Research On Measurement Method Of Turbulence Profile Based On Moon Edge Image

Measurement of the atmospheric optical turbulence parameters over real-time and long-term has become a important part of the running of ground-based Observatory. It not only as a major indicator of the performance of the Observatory site, but also has important influence on the initial design, observing performance and improvement of the precision of high-resolution astronomical imaging techniques (including adaptive optics and astronomical optical interferometry). The atmospheric optical turbulence parameters that have a major impact on the astronomical optical imaging including atmospheric seeing, isoplanatic angle, coherence time, outer scale and turbulence profile, where turbulence profile is the distribution of atmospheric refractive index structure constant Cn2 with height, and it is the most basic parameters of atmospheric turbulence, the other parameters are associated with it.In this thesis, first of all, the atmospheric optical turbulence structures and the atmospheric optical turbulence parameters which have a major impact on the astronomical optical imaging were studied. Second, the principles of measuring atmospheric optical turbulence parameters which are based on single-edge and double-edge of moon are studied to recover medium resolution of the turbulence intensity profile by using the lateral wavefront angle-of-arrival fluctuations angular separation structure function and the differential angle separation correlation function. Third, several moon edge auto extraction algorithms were discussed, including the traditional edge detection algorithm and wavelet transform edge recognition algorithm. The calculating time needed and processing precision with different methods were analyzed. Fourth, several algorithm for linear inverse problems and nonlinear inverse problems were studied, including the non-negative least squares method, iterative gradient algorithm and simulated annealing algorithm. Finally, the experiments on single-edge and double-edge of moon for measuring turbulence profile were carried out, and preliminary measurement data were analyzed, demonstrating the feasibility of the data processing algorithms. The results obtained in this work is helpful for further improvement of the experimental protocol.