Nanshan 26 m Radio Telescope (NSRT) constructed in Nanshan Urumqi, Xinjiang, China, it is a fully steerable radio telescope, the observing frequency up to 43GHz. The telescope was refurbishment in 2015 after 20 years operation. A rapid feed switching mechanism was designed and installed on antenna sub-reflector. The mechanism including a “hexapod” structure which used to adjustment the sub-reflector supporting legs deformation at difference elevation angles, and a turret used to changing the position of light source focus to meet the different feeds requirement. All the feeds distributed on the circle of Cassegrain focal plane. An overview of the mechanism design, FE (finite element) analysis and kinematics simulation will be show in this paper.
Nanshan Radio Telescope (NSRT) constructed in Nanshan Urumqi, Xinjiang, China, it is a fully steerable radio telescope. It contribution not only the Chinese astronomy community but also an important member of international VLBI net. After more than 20 years operation the telescope was refurbishment in 2015. In this paper an overview of the refurbishment project will be introduction, actually except the alidade all the antenna structures and systems were rebuilt. Now the observing frequency is up to 43GHz, the accuracy of reflector surface is 0.3mm (r.m.s) at the best adjustment angle, the pointing accuracy is 10 arcs, after 2 years operation the antenna reached a good condition, more details will be shown in this paper.
The Nanshan radio telescope (NSRT) is a fully steerable radio telescope with a diameter of 26 meters, located in Urumqi, Xinjiang, China. The NSRT currently operate in the frequency range from 1.4 GHz to 22.4 GHz。In order to reduce effect of gravity-induced structural deformations on antenna efficiency and pointing accuracy, the subreflector adjustment system has been used to adjust subreflector position in 6 degree-of-freedom to correct subreflector defocusing and reflectors misalignment. The Stewart platform is used as the adjustment mechanism to perform translation -50/+50 mm (along x, y, z axis) and rotation -5/+5 degree (with respect to x, y axis) with repeated positioning accuracies of 0.07 mm (translation) and 0.01 degree (rotation). The paper will mainly introduce an overview of the NSRT subreflector adjustment system, including Stewart platform and control system, performance testing, and position adjustment of subreflector.
The QiTai radio Telescope（QTT） has completed the conceptual design phase and several key-point researches in the next phase have already begun. Analyses show that the antenna meets the requirements for electrical performance and pointing accuracy specified in the objectives of the phase with highest degree. However, several challenges for structure design remain. In this paper, we will outline the challenges in antenna structure design including antenna weight vs. stiffness, reflector and alidade connecting, reflector surface dividing, actuator, azimuth track, etc. and discuss current progress on resolving these issues.