Research On Measurement Of Optital Parameters Of Atmospheric Turbulence Based Hartmann Wavefront Sensor

Atmospheric turbulence occupies a prominent position in effecting the laser beam. As the Hartmann wavefront sensor reconstructs the wave-front phase by measuring the wave-front slope, it is decided to be a broad application in the atmospheric turbulence parameter measurement.The basic knowledge of the turbulence statistical theory is introduced firstly in this paper. Based on the atmospheric refractive index models, as well as the refractive index fluctuation power spectral density and autocorrelation function, the specific refractive index structure function is got. Then the refractive index structure function and power spectrum characteristics of local isotropic turbulence is highlighted. Some of the commonly used spectral models of turbulence are described also. Based on spectral models of turbulence , Some of the measurement methods of optical parameters of atmospheric turbulence are discussed, with emphasis placed on the optical measurement methods using light propagation effects.In this paper, the composition of Hartmann wavefront sensor and the theory of optical measurement are described specifically. A variety of factors which effect centroid detection accuracy of the Hartmann wavefront sensor and the major source of measurement error are discussed as well. Then the basic theory of characterizing atmospheric turbulence by the Hartmann wavefront sensor is introduced. At last, a theoretical model of Hartmann wavefront sensor is established initially, which provides a convenient tool for the characterization of turbulent medium's characteristic parameters.