techniques such as speckle masking, iterative shift and add methods. The diffraction imaging ability and the full u-v coverage property of a ring aperture were proved by these astronomical experiments.