Research On High Accuracy Automatic Guidance And Auto Focus Method Of Solar Telescope

The thesis firstly introduces the point-line-plane model development of the auto-guiding system in solar telescopes. The technology of large area CCD array has already substituted the point or line array model in the auto-guiding system. According to all the background information, the high-accuracy auto-guiding system of solar telescope has been studied. As the research of solar physics getting deeper, more severe requirements of telescopes have been put forward, such as more intellectualized and more automatic. And auto-focusing technology plays an important role in the auto-guiding system.A high-precision real-time guide method of solar telescopes is highly introduced in this paper. We locate the center of the full-disk solar images which recorded by large array CCD image sensor in real time and eliminate noise caused by bad weather, such as clouds and fog, as well as improving computational accuracy of centroid, by setting gray threshold, determining the location of centroid, and using the ratio of the length major axis to the length of minor axis to quantify the deviation from a perfect disk. The deviation is analyzed and changed into control signal, which, through connection-oriented TCP/IP network, drives the motor to adjust the axis of telescope. The system is close-loop control. The above-mentioned method, combining hardware architecture with software algorithms, improves the precision of guiding along with stability. Moreover, the connection-oriented TCP/IP network improves the efficiency, reliability and compatibility of the system. An Ethernet interface is also provided for remote control.In order to get the high quality images of the sun, high accuracy auto-guiding system is a must. And the adjustment of CCD’s focus is also significant to the quality of images. So the auto-focusing system is studied in chapter 5. Meanwhile, it discusses the differences of some important image evaluate functions and analyzes the methods of choosing the good function. The auto-focusing system, which combines the "distance measurement" and the discrimination of the image resolution, is studied and tested.Finally, the high accuracy auto-guiding system is applied in the HSOS’s full-disk optical telescope and the coronagraph. Some parts of the system are improved after analyzing the test data and results of the two applications. Also, a new solution is been presented. Besides, the thesis discusses the achievements, problems and suggestions of auto-focusing system in solar telescopes.