Research On High Resolution Stratified Atmospheric Turbulence Measuring Instrument And Its Application

Atmospheric turbulence is the primary source that affects the quality of ground-base telescope image.To choose the sites(astronomical site selection)of atmospheric stability through the qualitative measurement of atmospheric turbulence and give full play to the role of telescope are very important basic work for the construction and operation of ground-based telescopes with any size.The integral results of the whole layer of atmospheric turbulence were mainly measured in previous astronomical site selection.With the development of adaptive optics,the high-precision of stratified atmospheric turbulence information has become more and more important because the stratified atmospheric turbulence information can provide indispensable parameters for the design of adaptive optics system,especially the design of wide field adaptive optics system.The measurement technology of stratified atmospheric turbulence has been a research focus in recent years.Currently,atmospheric stratification turbulence is measured mainly based on the observation of binary star at night.However,few equipment can be used for the stratified atmospheric turbulence measurement during the day.Besides,the existing stratified atmospheric turbulence measuring equipment is big,and is not suitable for astronomical site selection.Based on the theory of atmospheric turbulence,this thesis analyzes the existing technical characteristics of the stratified atmospheric turbulence measuring equipment,and develops a set of stratified atmospheric turbulence measurement equipment suitable for daytime and nighttime.Through analyzing and improving the error of the measuring equipment,the thesis effectively improves the performance and the measuring precision of the equipment,and conducts automatic improvement of the whole equipment,and make it effectively apply in astronomical site selection point monitoring of Nameless Mountain(4800m in height)in Daocheng County.This thesis first introduces the characteristics of atmospheric turbulence and its influence on telescope image as well as the overview of adaptive optics technology,and then reviews the important technical progress in the field of atmospheric turbulence measurement in China and foreign countries in recent years,and briefly analyzes the development prospects of stratified atmospheric turbulence measurement technology in China.Secondly,from the aspect of the analysis and design method of the existing stratified atmospheric turbulence measurement equipment,their respective advantages and limitations are analyzed.And then,the method based on binary star observation at night is analyzed and improved;and the method that can realize stratified atmospheric turbulence measurement for day and night is proposed based on the surface source(the sun and the moon)edge wave front arrival Angle jitter.Besides,and the method the theoretical analysis and simulation analysis are conducted on the method.The simulation results show the feasibility of this method.the first stratified atmospheric turbulence measurement test is successfully realized on a 20 cm aperture telescope based on the proposed method.Thirdly,in order to get high-precision of stratified atmospheric turbulence measurements,a set of 50 cm aperture telescope system is designed.Its back-end optical path is designed and improved to make it achieve high resolution of difference imaging for surface source.The autocorrelation jitter and covariance of difference image edge points wave front arrival angle are measured.Moreover,high-precision of measurement is conducted on the stratified atmospheric turbulence according to the optical characteristics of atmospheric turbulent model.And the equipment is applied to the actual site monitoring of the Nameless Mountain in Daocheng County,and the actual stratified atmospheric turbulence information is obtained for the first time.Finally,the equipment is automatically improved;the error source is analyzed and processed.Cross-comparison is conducted on it and other types of stratified atmospheric turbulence equipment.The automation improvement mainly includes the automatic control of the telescope,servo control of the dome,and the remote control.Error source analysis and processing mainly involve the error of telescope optical system,the error caused by exposure time and processing,and the location error of the difference surface source image edge point.In the cross-comparison,other types of stratified atmospheric turbulence equipment mainly involve LUCIES,SHABAR,etc.The reliability and measurement accuracy of the equipment are improved through these improvements.The research and test results show that the equipment can realize high precision of(50m each layer)measurement of atmospheric turbulence profile from near the ground to 20 km of altitude,so it can be effectively applied in the stratified atmospheric turbulence measurement of astronomical site selection.In this thesis,based on the urgent need of stratified atmospheric turbulence measurement in the current astronomical site selection,the stratified atmospheric turbulence measurement method and technology based on the edge of surface light source is conducted.A high-precision of stratified atmospheric turbulence measurement equipment is successfully developed.A series of practical measurement research is implemented,which greatly promotes the astronomical site selection of the Nameless Mountain.Besides,the research also has much research significance and reference value for the astronomical site selection in China.