Differential light beam image motion and scintillation laser radar turbulence profile real-time measuring method

Abstract

The invention discloses a differential light beam image motion and scintillation laser radar turbulence profile real-time measuring method. According to physical laws that intensity scintillation is sensitive to the intensity of atmospheric turbulence at a beacon end, and beam jitter is sensitive to turbulence at a receiving end, the invention adopts a method for carrying out simultaneous statistics on intensity scintillation and beam jitter information of a laser beacon obtained after passing through atmosphere; through differentiate operation, a pair of parameters sensitive to the beacon-end turbulence and the receiving-end turbulence can be obtained; and therefore, influence of laser upward transmission, apparatus jitter or inherent scintillation of laser on measurement can be eliminated, and interference of turbulence randomicity on measurement is reduced. On the basis above, the method adopts a double-exponential model of turbulence intensity to describe finite-height turbulence intensity height distribution; according to physical meanings of each exponential term in the model, experience statistical value of coefficient of one exponential term is adopted, and inversion is carried out in real time to obtain coefficient of another exponential term; and through real-time-measurement differential flutter and differential scintillation exponential term coefficient inversion, turbulence intensity height distribution data can be obtained in real time.

Description

technical field [0001] The invention relates to the field of turbulent flow profile measurement methods, in particular to a method for real-time measurement of turbulent flow profile by differential beam image movement and scintillation laser radar. Background technique [0002] At present, an advanced method to obtain the turbulence profile of the whole layer in real time is to use the differential column image motion lidar together with the equihalation angle measuring instrument, and use the differential column image motion lidar to image the laser beam at a height range of several kilometers and extract the beam The atmospheric coherence length profile is obtained from the differential jitter information of the star, and the iso-halo angle is obtained by measuring the scintillation effect of the star after passing through the atmosphere with the iso-halo angle measuring instrument, and the refractive index structure constant profile is obtained by combining the three-expo...

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Problems solved by technology

However, its deficiencies or needs to be improved are also obvious: First, the existing differential beam radar needs to image the laser beam in a large height range, and must adopt a paraxial structure design, so the distance between the radar transmitting and receiving systems is relatively large, and the instrument too large

Secondly, the existing differential column image motion radar only extracts the beam jitter information of the turbulence effect after the laser beam passes through the atmosphere. The beam jitter is sensitive to low-altitude turbulence but not to high-altitude turbulence, and the error of directly using the jitter data to invert the turbulence profile is relatively large. ;In order to improve the measurement accuracy, the flicker effect of light intensity sensitive to high-altitude turbulence in the system is obtained by observing the stars through the equihalation angle measuring instrument. Therefore, this measurement method requires the cooperation of two sets of equipment, which is complex in design and inconvenient to use

Finally, if there are thin clouds in the sky and the halo angle measuring instrument fails to work, the system cannot effectively give the turbulence profile at a limited distance, and cannot carry out research work on the change law of the turbulence intensity profile in cloudy weather, which limits the application of the radar system

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