Atmospheric turbulence high-resolution profile detection laser radar system device and detection method

Abstract

The invention discloses an atmospheric turbulence high-resolution profile detection laser radar system device and a detection method. The method comprises the steps that a pulse laser emits a pulse laser beam to the atmosphere; atmospheric turbulence at different positions on a laser path disturbs the amplitude and the phase of the light wave, and a back scattering light spot carrying disturbance information reaches a double-hole telescope at a receiving end; respectively imaging through double apertures of the double-aperture telescope, modulating each image point by a light intensity modulator in the subsequent light calculation centroid detection unit according to a fixed mode, and carrying out correlation operation on a detected light intensity value and a modulation signal by the subsequent light calculation centroid detection unit to obtain light spot centroid distribution at different path positions; and a certain number of laser pulses are emitted accumulatively, the light spot mass center jitter variance at the corresponding position is calculated, and the atmosphere turbulence distribution profile information on the path through which the laser passes is obtained. According to the invention, high-precision and high-temporal-spatial-resolution detection research on the atmospheric coherence length and refractive index structure constant profile is realized.

Description

Technical Field

[0001] The present invention relates to the field of atmospheric optics and climate environment monitoring technology, and in particular to an atmospheric turbulence high-resolution profile detection laser radar system device and detection method. Background Art

[0002] Atmospheric turbulence intensity (the atmospheric refractive index structure constant) is one of the most important physical quantities characterizing turbulence effects. Its precise measurement is crucial for applications such as optical wave atmospheric transmission, satellite-to-ground laser communications, target tracking and identification, and other optoelectronic engineering applications. Common detection methods include temperature pulsation and optical remote sensing. The former calculates the atmospheric turbulence profile based on the measurement of atmospheric temperature disturbances. Successive developments include microthermal sensors, sonic velocity meters, and sounding balloons. These techniques are indirect and subject to certain errors. The most typical and currently most commonly used method is differential image motion radar (DIM radar). This method first focuses a laser on a specific location in space to form a laser guide star. Using a dual-aperture telescope and a high-performance array detector (ICCD / EMCCD), the center-of-mass jitter of the laser image at that location is measured to calculate the atmospheric coherence length at that location. By sequentially varying the position of the laser guide star, the atmospheric turbulence intensity profile can be further inverted. However, due to the need to change the position of the laser guide star in sequence, the time and spatial resolution of DIM radar measurements are low. In addition, there are problems such as low quantum efficiency of ICCD / EMCCD in weak light detection, no response in some special bands (such as near-infrared and mid-infrared), and inability to image. There is also the bottleneck problem of foreign technology embargo.

[0003] Prior art patent application CN1945355A discloses an atmospheric turbulence detection lidar using a position-sensitive detector. This lidar employs a pulsed laser as its transmitting light source. Rayleigh scattered echoes received by a dual-aperture telescope are focused by a reflecting prism onto the position-sensitive detectors on either side. The position coordinate signals are converted to digital signals by an A / D converter and processed by a microprocessor to obtain a profile of the atmospheric coherence length and refractive index structure constant. However, this patent uses a four-quadrant detector to detect the centroid of the light spot, requiring signals from all four quadrants for detection, resulting in poor detection capabilities. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a device for realizing high-precision and high-resolution detection of atmospheric turbulence intensity profiles by using a single-pixel detector without imaging function instead of an array detector.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] An atmospheric turbulence high-resolution profile detection laser radar system device includes: a pulse laser 100, a double-aperture telescope 200 and a subsequent optical calculation centroid detection unit 345;

[0007] The pulse laser 100 emits a pulsed laser beam into the atmosphere; atmospheric turbulence at different positions on the laser path disturbs the amplitude and phase of the light wave, and the backscattered light spot carrying the disturbance information reaches the binocular telescope 200 at the receiving end; the dual apertures of the binocular telescope 200 form images, and each image point is modulated according to a fixed pattern by the light intensity modulator in the subsequent light calculation centroid detection unit 345. The subsequent light calculation centroid detection unit 345 then correlates the detected light intensity value with the modulation signal to obtain the centroid distribution of the light spot at different path positions, accumulates a certain number of laser pulses, calculates the jitter variance of the light spot centroid at the corresponding position, and obtains the atmospheric turbulence distribution profile information on the path passed by the laser.

[0008] Technical effect: The pulsed laser beam emitted by the pulsed laser is emitted into the atmosphere, and the backscattered echo signal carrying atmospheric turbulence information is received by a binocular telescope 200 with two sub-apertures. The subsequent light calculation centroid detection unit 345 uses a modulator with a fixed modulation mode to modulate the light intensity distribution of the echo signal, so as to obtain the zero-order moment and two first-order moments of the echo spot, and calculate the jitter variance of the spot centroid at the corresponding height, further realizing high-precision, high-temporal and high-space resolution detection research of the atmospheric coherence length and refractive index structure constant profile.

[0009] In one embodiment of the present invention, the subsequent optical calculation centroid detection unit 345 includes a first centroid detection unit 300 and a second centroid detection unit 400 having the same components and working principles; and further includes a data acquisition system 510;

[0010] The first centroid detection unit 300 is located on the first sub-aperture imaging path in the binocular telescope 200, and the second centroid detection unit 400 is located on the second sub-aperture imaging path in the binocular telescope 200;

[0011] The light intensity values ​​and modulation signals detected by the first centroid detection unit 300 and the second centroid detection unit 400 are both collected by the data collection system 510 .

[0012] In one embodiment of the present invention, the first centroid detection unit 300 includes a first reflector 311, a first APD detector 312; a second reflector 321, a first modulator 322, a second APD detector 323; a second modulator 331 and a third APD detector 332;

[0013] The first sub-aperture imaging light path is split by the first reflector 311, the reflected light is received by the first APD detector 312, and the transmitted light propagates along a straight line to the second reflector 321 for further splitting.

[0014] The reflected light from the second reflecting mirror 321 is modulated by the first modulator 322 and then received by the second APD detector 323 . The transmitted light from the second reflecting mirror 321 is modulated by the second modulator 331 and then received by the third APD detector 332 .

[0015] In one embodiment of the present invention, the first centroid detection unit 300 includes a first converging lens 313, a second converging lens 324, and a third converging lens 333;

[0016] The first converging lens 313 is located between the first reflecting mirror 311 and the first APD detector 312. The reflected light from the first reflecting mirror 311 is converged by the first converging lens 313 and then received by the first APD detector 312.

[0017] The second converging lens 324 is located between the first modulator 322 and the second APD detector 323. The light modulated by the first modulator 322 is converged by the second converging lens 324 and then received by the second APD detector 323.

[0018] The third converging lens 333 is located between the second modulator 331 and the third APD detector 332 . The light modulated by the second modulator 331 is converged by the third converging lens 333 and then received by the third APD detector 332 .

[0019] In one embodiment of the present invention, the modulation mode f1(x, y) pre-set by the first modulator 322 is that the light intensity gradually changes along the horizontal X-axis direction; the modulation mode f2(x, y) pre-set by the second modulator 331 is that the light intensity gradually changes along the vertical Y-axis direction; wherein (x, y) is the coordinate of the light intensity value.

[0020] In one embodiment of the present invention, the coordinates of the centroid of the light spot in the first centroid detection unit 300 are obtained by the following formula:

[0021]

[0022] In the formula, (x c1 ,y c1 ) is the coordinate of the center of mass of the light spot in the first center of mass detection unit, I1(x, y) is the light intensity value at the coordinate (x, y) on the first sub-aperture imaging path, f3(x, y) is a matrix with a value of 1, and m is the total number of x(y).

[0023] In one embodiment of the present invention, the method for obtaining the coordinates of the center of mass of the light spot in the second center of mass detection unit 400 reuses the formula for obtaining the coordinates of the center of mass of the light spot in the first center of mass detection unit 300, and the formula parameters are correspondingly substituted into the light intensity value at the coordinate (x, y) on the second sub-aperture imaging path. The modulation mode of the third modulator 422 in the second center of mass detection unit 400 is that the light intensity gradually changes along the horizontal X-axis direction, and the modulation mode of the fourth modulator 431 is that the light intensity gradually changes along the longitudinal Y-axis direction.

[0024] In one embodiment of the present invention, the entrance pupil of the binocular telescope 200 includes a first sub-aperture 211 and a second sub-aperture 221; the diameter D of each sub-aperture satisfies d>2D; wherein the aperture spacing d between the first sub-aperture 211 and the second sub-aperture 221.

[0025] In one embodiment of the present invention, a first wedge 212 and a second wedge 222 are disposed within the entrance pupil. The first wedge 212 is located on the path of the image formed by the first sub-aperture 211, and the second wedge 222 is located on the path of the image formed by the second sub-aperture 221. By adjusting the angles of the first wedge 212 and the second wedge 222, the images of the first sub-aperture 211 and the second sub-aperture 221 at the focal plane positions are separated by a predetermined distance.

[0026] Compared to existing technologies, the present invention offers the following advantages: Compared to differential image motion radar, the system uses collimated pulsed laser beams, enabling a single laser pulse to obtain centroid information for different path locations. Continuously emitting a certain number of laser pulses enables profile detection of the atmospheric coherence length and refractive index structure constant, resulting in higher temporal and spatial resolution. Compared to position-sensitive detector lidar, the present invention utilizes the principle of correlated imaging, overcoming the former's requirement for all four quadrant detectors to generate signals for detection, thereby significantly improving detection capabilities.

[0027] This invention combines lidar and correlation imaging technologies, utilizing an APD detector without imaging capabilities to detect intensity. This overcomes the foreign technology embargo on high-performance image detectors, which suffer from low quantum efficiency or even no response in certain wavelengths (such as the near-infrared and mid-infrared). This technology holds significant scientific significance for high-resolution and high-precision detection of atmospheric turbulence profiles, improving the efficiency of adaptive optics correction, and applying optoelectronic engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of an atmospheric turbulence high-resolution profile detection lidar system device according to an embodiment of the present invention.

[0029] Figure 2 Schematic diagram of a modulation mode of a modulator according to an embodiment of the present invention.

[0030] Figure 3Schematic diagram of another modulation mode of the modulator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described with reference to the accompanying drawings.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0033] See also Figure 1 As shown, this embodiment provides a high-resolution atmospheric turbulence profile detection lidar system, comprising a pulsed laser 100, a binocular telescope 200, and a subsequent light centroid calculation detection unit 345. The pulsed laser 100 emits a pulsed laser beam into the atmosphere. Atmospheric turbulence at different locations along the laser path perturbs the amplitude and phase of the light wave, and backscattered light spots carrying this perturbation information reach the receiving binocular telescope 200. Images are formed through the dual apertures of the binocular telescope 200. Each image point is modulated according to a fixed pattern by a light intensity modulator in the subsequent light centroid calculation detection unit 345. The subsequent light centroid calculation detection unit 345 then correlates the detected light intensity values ​​with the modulation signal to obtain the distribution of the light spot centroids at different path locations. A certain number of laser pulses are emitted cumulatively, and the jitter variance of the light spot centroids at the corresponding locations is calculated to obtain the atmospheric turbulence distribution profile information along the laser path.

[0034] In one embodiment of the present invention, the wavelength of the pulsed laser 100 is 1064 nm, the pulse width is 8 ns, the repetition frequency is 100 Hz, the pulse repetition frequency f, and the cumulative number of pulses N determine the time resolution Δt = N / f for measuring the atmospheric turbulence profile. Assuming N = 2000-3000, then Δt is 20-30 s, which meets Taylor's "turbulence freezing" hypothesis time.

[0035] In this embodiment, a beam expander 110 is further provided on the pulse laser optical path of the pulse laser 100. The beam expander 110 has a beam expansion ratio of 5-10 times and is used to expand the emitted pulse laser beam by 5-10 times while compressing the emission angle of the laser beam to 1 / 10 to 1 / 5 of the original, in order to achieve near-parallel laser light emission, increase energy density, and improve detection distance.

[0036] In one embodiment of the present invention, the entrance pupil of binocular telescope 200 includes a first sub-aperture 211 and a second sub-aperture 221. The diameter D of each sub-aperture satisfies d>2D. The spacing d between the first sub-aperture 211 and the second sub-aperture 221 satisfies the Taylor freezing hypothesis of turbulence. Furthermore, a first wedge 212 and a second wedge 222 are positioned within the entrance pupil. The first wedge 212 is located on the path of the image formed by the first sub-aperture 211, and the second wedge 222 is located on the path of the image formed by the second sub-aperture 221. By adjusting the angles of the first wedge 212 and the second wedge 222, the images of the first sub-aperture 211 and the second sub-aperture 221 at the focal plane are separated by a certain distance.

[0037] In this embodiment, it is clear that the optical path passing through the first sub-aperture 211 and the first wedge 212 is the first sub-aperture imaging path, and the optical path passing through the second sub-aperture 221 and the second wedge 222 is the second sub-aperture imaging path.

[0038] See also Figures 1 to 3 As shown, in one embodiment of the present invention, the subsequent optical calculation centroid detection unit 345 includes a first centroid detection unit 300 and a second centroid detection unit 400 with the same component devices and working principles, as well as a data acquisition system 510 and a terminal device 520.

[0039] The first centroid detection unit 300 is located on the first sub-aperture imaging path, and the second centroid detection unit 400 is located on the second sub-aperture imaging path. The light intensity values ​​and modulation signals detected by the first centroid detection unit 300 and the second centroid detection unit 400 are collected by the data acquisition system 510 and output to the terminal device 520 for storage and calculation.

[0040] In this embodiment, the first centroid detection unit 300 includes three light spot branches, namely a first light spot branch, a second light spot branch and a third light spot branch.

[0041] The first light spot branch is provided with a first reflecting mirror 311 , a first APD detector 312 and a first converging lens 313 .

[0042] The second light spot branch is provided with a second reflecting mirror 321 , a first modulator 322 , a second APD detector 323 and a second converging lens 324 .

[0043] The third light spot branch is provided with a second modulator 331 , a third APD detector 332 and a third converging lens 333 .

[0044] In this embodiment, the first converging lens 313 is located between the first reflector 311 and the first APD detector 312. The light path of the first sub-aperture imaging path passes through the first reflector 311 for splitting, the reflected light is converged by the first converging lens 313 and received by the first APD detector 312, and the transmitted light propagates along a straight line to the second reflector 321 for further splitting.

[0045] In this embodiment, the second converging lens 324 is located between the first modulator 322 and the second APD detector 323 . The reflected light from the second reflector 321 is modulated by the first modulator 322 , converged by the second converging lens 324 , and then received by the second APD detector 323 .

[0046] In this embodiment, the third converging lens 333 is located between the second modulator 331 and the third APD detector 332 . The transmitted light passing through the second reflector 321 is modulated by the second modulator 331 , converged by the third converging lens 333 , and then received by the third APD detector 332 .

[0047] In one embodiment of the present invention, it is clear that the second centroid detection unit 400 correspondingly includes three light spot branches, namely a fourth light spot branch, a fifth light spot branch and a sixth light spot branch.

[0048] In this embodiment, a third reflector 411 , a fourth APD detector 412 and a fourth converging lens 413 are provided on the fourth light spot branch.

[0049] The fourth converging lens 413 is located between the third reflector 411 and the fourth APD detector 412. The light path of the second sub-aperture imaging path is split by the third reflector 411. The reflected light is converged by the fourth converging lens 413 and received by the fourth APD detector 412. The transmitted light propagates along a straight line to the fourth reflector 421 and is split again.

[0050] In this embodiment, the fifth light spot branch is provided with a fourth reflector 421, a third modulator 422, a fifth APD detector 423, and a fifth converging lens 424. The fifth converging lens 424 is located between the third modulator 422 and the fifth APD detector 423. The light reflected by the fourth reflector 421 is modulated by the third modulator 422, converged by the fifth converging lens 424, and then received by the fifth APD detector 423.

[0051] In this embodiment, the sixth light spot branch is provided with a fourth modulator 431, a sixth APD detector 432, and a sixth converging lens 433. The sixth converging lens 433 is located between the fourth modulator 431 and the sixth APD detector 432. The transmitted light passing through the fourth reflector 421 is modulated by the fourth modulator 431, converged by the sixth converging lens 433, and then received by the sixth APD detector 432.

[0052] In one embodiment of the present invention, the reflection and transmission ratio of the first reflector 311 and the third reflector 411 is 1:4, and the reflection and transmission ratio of the second reflector 321 and the fourth reflector 421 is 1:1. This configuration is to make the energy of the transmitted light greater than that of the reflected light.

[0053] In one embodiment of the present invention, the light intensity signals detected by the first APD detector 312, the second APD detector 323, the third APD detector 332, the fourth APD detector 412, the fifth APD detector 423, and the sixth APD detector 432 are collected by the data acquisition system 510 and output to the terminal device 520 for storage and calculation. The pulsed laser 100 and the terminal device 520 are in communication connection, and the timing of the pulsed laser and the acquisition card is controlled by the terminal device 520. That is, after the pulsed laser 100 emits laser light, after a certain delay, the data acquisition system 510 is triggered to start acquisition.

[0054] In this embodiment, the six APD detectors are all avalanche diode detectors, the data acquisition system 510 is a six-channel high-speed transient recorder with a sampling frequency of 20 MHz, and the spatial resolution of the corresponding atmospheric coherence length and atmospheric turbulence intensity profile results is 7.5 m, and the terminal device 520 is a computer.

[0055] In one embodiment of the present invention, the first modulator 322 and the third modulator 422 are pre-set to a specific modulation mode f1(x,y) in which the light intensity gradually changes along the horizontal X-axis direction. Figure 2 The modulation mode f2(x,y) preset by the second modulator 331 and the fourth modulator 431 is that the light intensity gradually changes along the longitudinal Y-axis direction, where (x,y) is the coordinate of the light intensity value, see Figure 3 shown.

[0056] In one embodiment of the present invention, three special modulation matrices are constructed: f1(x, y) = x for the first modulator 322 and the third modulator 422, and f2(x, y) = y for the second modulator 331 and the fourth modulator 431. Furthermore, since no modulator is provided on the first and fourth light spot branches, the modulation matrices corresponding to these two light spot branches are f3(x, y) = 1. Taking the coordinates of the light spot centroid in the first centroid detection unit 300 as an example, the coordinates are obtained using the following formula:

[0057]

[0058] In the formula, (x c1 ,y c1 ) is the coordinate of the center of mass of the light spot in the first center of mass detection unit, I1(x,y) is the light intensity value at the coordinate (x,y) on the first sub-aperture imaging path, f3(x,y) is a matrix with a value of 1, and m is the total number of coordinates x(y).

[0059] There is no doubt that the method for obtaining the coordinates of the center of mass of the light spot in the second center of mass detection unit 400 reuses the formula for obtaining the coordinates of the center of mass of the light spot in the first center of mass detection unit 300, and the formula parameters correspond to the light intensity value at the coordinate (x, y) on the second sub-aperture imaging path, and the modulation matrix corresponding to the modulation mode of the third modulator 422 and the fourth modulator 431.

[0060] In this embodiment, the measurement of atmospheric turbulence intensity requires cumulative calculation of the centroid drift of multiple echo spots at the same height z to obtain their jitter variance. and atmospheric coherence length r0 and atmospheric coherence length r0 and refractive index structure constant The contour relationship is calculated as follows:

[0061]

[0062] Where, is the jitter variance of the line connecting the centroids of the two apertures of the binocular telescope, λ is the laser wavelength, k = 2π / λ is the wave number, D and d are the diameter of each subaperture of the binocular telescope and the spacing between the two apertures, respectively. z is the position on the laser path, which can be understood as the calculated coordinates of the centroid of the light spot in the first centroid detection unit 300 or the coordinates of the centroid of the light spot in the second centroid detection unit 400.

[0063] In this embodiment, compared with the knowledge of single-pixel imaging (correlated imaging), it can be seen that for the optical path of the first sub-aperture imaging path, the ratio of the light intensity value of the second APD detector 323 to the light intensity value of the first APD detector 312 corresponds to the centroid coordinates of the optical path in the X direction, and the ratio of the light intensity value of the third APD detector 332 to the light intensity value of the first APD detector 312 corresponds to the centroid coordinates of the optical path in the Y direction. Similarly, for the optical path of the second sub-aperture imaging path, the ratio of the light intensity value of the fifth APD detector 423 to the light intensity value of the fourth APD detector 412 corresponds to the centroid coordinates of the optical path in the X direction, and the ratio of the light intensity value of the sixth APD detector 432 to the light intensity value of the fourth APD detector 412 corresponds to the centroid coordinates of the optical path in the Y direction. Therefore, after each echo signal is split, its intensity is modulated using modulators in the form of f1(x,y), f2(x,y), and f3(x,y). The APD detector without area array imaging function can be used to detect the centroid of the light spot. This is the principle of fast positioning of the scintillation spot by measuring light calculation, and the jitter variance is further calculated. The atmospheric turbulence intensity profile distribution is obtained by inverting the formula for obtaining the jitter variance. It is important to note that due to the use of simple geometric moment modulation, there is no need to expand single-pixel imaging to multiple pixels (e.g., 64 pixels, 128 pixels, etc.). This eliminates the traditional single-pixel imaging problem of sacrificing temporal resolution in exchange for spatial information, thus enabling real-time and rapid location of the scintillation spot.

[0064] See also Figures 1 to 3 As shown, in another embodiment of the present invention, a detection method of an atmospheric turbulence high-resolution profile detection laser radar system is provided, which uses the above-mentioned atmospheric turbulence high-resolution profile detection laser radar system device, including:

[0065] The 1064nm pulse laser 100 is powered on and preheated for about half an hour to stabilize its light output energy. The light beam is expanded and nearly collimated by the beam expander 110 and emitted into the atmosphere. Atmospheric turbulence at different positions along the path disturbs the amplitude and phase of the light wave. The backscattered light spot carrying the disturbance information reaches the binocular telescope 200 at the receiving end, and is simultaneously imaged by the first sub-aperture 211 and the second sub-aperture 221 of the binocular telescope 200 and enters the subsequent light calculation centroid detection unit 345.

[0066] After passing through the first sub-aperture 211, each image point passes through the first light spot branch, the second light spot branch, and the third light spot branch, and is modulated by the modulators on the first to third light spot branches according to a preset pattern. After passing through the APD detectors on the first to third light spot branches, it is collected by the data acquisition system 510 and transmitted to the terminal device 520. The terminal device 520 uses the light intensity values ​​detected by the APD detectors on the first to third light spot branches and the modulation signals of the modulators to obtain the distribution of the light spot centroids at different path positions, accumulates a certain number of laser pulses, and calculates the jitter variance of the light spot centroids at the path position.

[0067] Similarly, each image point after passing through the second sub-aperture 221 passes through the fourth light spot branch, the fifth light spot branch, and the sixth light spot branch, and is modulated according to a preset pattern by the modulators on the fourth to sixth light spot branches. After passing through the APD detectors on the fourth to sixth light spot branches, it is collected by the data acquisition system 510 and transmitted to the terminal device 520. The terminal device 520 uses the light intensity values ​​detected by the APD detectors on the fourth to sixth light spot branches and the modulation signals of the modulators to obtain the distribution of the light spot centroids at different path positions, accumulates a certain number of laser pulses, and calculates the jitter variance of the light spot centroids at the path position.

[0068] The present invention obtains the jitter variance of the centroid of the light spot at two different path positions, and its function replaces the high-performance array detector in the traditional imaging radar. Finally, the profile of the atmospheric coherence length and the refractive index structure constant on the path passed by the laser is obtained by calculation.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0070] The above-mentioned embodiments merely represent the implementation methods of the invention. The protection scope of the present invention is not limited to the above-mentioned embodiments. For those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention, which all fall within the protection scope of the present invention.

Claims

1. A high-resolution atmospheric turbulence profile detection laser radar system device, characterized in that: include: A pulsed laser (100), a binocular telescope (200), and a subsequent optical calculation center of mass detection unit (345); A pulse laser (100) emits a pulse laser beam into the atmosphere; atmospheric turbulence at different positions on the laser path disturbs the amplitude and phase of the light wave, and backscattered light spots carrying disturbance information reach a binocular telescope (200) at a receiving end; images are formed by the dual apertures of the binocular telescope (200), and each image point is modulated according to a fixed pattern by a light intensity modulator in a subsequent light calculation centroid detection unit (345). The subsequent light calculation centroid detection unit (345) performs a correlation operation on the detected light intensity value and the modulation signal to obtain the centroid distribution of light spots at different path positions, cumulatively emits a certain number of laser pulses, calculates the jitter variance of the light spot centroid at the corresponding position, and obtains the atmospheric turbulence distribution profile information on the path passed by the laser.

2. The atmospheric turbulence high-resolution profile detection laser radar system device according to claim 1, characterized in that: The subsequent optical calculation centroid detection unit (345) includes a first centroid detection unit (300) and a second centroid detection unit (400) having the same component devices and working principles; and also includes a data acquisition system (510); The first centroid detection unit (300) is located on a first sub-aperture imaging path in the binocular telescope (200), and the second centroid detection unit (400) is located on a second sub-aperture imaging path in the binocular telescope (200); The light intensity values ​​and modulation signals detected by the first centroid detection unit (300) and the second centroid detection unit (400) are both collected by the data collection system (510).

3. The atmospheric turbulence high-resolution profile detection laser radar system according to claim 2, characterized in that: The first centroid detection unit (300) includes a first reflector (311), a first APD detector (312); a second reflector (321), a first modulator (322), a second APD detector (323); a second modulator (331) and a third APD detector (332); The light path of the first sub-aperture imaging path is split by the first reflector (311), the reflected light is received by the first APD detector (312), and the transmitted light propagates along a straight line to the second reflector (321) and is split again; The reflected light from the second reflector (321) is modulated by the first modulator (322) and received by the second APD detector (323), and the transmitted light from the second reflector (321) is modulated by the second modulator (331) and received by the third APD detector (332).

4. The atmospheric turbulence high-resolution profile detection laser radar system device according to claim 3, characterized in that: The first centroid detection unit (300) includes a first converging lens (313), a second converging lens (324), and a third converging lens (333); The first converging lens (313) is located between the first reflecting mirror (311) and the first APD detector (312); the reflected light of the first reflecting mirror (311) is converged by the first converging lens (313) and then received by the first APD detector (312); The second converging lens (324) is located between the first modulator (322) and the second APD detector (323); the light modulated by the first modulator (322) is converged by the second converging lens (324) and then received by the second APD detector (323); The third converging lens (333) is located between the second modulator (331) and the third APD detector (332). Light modulated by the second modulator (331) is converged by the third converging lens (333) and then received by the third APD detector (332).

5. The atmospheric turbulence high-resolution profile detection laser radar system device according to claim 3, characterized in that: The modulation pattern f1(x,y) preset by the first modulator (322) is that the light intensity gradually changes along the transverse X-axis direction; The modulation pattern f2(x, y) preset by the second modulator (331) is that the light intensity gradually changes along the longitudinal Y-axis direction; wherein (x, y) is the coordinate of the light intensity value.

6. The atmospheric turbulence high-resolution profile detection laser radar system device according to claim 5, characterized in that: The coordinates of the center of mass of the light spot in the first center of mass detection unit (300) are obtained by the following formula: In the formula, (x c1 ,y c1 ) is the coordinate of the center of mass of the light spot in the first center of mass detection unit, I1(x,y) is the light intensity value at the coordinate (x,y) on the first sub-aperture imaging path, f3(x,y) is a matrix with a value of 1, and m is the total number of coordinates x(y).

7. The atmospheric turbulence high-resolution profile detection laser radar system according to claim 6, characterized in that: The coordinates of the center of mass of the light spot in the second center of mass detection unit (400) are obtained by reusing the formula for obtaining the coordinates of the center of mass of the light spot in the first center of mass detection unit (300), and the parameters of the formula are correspondingly substituted into the light intensity value at the coordinate (x, y) on the second sub-aperture imaging path. The modulation mode of the third modulator (422) in the second center of mass detection unit (400) is that the light intensity gradually changes along the transverse X-axis direction, and the modulation mode of the fourth modulator (431) is that the light intensity gradually changes along the longitudinal Y-axis direction.

8. The atmospheric turbulence high-resolution profile detection laser radar system according to claim 1, characterized in that: The entrance pupil of the binocular telescope (200) comprises a first sub-aperture (211) and a second sub-aperture (221); the diameter D of each sub-aperture satisfies d>2D; wherein the aperture spacing d between the first sub-aperture (211) and the second sub-aperture (221) is.

9. The atmospheric turbulence high-resolution profile detection laser radar system according to claim 8, characterized in that: A first wedge (212) and a second wedge (222) are provided in the entrance pupil; the first wedge (212) is located on a path through which the first sub-aperture (211) forms an image, and the second wedge (222) is located on a path through which the second sub-aperture (221) forms an image; and by adjusting the angles of the first wedge (212) and the second wedge (222), the images of the first sub-aperture (211) and the second sub-aperture (221) at the focal plane position are separated by a certain distance.

10. A detection method for an atmospheric turbulence high-resolution profile detection laser radar system, characterized in that: The atmospheric turbulence high-resolution profile detection lidar system device according to any one of claims 1 to 9 comprises: A pulse laser (100) emits a pulse laser beam into the atmosphere; atmospheric turbulence at different positions on the laser path disturbs the amplitude and phase of the light wave, and backscattered light spots carrying disturbance information reach a binocular telescope (200) at a receiving end; images are formed by the dual apertures of the binocular telescope (200), and each image point is modulated according to a fixed pattern by a light intensity modulator in a subsequent light calculation centroid detection unit (345). The subsequent light calculation centroid detection unit (345) performs a correlation operation on the detected light intensity value and the modulation signal to obtain the centroid distribution of light spots at different path positions, cumulatively emits a certain number of laser pulses, calculates the jitter variance of the light spot centroid at the corresponding position, and obtains the atmospheric turbulence distribution profile information on the path passed by the laser.

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