Atmospheric dispersion has a great impact on high-precision astronomical observation. This paper studies the influence of atmospheric dispersion on the imaging system of large aperture astronomical telescope, and the UMAC-based atmospheric dispersion correctors (ADC) control system is designed. According to the data of zenith distance, temperature, humidity and air pressure, the influence of atmospheric dispersion on the imaging system of the telescope is calculated through the theoretical model of atmospheric refraction. The results show that when the zenith distance is greater than 24.83°, the influence of atmospheric dispersion has exceeded 0.3”, that is the requirement of telescope imaging system. So it is necessary to correct the influence of atmospheric dispersion. ADC adopts the structure of two relative rotation glued prisms. The larger the zenith distance is, the higher the requirement of the relative angle control accuracy of the two glued prisms is. According to the results of optical calculations, when the relative rotation accuracy of the two glued prisms is less than 60”, it can meet the imaging quality requirements of the telescope. According to that, the control system of ADC is designed. The rotation control of atmospheric dispersion correction mechanism adopts two-stage reduction mechanism, the first stage is reduction box, the second stage is reduction gear, and the total reduction ratio is 600:1. In order to realize the synchronous control of the two glued prisms, UMAC is used as the main controller, two servo motors are used to drive the rotation of the two glued prisms, and Renishaw encoder is used as the position feedback for position closed-loop control. The peak-to-peak control accuracy of the relative rotation angle of the control system is less than 20”, which meets the control accuracy requirements of the ADC.
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.
SONG is an international initiative to design, build, and utilize a global network of eight 1-meter class
telescopes to be operated as a whole-Earth telescope. The telescope is composed of system of azimuth axis, rotating
table, fork, system of elevation axis, top-ring, up and down truss, system of primary mirror and so on. For an
astronomical telescope mount, having a high stiffness to support the mirror cell and instruments is its basic function.
Finite element method (FEM) is a powerful tool to help structure design engineer to achieve this goal. In this paper, with
the help of ANSYS, the static and modal analysis, calculation and optimization of the SONG telescope mount will be
given. The modal result which is used for avoiding resonance and fatigue failure of the telescope acquire natural
frequency of telescope. The FEM results show that the structure, designed for SONG telescope, is feasible and reliable
and have a high stiffness-to-weight ratio to meet the optical demands.
It's a very important point that fully open up power of Gou Shoujing telescope (LAMOST) in exoplanet detection field
by developing a multi-exoplanet survey system. But it's an indisputable truth in the present astronomy that a traditional
type of multi-object high resolution spectrograph is almost impossible to be developed. External Dispersed
Interferometry is an effective way to improve the radial velocity measuring accuracy of medium resolution spectrograph.
With the using of this technique, Multi-object Exoplanet Search Spectral Interferometer (MESSI) is an exploratory
system with medium measuring accuracy based on LAMOST low resolution spectrograph works in medium-resolution
mode (R=5,000 - 10,000). And it's believed that will bring some feasible way in the future development of multi-object
medium/high resolution spectrograph. After prototype experiment in 2010, a complete configuration is under the
development, including a multi-object fixed-delay Michelson interferometer, an iodine cell with multi-fiber optical
coupling system and a multi-terminal switching system in an efficient fiber physical coupling way. By some effective
improvement, the interferometer has smaller cross section and more stable interference component. Moreover, based on
physical and optical fiber coupling technique, it's possible for the iodine cell and the switching system to simultaneously
and identically coupling 25 pairs of fibers. In paper, all of the progress is given in detail.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.