The Multi-channel Photometric Survey Telescope (Mephisto) is a wide-field ground based telescope with a 1.6m primary mirror and 2° field of view, proposed by Yunnan University. The telescope will be capable of imaging the northern sky in three colors simultaneously and deliver a colored movie of the universe. The R-C system with lens corrector was adopted as the optical system considering of the image quality requirement, light obscuration and camera arrangement, in which three cubic splitters were adopted for the three channel beams in order to get satisfied image quality over the whole field of view. Dichroic coating on the cubic will lead to nonuniform efficiency on the focal plane due to the polarization problem and wide incident angle, which need calibration. The image quality represented in 80% encircled light energy is around 0.6arcsec. In order to keep the optimal image quality in any operational conditions, a 5-DOF mechanism was designed to actively adjust M2 mirror positions according to the wavefront sensors or by direct star psf. Now the telescope are under developing in Nanjing, expected to be installed at Lijiang observatory before the end of 2021.
Stellar Observations Network Group, SONG, is a Danish led international collaboration project to construct a global network of small 1m telescope around the globe. The second 1 meter SONG node telescope designed by NIAOT is installed at Delingha site in west China.
TCS hardware is based on PC, UMAC, tape encoder, motor and driver. TCS software is developed in powerful Qt Creator environment under stable Debian 6.0 operation system. The design rules are modularity and simplification. Several software modules work together to realize telescope usual function . Tracking algorithm is comprised of two parts. One is UMAC motion program, another is tracking thread in PC program. Communication between TCS and OCS is complicated. The method to process remote command is described.
SONG (Stellar Oscillation Network Group) is an international project to form a global observing network of eight 1- meter class telescopes. China joined this project and funded one node telescope for this network. By the end of 2013, the Chinese SONG telescope has been installed on the Delinha observing site of Purple Mountain Observatory in Qinghai province. This paper will give the introduction of this telescope, including its optical system, structure and control system. Besides, the preliminary observing performance of the telescope on site will be given in the second part of this paper.
The CCD Auto-Guiding Star System is a significant part in the telescope control system for minimizing the tracking
errors, and acquiring high-resolution data. In this paper, the improved algorithms of the off-axis CCD Auto-Guiding Star
System is designed and applied. Especially the de-rotator algorithm is added for the large-field Alt-Az Telescope to keep
stars at original positions. The software that can communicate with the CCD camera is designed to collect, analyze and
process data, and then sent data to Alt-Az control system in real time less than 160ms. The algorithms to calculate
centriod of stars are novel. The experimental results were high-resolution and reliable for system, the RMS of star offset
vector can arrive 0.03 pixel. In addition, experiments showed that the software could work steadily in long time. Now the
CCD Auto-guiding software has been applied on the f/8 reflecting Alt-Az telescope with 2.5m aperture, 1-degree field of
A 5-meter terahertz telescope is proposed by the Chinese Center for Antarctic Astronomy (CCAA) for the East
Antarctica site of the Dome A plateau. The Dome A 5-m terahertz telescope (DATE 5) will be operated at sub-millimeter
waveband taking the unique advantage of the transparent atmospheric windows between 200 and 350 μm wavelengths at Dome A. A preliminary design has been conducted according to the given technical requirements and the special environmental conditions at Dome A. A symmetric R-C Cassegrain optical system is designed for the telescope, with a primary f-ratio of 0.4 and a wide field of view of 10 arcmin. The magnification of the sub-reflector is 9.4, leading to the final focal ratio of 3.76 and the focus 0.2 m below the vertex of the primary reflector. To ensure surface accuracy of the reflectors precise as small as 10 um RMS, we consider using Carbon Fiber Reinforced Plastics (CFRP) to build the backup structure (BUS) of the primary reflector and the sub-reflector itself. An alt-azimuthal mounting is adopted and a tall base structure beneath the telescope is set up to lift the telescope above the low atmosphere turbulent layer. All the mechanics, as well as control electronics, are strictly designed to fit the lower temperature operation in the Dome A environment. This paper is to generally present the mentioned systematic optical, structural and electronic design of the DATE 5 telescope.
LAMOST experiment set is a special reflecting Schmidt telescope set up at the camps of NIAOT (Nanjing Institute of Astronomical Optics & Technology). Its optical configuration and tracking formulas are given. The difference between LAMOST experiment set and general alt-azimuth telescope is analyzed. The method for getting pointing error data from ST-7 CCD image is discussed. A TPOINT like approach for the pointing model was chosen. The procedure for the development of the model is described. As result we got 4.35" rms accuracies.
The behavior of future LAMOST mount tracking is one of crucial issues for the telescope's overall performance. In order to demonstrate and to sense the real situation to some degree, the LAMOST team has set up a model mount at the camps of Nanjing Institute of Astronomical Optics & Technology. Painstaking effort has been made during the course of the interim outdoor test to improve the accuracy of the model mount tracking. The major test progress, starting from scratch to date, has been recorded in this paper, such as the anti-disturbance measures taken, the cascaded feedback application, the two-motor-differential drive till the overhaul of the model mount in its drive mechanism, etc. The tracking accuracy has been dramatically improved up to 0.35"-0.42" RMS, promising the future LAMOST tracking requirement will be met given more reliable mount and sophisticated control system.
Active optics is the most difficult part in LAMOST project. Especially for the segmented reflecting Schmidt plate Ma, in which both segmented mirror active optics and thin mirror (or deformable mirror) active optics are applied. To test and optimize the thin mirror active optics of Ma, and to approach the reality of operating environment of the telescope, an outdoor experiment system has been established. This experiment system is also a 'small LAMOST' with one sub-mirror of the primary mirror Mb and one sub-mirror of the Schmidt plate Ma, and with full scale in spacing (40 meters) between Ma and Mb. many parts of LAMOST were tested in the experiment system except segmented mirror active optics. Especially for force actuators, thin mirror support system, friction driving of the alt-azimuth mounting and its control system, wave front test along such a long optical path. This paper presents the experiment system, research and developments, and some experiment results.