CN103424380B - A kind of from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method - Google Patents

Abstract

The invention discloses a kind of employing from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method, adopt solid state laser as transmitting illuminant, utilize heavy caliber transmitter-telescope laser beam to be expanded and focus on aerial formation Rayleigh laser beacon, receive from the rear orientation light of shaft type receiving telescope to beacon by overlapping more, by follow-up light path, the light received is divided into two bundles, forms two light spot image on the detector.The fluctuating of statistics two facula mass center spacing calculates the difference arrival angle fluctuation variance of this distance, change the distance focusing on beacon again, calculate the difference arrival angle fluctuation variance of multiple distance successively, calculate atmospheric turbulence intensity profile finally by certain inversion algorithm.This atmospheric turbulence intensity profile measurement mechanism can not only obtain atmospheric turbulence intensity profile in real time, and it is controlled to have measuring route, the advantage that range resolution is high.

Description

A kind of from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method

Technical field

The invention belongs to optical gauge technical field, relate to a kind of from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method.

Background technology

When laser beam is transmitted in an atmosphere, air index fluctuating caused by atmospheric density rises and falls can make the light beam transmitted produce the effects such as beam drift, beam spread, light intensity flicker, phase fluctuation wherein, destroy the coherence of laser beam, have a strong impact on the propagation quality of light beam.In atmospheric optics research, atmospheric turbulence intensity C _n ²it is the basic parameter characterizing atmospheric turbulence characteristic.Measure the atmospheric turbulence intensity profile obtained, the details of turbulent flow in air can be described subtly, thus provide basic parameter for Laser Atmospheric Transmission effect study.

At present, the method for measurement of Atmospheric Turbulence intensity profile has: micro-temperature sensor sounding method, microwave radar, acoustic radar and optical means (SCIDAR, MASS).Micro-temperature sensor sounding method adopts sounding balloon hanging micro-temperature sensor to carry out sounding measurement, and this method has very high spatial resolution, but due to the impact of balloon wind-engaging, measuring route is uncontrolled, and in addition, the time of measuring a profile is also longer.Microwave radar by the back scattering power calculation atmospheric turbulence intensity of instrumentation radar signal, but needs the temperature and humidity that provides on path, more time-consuming, and humidity is difficult to deduction, so precision is not high yet to the impact of measuring.Acoustic radar measuring principle and microwave radar similar, but due to sound wave be mechanical wave, can only atmospheric boundary layer be measured, and due to the restriction of acoustical power, make measuring height limited.SCIDAR method is by detecting the correlativity of light intensity or PHASE DISTRIBUTION on certain area, obtain atmospheric turbulence intensity profile, but require that two light sources kept at a certain distance away are as beacon, comparatively harsh to the requirement of beacon, and require that telescope bore is larger, general at more than 1m, bring very large restriction to its application.MASS is a kind of atmospheric turbulence intensity profile measurement mechanism of low resolution, and can only provide the atmospheric turbulence intensity value of 6 to 7 distances, spatial resolution is low.

Summary of the invention

The problem that the present invention solves is to provide a kind of from shaft type atmospheric turbulence intensity profile measurement mechanism and measuring method, can not only obtain atmospheric turbulence intensity profile in real time, and it is controlled to have measuring route, the advantage that range resolution is high.

The present invention is achieved through the following technical solutions:

A kind of from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, comprise laser instrument, the laser beam that laser instrument is launched enters transmitter-telescope after catoptron, laser beam is emitted to flat reflective mirror after being expanded by transmitter-telescope, beam reflection focuses on to aerial setpoint distance by flat reflective mirror, forms laser beacon; Received by the rear orientation light of flat reflective mirror to laser beacon and reflex to from shaft type receiving telescope, the light that receiving telescope receives is reflected by triangular prism and enters follow-up light path, follow-up light path transfers in photodetector by after light beam light splitting, photodetector is by the light beam imaging of reception and light signal is converted to electric signal, electric signal through the collection of data acquisition and procession unit, be converted to digital signal, after the laser beacon image at different distance place, space is processed, calculate atmospheric turbulence intensity profile.

The described laser instrument laser beam of launching enters in transmitter-telescope via after the parallel catoptron reflection of two light paths.

Described transmitter-telescope is Schmidt-Ka Sai Green formula structure, comprise secondary mirror and primary mirror, laser beam is expanded by secondary mirror and reflexes to primary mirror, then by primary mirror focus emission, the laser beam of primary mirror focus emission is after the reflection of flat reflective mirror, and aloft preset distance place focuses on.

The described spacing by regulating in transmitter-telescope between secondary mirror and primary mirror, the laser beam of primary mirror focus emission is after the reflection of flat reflective mirror, and aloft different distance place focuses on, and forms Rayleigh laser beacon.

The angle of pitch of described flat reflective mirror according to optical path adjusting, can make the direction transmission along setting after the reflection of flat reflective mirror of the laser beam of primary mirror focus emission.

Described receiving telescope comprises convex mirror, catoptron and ellipsoid concave mirror, ellipsoid concave mirror by the beam reflection that reflected by flat reflective mirror to convex mirror, convex mirror is by beam reflection to catoptron, and catoptron is by beam reflection to triangular prism, and triangular prism is by beam reflection to follow-up light path.

Described receiving telescope is by the symmetrical receiving telescope system formed from shaft type receiving telescope of many covers; Often overlap the light beam that receives from shaft type receiving telescope after follow-up light path, all each comfortable photodetector of its laser beacon received forms light spot image.

Described follow-up light path comprises the first convex lens group, optical filter, wedge and the second convex lens group, the light beam entered in follow-up light path is collimated by the first convex lens group, by optical filter filtering light beam parasitic light, through wedge, light beam is divided into two bundles, finally by the second convex lens group, light beam is converged in photodetector.

Described transmitter-telescope and receive telescope from shaft type and be arranged on the turntable that the angle of pitch and position angle can regulate, and transmitter-telescope is parallel with the optical axis of receiving telescope, receiving telescope can receive the rear orientation light of the laser beacon formed at setpoint distance place, space after transmitter-telescope is launched.

From a shaft type atmospheric turbulence intensity profile method for real-time measurement, comprise following operation:

1) laser instrument is launched N number of laser pulse light beam and is focused on distance h ₁place forms laser beacon, received the rear orientation light of laser beacon from shaft type receiving telescope by two covers, photodetector is formed two hot spot, then photodetector gather become N two field picture, every two field picture is calculated respectively to the barycenter of two hot spots, if the barycenter distance of two of the i-th two field picture hot spots is b _i, the focal length of receiving telescope system is f ₀, then distance h ₁the difference arrival angle fluctuation variance of place's laser beacon light beam is calculated by following formula and provides:

${\mathrm{\σ}}_{\mathrm{DIM}}^2\left(h_1\right)=\frac{\stackrel{\‾}{B_i^2}-{\stackrel{\‾}{B_i}}^2}{f_0^2}$

$\stackrel{\‾}{B_i^2}=\left(\mathrm{\Σ}{b_i}^2\right)/N$ $\stackrel{\‾}{B_i^2}={(\mathrm{\Σ}{b}_i/N)}^2---\left(1\right)$

2) then regulate transmitter-telescope, focus of the light beam into distance h respectively ₂, h ₃, h ₄..., h _nplace, calculates according to the method for step 1) and provides laser beacon distance for h ₂, h ₃, h ₄..., h _nthe difference arrival angle fluctuation variance of place's light beam;

3) for spherical wave, the relation of difference arrival angle fluctuation variance and atmospheric turbulence intensity is shown below:

${\mathrm{\σ}}_{\mathrm{DIM}}^2\left(h\right)=33.2({{0.358d}_0}^{-1/3}-{{0.242d}_s}^{-1/3}){\∫}_0^h{C}_n^2\left(h^{\′}\right){(1-h^{\′}/h)}^{5/3}{\mathrm{dh}}^{\′}---\left(2\right)$

Wherein d ₀for the sub-pupil diameter of receiving telescope, d _sfor the spacing at receiving telescope Liang Gezitong center, C _n ²h () is the atmospheric turbulence intensity at distance h place;

C (h) is utilized to represent C _n ²(h), and define M (h) and be:

$M\left(h\right)={\∫}_0^{h}C\left(h^{\′}\right){(1-h^{\′}/h)}^{5/3}{\mathrm{dh}}^{\′}---\left(3\right)$

Wherein M (h) and difference arrival angle fluctuation variances sigma _dIM ²difference be only a constant factor κ, so the difference arrival angle fluctuation variance of each distance measured by utilization can calculate and provide M (h).Finally, atmospheric turbulence intensity profile can be obtained by M (h) inverting C (h);

Due to the instability utilizing M (h) direct inversion C (h) can bring numerical solution, acquired results is also insincere, so, first formula (3) is out of shape at this, then solves again.Differentiate to formula (3) both sides, the pass of derivative S (h) and C (h) that can obtain M (h) is:

$S\left(h\right)={\∫}_0^{h}C\left(h^{\′}\right)\left[\frac{5}{3}\frac{h^{\′}}{h^2}{(1-\frac{h^{\′}}{h})}^{2/3}\right]{\mathrm{dh}}^{\′}---\left(4\right)$

Suppose can be approximately constant at each distance segment C (h), namely

C(h)=C _jh _j-1<h<h _j(5)

(4) in formula, each parameter is continuous variable, carries out discretize, provide distance h to (4) formula _ithe discrete expression at place M (h) slope S (h) is:

$S_i=\underset{j=1}{\overset{i}{\mathrm{\&Sigma;}}}{C}_j{\&Integral;}_{h_{j-1}}^{h_j}\left[\frac{5}{3}\frac{h^{\&prime;}}{h_i^2}{(1-\frac{h^{\&prime;}}{h_i})}^{2/3}\right]{\mathrm{dh}}^{\&prime;}---\left(6\right)$

As j≤i, the integration in above formula is:

$U_{\mathrm{ij}}={[\frac{3}{8}-(\frac{3}{8}+\frac{5}{8}\frac{h^{\&prime;}}{h_i}){(1-\frac{h^{\&prime;}}{h_i})}^{5/3}]}_{h^{\&prime;}=h_{j-1}}^{h^{\&prime;}=h_j}---\left(7\right)$

As j>i, U _ijvalue is zero, and (6) formula is expressed as:

$S_i=\underset{j=1}{\overset{i}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j=\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j---\left(8\right)$

Its inverse matrix is asked to formula (6), can obtain:

$C_i=\frac{1}{U_{\mathrm{ii}}}(S_i-\underset{j=1}{\overset{i-1}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j)---\left(9\right)$

Utilize above formula to C _icarry out ascending order to solve, atmospheric turbulence intensity C can be obtained _iprofile value.

Compared with prior art, the present invention has following useful technique effect:

Provided by the invention from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method, adopt solid state laser as transmitting illuminant, utilize heavy caliber transmitter-telescope laser beam to be expanded and focus on aerial formation Rayleigh laser beacon, receive from the rear orientation light of shaft type receiving telescope to beacon by overlapping more, by follow-up light path, the light received is divided into two bundles, forms two light spot image on the detector.The fluctuating of statistics two facula mass center spacing calculates the difference arrival angle fluctuation variance of this distance, change the distance focusing on beacon again, calculate the difference arrival angle fluctuation variance of multiple distance successively, calculate atmospheric turbulence intensity profile finally by certain inversion algorithm.This atmospheric turbulence intensity profile measurement mechanism can not only obtain atmospheric turbulence intensity profile in real time, and it is controlled to have measuring route, the advantage that range resolution is high.

Provided by the invention from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method, use two small-sizedly to form differential received system from shaft type telescope.Make system more portable and smart, reduce cost.Simultaneously two small-sizedly form coaxial system from shaft type telescope and transmitter-telescope, are conducive to the adjustment of light path.

Existing beam control system directly controls the pitching of transmitter-telescope to control the elevation angle of transmitted beam, makes beam control system too huge.And the present invention uses flat reflective mirror to control the sensing of light beam, simplify control system.

Provided by the invention from shaft type atmospheric turbulence intensity profile real-time measurement apparatus and method, Measuring Time is unrestricted, and measuring route is adjustable flexibly, and range resolution is high, can measure the atmospheric turbulence intensity profile of desired path at any time; Adopt the computing method based on spherical wave, and construct slope matrix inverting atmospheric turbulence intensity, algorithmic stability, the data obtained are more genuine and believable.

Accompanying drawing explanation

Fig. 1 is the structural representation from shaft type atmospheric turbulence intensity profile real-time measurement apparatus.

Wherein: 1 be optical table, 2 be laser instrument, 3 be transmitter-telescope, 4 be receiving telescope, 5 be flat reflective mirror, 6 be follow-up light path, 7 for photodetector.

8 is catoptron, and 9 is secondary mirror, and 10 is primary mirror.

11 is convex mirror, and 12 is catoptron, and 13 is ellipsoid concave mirror.

14 is triangular prism, and 15 is convex lens, and 16 is optical filter, and 17 is wedge, and 18 is convex lens.

19 is data acquisition and procession unit.

Embodiment

Below in conjunction with specific embodiment, the present invention is described in further detail, and the explanation of the invention is not limited.

See Fig. 1, a kind of from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, comprise laser instrument 2, the laser beam that laser instrument 2 is launched enters transmitter-telescope 3 after catoptron 8, laser beam is emitted to flat reflective mirror 5 after being expanded by transmitter-telescope 3, beam reflection focuses on to aerial setpoint distance place by flat reflective mirror 5, forms laser beacon; Received by the rear orientation light of flat reflective mirror 5 pairs of laser beacons and reflex to from shaft type receiving telescope 4, the light that receiving telescope 4 receives is reflected by triangular prism 14 and enters follow-up light path 6, follow-up light path 6 will transfer in photodetector 7 after light beam light splitting, photodetector 7 is by the light beam imaging of reception and light signal is converted to electric signal, electric signal gathers through data acquisition and procession unit 19, is converted to digital signal, after the laser beacon image at different distance place, space is processed, calculate atmospheric turbulence intensity profile.

Concrete, laser instrument 2 adopts solid Nd: YAG laser, and its centre wavelength exported is 532nm, exports single pulse energy 300mJ, repetition frequency 50Hz.The laser beam laser beam that laser instrument 2 is launched is launched by the catoptron 8 that two light paths are parallel and is entered in transmitter-telescope 3.

And transmitter-telescope 3 is Schmidt-Ka Sai Green formula structure, comprise secondary mirror 9 and primary mirror 10, laser beam is expanded by secondary mirror 9 and reflexes to primary mirror 10, then by primary mirror 10 focus emission, the laser beam of primary mirror 10 focus emission is after flat reflective mirror 5 reflects, and aloft preset distance place focuses on.

By regulating the spacing in transmitter-telescope 3 between secondary mirror 9 and primary mirror 10, the laser beam of primary mirror 10 focus emission is after flat reflective mirror 5 reflects, and aloft different distance place focuses on, and forms Rayleigh laser beacon.Like this when measuring, transmitter-telescope major-minor mirror spacing can be regulated according to sampled distance, making to focus at preset distance place to form Rayleigh laser beacon.

The angle of pitch of described flat reflective mirror 5 according to optical path adjusting, can make the direction transmission along setting after flat reflective mirror 5 reflects of the laser beam of primary mirror 10 focus emission.

The Rayleigh laser beacon rear orientation light formed in a distance, space by flat reflective mirror 5 pairs of focus emission laser beam receives and reflexes in receiving telescope 4.Described receiving telescope 4 comprises convex mirror 11, catoptron 12 and ellipsoid concave mirror 13, ellipsoid concave mirror 13 by the beam reflection that reflected by flat reflective mirror 5 to convex mirror 11, convex mirror 11 by beam reflection to catoptron 12, catoptron 12 is by beam reflection to triangular prism 14, and triangular prism 14 is by beam reflection to follow-up light path 6.Follow-up light path 6 comprises the first convex lens group 15, optical filter 16, wedge 17 and the second convex lens group 18, the light beam entered in follow-up light path 6 is collimated by the first convex lens group 15, by optical filter 16 filtering light beam parasitic light, through wedge 17, light beam is divided into two bundles, finally converge in photodetector 7 by the second convex lens group 18 by light beam, described photodetector 7 is image intensifying type CCD camera.

Further, described receiving telescope 4 is by the symmetrical receiving telescope system formed from shaft type receiving telescope of many covers; Often overlap the light beam that receives from shaft type receiving telescope after follow-up light path 6, all each comfortable photodetector 7 of its laser beacon received forms light spot image.

Such as on photodetector 7, forms pair light spot image by the laser beacon received from the receiving telescope system 4 of shaft type receiving telescope that two covers are symmetrical.Except by except symmetrical receiving telescope system form from shaft type receiving telescope of two covers, it also can be the receiving telescope system formed from shaft type receiving telescope of the symmetry of three covers, four covers or more; Now, the laser beacon received forms three light spot images, the more light spot image of four light spot images on photodetector 7.

When measuring, first the sampling frame number of sampled distance and each distance is set.Namely regulate transmitter-telescope major-minor mirror spacing according to sampled distance after setting completed, make to focus at preset distance place to form Rayleigh laser beacon, control laser instrument immediately and make laser instrument bright dipping.After first distance completes the sampling of certain frame number, then regulate transmitter-telescope to focus of the light beam into the sampling of next distance, calculate the difference arrival angle fluctuation variance of first distance simultaneously according to the signal gathering gained.Measuring distance is h successively ₃, h ₄..., h _ndeng the light spot image at place, and calculating provides distance h ₃, h ₄..., h _ndeng the difference arrival angle fluctuation variance at place.Obtain n difference arrival angle fluctuation variance data after complete to n distance samples, process is carried out to these data and can obtain atmospheric turbulence intensity profile.

Provide from shaft type atmospheric turbulence intensity profile method for real-time measurement below, laser instrument sends pulsed light beam and expands focusing by transmitter-telescope and reflect through flat reflective mirror, Rayleigh laser beacon is formed at preset distance place, beacon rear orientation light is after flat reflective mirror, be incident to from shaft type receiving telescope, receiving telescope is by beam Propagation extremely follow-up light path, by follow-up light path, light beam is filtered, transfer to detector after beam splitting and form two light spot image, by the fluctuating of the two facula mass center distance of data Collection & Processing System statistics multiple image, calculate the difference arrival angle fluctuation variance at testing distance place, then focus of the light beam into next distance to measure, successively above-mentioned identical operation is carried out to each measuring distance, after obtaining difference arrival angle fluctuation variance profile data, and then the data inversion of difference arrival angle fluctuation variance profile is utilized to calculate atmospheric turbulence intensity profile value.Specifically comprise following operation:

1) laser instrument is launched N number of laser pulse light beam and is focused on h ₁distance forms laser beacon, received the rear orientation light of laser beacon from shaft type receiving telescope by two covers, photodetector is formed two hot spot, then photodetector gather become N two field picture, every two field picture is calculated respectively to the barycenter of two hot spots, if the barycenter distance of two of the i-th two field picture hot spots is b _i, the focal length of receiving telescope system is f ₀, then distance h ₁the difference arrival angle fluctuation variance of place's laser beacon light beam is calculated by following formula and provides:

${\mathrm{\&sigma;}}_{\mathrm{DIM}}^2\left(h_1\right)=\frac{\stackrel{\&OverBar;}{B_i^2}-{\stackrel{\&OverBar;}{B_i}}^2}{f_0^2}$

$\stackrel{\&OverBar;}{B_i^2}=\left(\mathrm{\&Sigma;}{b_i}^2\right)/N$ $\stackrel{\&OverBar;}{B_i^2}={(\mathrm{\&Sigma;}{b}_i/N)}^2---\left(1\right)$

2) then regulate transmitter-telescope, focus of the light beam into h respectively ₂, h ₃, h ₄..., h _nequidistant, calculates according to the method for step 1) and provides laser beacon distance for h ₂, h ₃, h ₄..., h _ndeng the difference arrival angle fluctuation variance of place's light beam;

3) for spherical wave, the relation of difference arrival angle fluctuation variance and atmospheric turbulence intensity is shown below:

${\mathrm{\&sigma;}}_{\mathrm{DIM}}^2\left(h\right)=33.2({{0.358d}_0}^{-1/3}-{{0.242d}_s}^{-1/3}){\&Integral;}_0^h{C}_n^2\left(h^{\&prime;}\right){(1-h^{\&prime;}/h)}^{5/3}{\mathrm{dh}}^{\&prime;}---\left(2\right)$

Wherein d ₀for the sub-pupil diameter of receiving telescope, d _sfor the spacing at receiving telescope Liang Gezitong center, C _n ²h () is the atmospheric turbulence intensity at distance h place, h ' is integration variable;

C (h) is utilized to represent C _n ²(h), and define M (h) and be:

$M\left(h\right)={\&Integral;}_0^{h}C\left(h^{\&prime;}\right){(1-h^{\&prime;}/h)}^{5/3}{\mathrm{dh}}^{\&prime;}---\left(3\right)$

Wherein M (h) and difference arrival angle fluctuation variances sigma _dIM ²difference be only a constant factor κ, so the difference arrival angle fluctuation variance of each distance measured by utilization can calculate and provide M (h).Finally, atmospheric turbulence intensity profile can be obtained by M (h) inverting C (h);

Due to the instability utilizing M (h) direct inversion C (h) can bring numerical solution, acquired results is also insincere, so, first formula (3) is out of shape at this, then solves again.Differentiate to formula (3) both sides, the pass of derivative S (h) and C (h) that can obtain M (h) is:

$S\left(h\right)={\&Integral;}_0^{h}C\left(h^{\&prime;}\right)\left[\frac{5}{3}\frac{h^{\&prime;}}{h^2}{(1-\frac{h^{\&prime;}}{h})}^{2/3}\right]{\mathrm{dh}}^{\&prime;}---\left(4\right)$

Suppose can be approximately constant at each distance segment C (h), namely

C(h)=C _jh _j-1<h<h _j(5)

C _jfor distance segment h _j-1<h<h _jthe value of atmospheric turbulence intensity;

(4) in formula, each parameter is continuous variable, carries out discretize, provide distance h to (4) formula _ithe discrete expression at place M (h) slope S (h) is:

$S_i=\underset{j=1}{\overset{i}{\mathrm{\&Sigma;}}}{C}_j{\&Integral;}_{h_{j-1}}^{h_j}\left[\frac{5}{3}\frac{h^{\&prime;}}{h_i^2}{(1-\frac{h^{\&prime;}}{h_i})}^{2/3}\right]{\mathrm{dh}}^{\&prime;}---\left(6\right)$

As j≤i, the integration in above formula is:

$U_{\mathrm{ij}}={[\frac{3}{8}-(\frac{3}{8}+\frac{5}{8}\frac{h^{\&prime;}}{h_i}){(1-\frac{h^{\&prime;}}{h_i})}^{5/3}]}_{h^{\&prime;}=h_{j-1}}^{h^{\&prime;}=h_j}---\left(7\right)$

As j>i, U _ijvalue is zero, and (6) formula is expressed as:

$S_i=\underset{j=1}{\overset{i}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j=\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j---\left(8\right)$

Its inverse matrix is asked to formula (6), can obtain:

$C_i=\frac{1}{U_{\mathrm{ii}}}(S_i-\underset{j=1}{\overset{i-1}{\mathrm{\&Sigma;}}}{U}_{\mathrm{ij}}{C}_j)---\left(9\right)$

Utilize above formula to C _icarry out ascending order to solve, atmospheric turbulence intensity C can be obtained _iprofile value.

Said method adopts the computing method based on spherical wave, and constructs slope matrix inverting atmospheric turbulence intensity, and the data obtained are more genuine and believable.

Claims (7)

1. one kind from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, it is characterized in that, comprise laser instrument (2), the laser beam that laser instrument (2) is launched enters transmitter-telescope (3) after catoptron (8), laser beam is emitted to flat reflective mirror (5) after being expanded by transmitter-telescope (3), beam reflection focuses on to aerial setpoint distance place by flat reflective mirror (5), forms laser beacon, received by flat reflective mirror (5) rear orientation light to laser beacon and reflex in receiving telescope (4), the light that receiving telescope (4) receives is reflected by triangular prism (14) and enters follow-up light path (6), follow-up light path (6) will transfer in photodetector (7) after light beam light splitting, photodetector (7) is by the light beam imaging of reception and light signal is converted to electric signal, electric signal gathers through data acquisition and procession unit (19), be converted to digital signal, after the laser beacon image at different distance place, space is processed, Inversion Calculation atmospheric turbulence intensity profile,

Described laser instrument (2) laser beam of launching is via entering in transmitter-telescope (3) after parallel catoptron (8) reflection of two light paths;

Described transmitter-telescope (3) is Schmidt-Ka Sai Green formula structure, comprise secondary mirror (9) and primary mirror (10), laser beam is expanded by secondary mirror (9) and reflexes to primary mirror (10), again by primary mirror (10) focus emission, the laser beam of primary mirror (10) focus emission is after flat reflective mirror (5) reflection, aloft preset distance place focuses on, and forms laser beacon;

Described receiving telescope (4) comprises convex mirror (11), catoptron (12) and ellipsoid concave mirror (13), the beam reflection that ellipsoid concave mirror (13) will be reflected by flat reflective mirror (5) is to convex mirror (11), convex mirror (11) by beam reflection to catoptron (12), catoptron (12) is by beam reflection to triangular prism (14), and triangular prism (14) is by beam reflection to follow-up light path (6);

Described receiving telescope (4) is by the symmetrical receiving telescope system formed from shaft type receiving telescope of many covers; Often overlap the light beam that receives from shaft type receiving telescope after follow-up light path (6), all each comfortable photodetector (7) of its laser beacon received forms light spot image.

2. as claimed in claim 1 from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, it is characterized in that, by regulating the spacing in transmitter-telescope (3) between secondary mirror (9) and primary mirror (10), the laser beam of primary mirror (10) focus emission is after flat reflective mirror (5) reflection, aloft different distance place focuses on, and forms laser beacon.

3. as claimed in claim 1 from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, it is characterized in that, the angle of pitch of described flat reflective mirror (5) can regulate as required, make the direction transmission along setting after flat reflective mirror (5) reflection of the laser beam of primary mirror (10) focus emission, make the rear orientation light of laser beacon enter receiving telescope after flat reflective mirror (5) reflection, and launch light path with receiving light path along identical transmission path.

4. as claimed in claim 1 from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, it is characterized in that, described follow-up light path (6) comprises the first convex lens group (15), optical filter (16), wedge (17) and the second convex lens group (18), the light beam entered in follow-up light path (6) is collimated by the first convex lens group (15), by optical filter (16) filtering light beam parasitic light, through wedge (17), light beam is divided into two bundles, finally by the second convex lens group (18), light beam is converged in photodetector (7).

5. as claimed in claim 1 from shaft type atmospheric turbulence intensity profile real-time measurement apparatus, it is characterized in that, transmitter-telescope (3) and receiving telescope (4) are arranged on the turntable that the angle of pitch and position angle can regulate, and transmitter-telescope (3) is parallel with the optical axis of receiving telescope (4), receiving telescope (4) can receive the rear orientation light of the laser beacon formed at setpoint distance place, space after transmitter-telescope (3) is launched.

6. it is characterized in that from shaft type atmospheric turbulence intensity profile real-time measurement apparatus as claimed in claim 1, described photodetector (7) is image intensifying CCD camera or electron multiplication CCD camera, and sample frame speed is not less than 50fps.

7., from a shaft type atmospheric turbulence intensity profile method for real-time measurement, it is characterized in that, comprise following operation:

1) laser instrument is launched N number of laser pulse light beam and is focused on distance h ₁place forms laser beacon, received the rear orientation light of laser beacon from shaft type receiving telescope by two covers, photodetector is formed two hot spot, then photodetector gather become N two field picture, every two field picture is calculated respectively to the barycenter of two hot spots, if the barycenter distance of two of the i-th two field picture hot spots is b _i, the focal length of receiving telescope system is f ₀, then distance h ₁the difference arrival angle fluctuation variance of place's laser beacon light beam is calculated by following formula and provides:

${\mathrm{\&sigma;}}_{DIM}^2\left(h_1\right)=\frac{\stackrel{\&OverBar;}{B_i^2}-{\stackrel{\&OverBar;}{B_i}}^2}{f_0^2}$

$\begin{array}{cc}\stackrel{\&OverBar;}{B_i^2}=\left({{\mathrm{\&Sigma;b}}_i}^2\right)/N& {\stackrel{\&OverBar;}{B_i}}^2={({\mathrm{\&Sigma;b}}_i/N)}^2\end{array}---\left(1\right)$

2) then regulate transmitter-telescope, focus of the light beam into distance h respectively ₂, h ₃, h ₄..., h _nplace, according to step 1) method calculate and provide laser beacon distance for h ₂, h ₃, h ₄..., h _nthe difference arrival angle fluctuation variance of place's light beam;

3) for spherical wave, the relation of difference arrival angle fluctuation variance and atmospheric turbulence intensity is shown below:

${\mathrm{\&sigma;}}_{DIM}^2\left(h\right)=33.2(0.358{d_0}^{-1/3}-0.242{d_s}^{-1/3}){\&Integral;}_0^h{C}_n^2\left(h^{\&prime;}\right){(1-h^{\&prime;}/h)}^{5/3}{\mathrm{dh}}^{\&prime;}---\left(2\right)$

Wherein d ₀for the sub-pupil diameter of receiving telescope, d _sfor the spacing at receiving telescope Liang Gezitong center, C _n ²h () is the atmospheric turbulence intensity at distance h place; H ' is integration variable;

C (h) is utilized to represent C _n ²(h), and define M (h) and be:

$M\left(h\right)={\&Integral;}_0^{h}C\left(h^{\&prime;}\right){(1-h^{\&prime;}/h)}^{5/3}{\mathrm{dh}}^{\&prime;}---\left(3\right)$

Wherein M (h) and difference arrival angle fluctuation variances sigma _dIM ²difference be only a constant factor κ, the difference arrival angle fluctuation variance of each distance measured by utilization calculates and provides M (h), then obtains atmospheric turbulence intensity profile by M (h) inverting C (h);

First be out of shape formula (3) at this, then solve again, differentiate to formula (3) both sides, the pass of derivative S (h) and C (h) that obtain M (h) is:

$S\left(h\right)={\&Integral;}_0^{h}C\left(h^{\&prime;}\right)\&lsqb;\frac{5}{3}\frac{h^{\&prime;}}{h^2}{(1-\frac{h^{\&prime;}}{h})}^{2/3}\&rsqb;{\mathrm{dh}}^{\&prime;}---\left(4\right)$

Be located at each distance segment C (h) and be approximately constant, namely

C(h)＝C _jh _j-1<h<h _j(5)

Wherein, C _jfor distance segment h _j-1<h<h _jthe value of atmospheric turbulence intensity;

(4) in formula, each parameter is continuous variable, carries out discretize, provide distance h to (4) formula _ithe discrete expression at place M (h) slope S (h) is:

$S_i=\underset{j=1}{\overset{i}{\&Sigma;}}{C}_j{\&Integral;}_{h_{j-1}}^{h_j}\&lsqb;\frac{5}{3}\frac{h^{\&prime;}}{h_i^2}{(1-\frac{h^{\&prime;}}{h_i})}^{2/3}\&rsqb;{\mathrm{dh}}^{\&prime;}---\left(6\right)$

As j≤i, the integration in above formula is:

$U_{ij}={\&lsqb;\frac{3}{8}-(\frac{3}{8}+\frac{5}{8}\frac{h^{\&prime;}}{h_i}){(1-\frac{h^{\&prime;}}{h_i})}^{5/3}\&rsqb;}_{h^{\&prime;}=h_{j-1}}^{h^{\&prime;}=h_j}---\left(7\right)$

As j>i, U _ijvalue is zero, and (6) formula is expressed as:

$S_i=\underset{j=1}{\overset{i}{\&Sigma;}}{U}_{ij}{C}_j=\underset{j=1}{\overset{n}{\&Sigma;}}{U}_{ij}{C}_j---\left(8\right)$

Its inverse matrix is asked to formula (6), can obtain:

$C_i=\frac{1}{U_{ii}}(S_i-\underset{j=1}{\overset{i-1}{\&Sigma;}}{U}_{ij}{C}_j)---\left(9\right)$

(9) formula of utilization is to C _icarry out ascending order to solve, obtain atmospheric turbulence intensity C _iprofile value.