An off-axis atmospheric turbulence intensity profile real-time measurement device and method

Abstract

The invention discloses an off-axis real-time measuring device and method for atmosphere turbulence intensity profile. The method comprises the following steps: adopting a solid-state laser as an emitting light source, focusing a laser beam into air to form Rayleigh laser beacon by using a large-caliber transmitting telescope in a beam expanding manner, receiving back scattering light at the beacon by a plurality of sets of off-axis receiving telescopes, dividing received light into two beams through a subsequent light path, forming a double facula image on a detector, summarizing the fluctuation of space between two facula mass centers, calculating the fluctuation variance of the difference arrival angle in the distance, then changing the distance of the distance beacon, calculating the fluctuation variance of the difference arrival angles in a plurality of distance, and finally calculating the atmosphere turbulence intensity profile through a certain inversion algorithm. The measuring device for atmosphere turbulence intensity profile not only can acquire the atmosphere turbulence intensity profile in real time, but also has the advantages that the measuring path is controllable, and the range resolution is high.

Description

technical field [0001] The invention belongs to the technical field of optical measuring instruments, and relates to an off-axis real-time measuring device and method for the intensity profile of atmospheric turbulence. Background technique [0002] When the laser beam is transmitted in the atmosphere, the fluctuation of the atmospheric refractive index caused by the fluctuation of the atmospheric density will cause the beam transmitted in it to produce beam drift, beam expansion, light intensity flicker, phase fluctuation and other effects, destroying the coherence of the laser beam, seriously Affects the propagation quality of the beam. In atmospheric optics research, the atmospheric turbulence intensity C n 2 It is a basic parameter to characterize the characteristics of atmospheric turbulence. The measured atmospheric turbulence intensity profile can describe the details of the turbulence in the atmosphere finely, thus providing basic parameters for the study of laser...

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Problems solved by technology

The temperature pulsation instrument sounding method uses the sounding balloon to hang the temperature pulsation instrument for sounding measurement. This method has high spatial resolution, but because the balloon is affected by the wind, the measurement path is not controlled. In addition, the measurement of a profile The line time is also longer

Microwave radar calculates the intensity of atmospheric turbulence by measuring the backscattering power of the radar signal, but it needs to provide the temperature and humidity on the path, which is time-consuming, and the influence of humidity on the measurement is difficult to deduct, so the accuracy is not high

The measurement principle of sodar is similar to that of microwave radar, but because sound waves are mechanical waves, they can only measure the atmospheric boundary layer, and due to the limitation of sound power, the measurement height is limited

The SCIDAR method obtains the intensity profile of atmospheric turbulence by detecting the correlation of light intensity or phase distribution on a certain area, but requires two light sources separated by a certain distance as beacons, the requirements for beacons are more stringent, and the telescope aperture is required to be larger. Generally above 1m, which brings great restrictions to its application

MASS is a low-resolution atmospheric turbulence intensity profile measurement device, which can only give atmospheric turbulence intensity values ​​at 6 to 7 distances, with low spatial resolution

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