Lidar Measurement of Optical Turbulence: Theory of the Crossed Path Technique

Numerous studies have demonstrated the importance of obtaining the vertical distribution of turbulence in a timeefficient way for evaluating FSO systems and related laser applications, making it necessary to specify the profile of turbulence along the atmospheric propagation path. This paper presents a method for the rapid measurement of nearground turbulence profiles. This method is capable of providing a real-time evaluation of an optical propagation link, making it a useful tool for remote sensing of atmospheric turbulence. Based on this method, a turbulence profile LiDAR has been built in Hefei (31.8°N, 117.3°E) and long-term continuous measurements of the vertical distribution of turbulence were performed from October 2021 to November 2021. The retrieved results of turbulence profiles show that the LiDAR can describe spatiotemporal distributions of turbulence intensity along the measurement path corresponding to the weather and daily time changes.

show abstract

“…For the differential scintillation method based on the Cross-Path theory [9], the modified structure function ( )…”

Section: Methodsmentioning

confidence: 99%

Development of LiDAR for real-time measurement of near-ground turbulence profiles and its observation results

Qiu

Hou

et al. 2022

5th Optics Young Scientist Summit (OYSS 2022)

View full text Add to dashboard Cite

show abstract

“…As mentioned previously, most techniques for sensing C and thave relied upon measurements of optical scintillations [3,4,5]. Some other previous work has also explored the use of measurements of wave front phase to sense [7,8,9,10].…”

Section: Path Weighting Function Wc(z)mentioning

confidence: 99%

“…The output of wave front slope sensor n is a noisy measurement of the average slope of () across the sensor's aperture and is denoted s,. Wailner gives the expression for s,-as [11] Sn = f d2 W)q() + c. (3) where W,() is the gradient of the aperture weighting function W() in the wave front sensor's direction of sensitivity. The numeric results presented in this paper assume square wave front slope sensors, with the smaller sensor of dimension L1 and the larger sensor of dimension L2.…”

Section: Path Weighting Function Wc(z)mentioning

confidence: 99%

“…Likewise, anenometers cannot be placed at all the points necessary to obtain a good profile of 9 along an optical path. The usual remote sensing approach is to measure some effect of the atmosphere on a reference beam of light and relate the measured effect to C or V. Numerous techniques have been used to measure C and V [3,4,5]. Such techniques have become more practical with recent advances in the generation of artificial guide stars for use as reference sources [6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

<title>Remote sensing of atmospheric turbulence and transverse atmospheric winds using optical reference sources</title>

Koeffler

Welsh

1993

Atmospheric Propagation and Remote Sensing II

View full text Add to dashboard Cite

In the theory of atmospheric turbulence, the strength of the spatial variations of the index of refraction n is proportional to a parameter known as the atmospheric structure constant, denoted C, which is a function of position along the optical path z. The strength of the temporal variations of the index of refraction is directly related to the transverse velocity V of the turbulence along z. Current optical techniques for remotely sensing C and V rely primarily upon the spatial or temporal cross-correlation properties of the intensity of the optical field. In the technique proposed here, we exploit the correlation properties of the wave front slope measured from two different point sources in order to obtain vertical profiles of C(z) and V(z). Resolution on the order of 100 meters is possible with reference sources separated by 0.2 degrees.

show abstract

“…The methods are based on analysis of turbulence induced scintillation of LIDAR signals [14][15][16][17], image distortion and image motion of secondary sources produced by laser beam [18][19][20][21][22], and phenomena of enhanced backscattering [23,24].…”

Section: Introductionmentioning

confidence: 99%

Laser beam wander in the atmosphere: implications for optical turbulence vertical profile sensing with imaging LIDAR

Zilberman

Kopeika

2008

J. Appl. Remote Sens

View full text Add to dashboard Cite

A summary of different approaches for laser beam wander statistics estimation is presented. The principles of an imaging LIDAR technique for remote measurements of refractive turbulence vertical profile based on image motion analysis of a secondary source created by a laser beam at a given altitude are described. The turbulence-induced beam displacement statistics and angle-of-arrival variance of backscattered wave-front are analyzed for different sensing configurations. This study has implications for airborne reconnaissance image restoration, optical satellite communication, adaptive optics, and atmospheric effects on laser weaponry.

show abstract

Lidar Measurement of Optical Turbulence: Theory of the Crossed Path Technique

Cited by 5 publications

References 5 publications

Development of LiDAR for real-time measurement of near-ground turbulence profiles and its observation results

Development of LiDAR for real-time measurement of near-ground turbulence profiles and its observation results

<title>Remote sensing of atmospheric turbulence and transverse atmospheric winds using optical reference sources</title>

Laser beam wander in the atmosphere: implications for optical turbulence vertical profile sensing with imaging LIDAR

Contact Info

Product

Resources

About