A wind-measuring laser radar optical antenna signal-to-noise ratio cooperative optimization method and system

Abstract

The application discloses a wind measurement laser radar optical antenna signal-to-noise ratio cooperative optimization method and system, relates to the technical field of laser radar, and first obtains an axial farthest detection distance boundary through spatial geometry solution from scanning system parameters, and then determines a full-range equalization focusing center located in the middle section of the range according to a symmetric attenuation law of a coherent detection axial efficiency; a two-dimensional optimization space is constructed with a light aperture radius and an image side beam waist focusing position as optimization variables, a full-range carrier-to-noise ratio average value of received light power and received link noise of atmospheric backscattering is taken into account as a target for traversal optimization, an optimal light aperture radius and an optimal focusing position are obtained, then an effective focal length and a dynamic cutoff ratio are cooperatively solved, and accordingly, aberration correction and assembly finalization are completed; the application improves and flattens full-range sensitivity under the same aperture constraint, suppresses near-end signal collapse, does not need to additionally add field lenses, pinholes and other light control elements, and is beneficial to the miniaturization of the optical antenna.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, specifically to a method and system for coordinating the signal-to-noise ratio optimization of optical antennas in wind-measuring lidar. Background Technology

[0002] When designing telescope systems for coherent Doppler wind lidar, the focal length of the telescope is generally fixed at infinity (i.e., emitting parallel light). There is a lack of methods for selecting and analyzing the focal length of ground-based tilt-scanning wind lidar within a limited detection range. During system design, aperture optimization is mainly aimed at maximizing the carrier-to-noise ratio at a certain fixed far-field detection distance. In order to compensate for signal collapse at a specific far distance, a larger physical aperture is usually required. However, when detecting at close range (such as within a few hundred meters), due to the lack of full-range equalization considerations, the signal at both ends of the edge is prone to collapse. This leads to the need to rely on complex field lens physical defocusing, pinhole apertures, or mechanical light control mechanisms such as secondary mirror shading in subsequent hardware to barely improve the near-field blind zone. This makes the entire telescope system complex and bulky, unable to meet the miniaturization requirements of lidar.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for coordinating the signal-to-noise ratio of optical antennas for wind-measuring lidar, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for co-optimizing the signal-to-noise ratio of an optical antenna for wind-measuring lidar, comprising the following steps:

[0007] S1. Obtain the scanning system parameters and fiber optic hardware parameters of the ground-based inclined scanning system wind-measuring lidar, and determine the axial maximum detection distance boundary of the monocular telescope optical axis direction through spatial geometric calculation based on the scanning system parameters.

[0008] S2. According to the distribution law of symmetrical attenuation of coherent detection axial efficiency relative to the focusing position, determine the full-range balanced focusing center constraint position within the range defined by the boundary of the farthest axial detection distance.

[0009] S3. Construct a two-dimensional optimization space with the telescope aperture radius and the image-side beam waist focusing position as two optimization variables, and define the full-range detection interval with the focusing center constraint position.

[0010] S4. Calculate the average full-range carrier-to-noise ratio node by node in the two-dimensional optimization space. The average full-range carrier-to-noise ratio takes into account the atmospheric backscattered received optical power, antenna heterodyne efficiency and receiver link noise at each detection distance. Select the node with the largest average full-range carrier-to-noise ratio to obtain the optimal aperture radius and the optimal image-side beam waist focusing position.

[0011] S5. Calculate the effective focal length from the optimal image-side beam waist focusing position and the fiber hardware parameters, and match it to obtain the dynamic cutoff ratio corresponding to the optimal aperture radius. Output the two as first-order optical parameters.

[0012] S6. Using the first-order optical parameters as fixed constraints, complete the aberration correction and assembly of the optical antenna.

[0013] Furthermore, the scanning system parameters include the target vertical wind measurement height, the half-angle of the monocular telescope horizontal plane, and the half-angle of the monocular telescope vertical plane. The angle of the monocular telescope central axis is obtained by combining the two half-angles according to the cosine relationship. Then, the boundary of the farthest axial detection distance is calculated based on the geometric mapping relationship between the target vertical wind measurement height and the angle of the central axis.

[0014] Furthermore, according to the Cauchy-Lorentz distribution model characterizing the axial detection efficiency distribution of coherent radar, the focusing center constraint position is taken at half the boundary of the farthest axial detection distance, so that the axial efficiency attenuation of the focusing center constraint position is symmetrical towards the near end and the far end.

[0015] Furthermore, in the two-dimensional optimization space, the light-transmitting aperture radius is discretely divided within the upper limit of the miniaturized size according to a preset radius step value, and the image-side beam waist focusing position is discretely divided between zero and the boundary of the farthest axial detection distance according to a preset distance step value. The discrete nodes of the two dimensions are combined in pairs to form optimization nodes.

[0016] Furthermore, the antenna heterodyne efficiency is obtained based on the backpropagation local oscillator theory, through the Gaussian series expansion of the complex amplitude distribution of the signal light and the local oscillator light in the receiving aperture plane and the overlap integral within the aperture boundary; the carrier-to-noise ratio at each detection distance is the product of the atmospheric backscattered received light power at that distance and the antenna heterodyne efficiency, relative to the ratio of the sum of the equivalent noise power of the detector shot noise, the receiving circuit thermal noise and the laser relative intensity noise, and the average value of the carrier-to-noise ratio at all discrete detection distances in the full-range detection interval is taken as the full-range carrier-to-noise ratio mean.

[0017] Furthermore, the Rayleigh length of the Gaussian beam is determined by the fiber optic hardware parameters, and an equation about the effective focal length is established and solved based on the imaging law of the Gaussian beam thin lens. The dynamic cutoff ratio is the ratio of the optimal aperture diameter to the diameter of the incident Gaussian spot at the entrance pupil of the telescope. When calculating the average carrier-to-noise ratio across the entire range, an aperture size constraint weighting factor can also be introduced to achieve a balance between detection performance and overall system size.

[0018] Furthermore, the first-order optical parameters are imported into the optical design software and locked as non-adjustable boundaries. Aberration correction of multiple lenses is carried out to output lens processing parameters. The theoretical object distance is inverted from the optimal image-side beam waist focusing position and effective focal length through the Gaussian beam imaging relationship to complete the physical assembly and shaping. During assembly, a servo focusing mechanism driven by a stepper motor or piezoelectric ceramic can be used for closed-loop fine adjustment based on the theoretical object distance.

[0019] This invention also discloses a signal-to-noise ratio (SNR) collaborative optimization system for wind-measuring lidar optical antennas, used to execute the above-mentioned wind-measuring lidar optical antenna SNR collaborative optimization method, comprising:

[0020] The parameter acquisition module is used to acquire scanning system parameters and fiber optic hardware parameters;

[0021] The geometric boundary calculation module is used to calculate the axial maximum detection distance boundary of the monocular telescope in the direction of the optical axis based on the scanning system parameters.

[0022] The focusing center constraint module is used to determine the full-range balanced focusing center constraint position according to the distribution law of symmetrical attenuation of coherent detection axial efficiency.

[0023] The carrier-to-noise ratio optimization module is used to construct a two-dimensional optimization space with the aperture radius and the image-side beam waist focusing position as optimization variables. It calculates the average carrier-to-noise ratio across the entire range, taking into account atmospheric backscattered received optical power and received link noise, node by node, and outputs the optimal aperture radius and the optimal image-side beam waist focusing position.

[0024] The first-order parameter collaborative solution module is used to solve the effective focal length and match the dynamic cutoff ratio, and output the first-order optical parameters;

[0025] The assembly and shaping module is used to output lens design constraints and fiber optic assembly position parameters based on the first-order optical parameters.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention calculates the maximum axial detection distance boundary based on scanning system parameters, and positions the focusing center clamp in the middle of the range according to the symmetrical attenuation law of axial efficiency. Within the two-dimensional optimization space formed by the aperture radius and the image-side beam waist focusing position, it optimizes the average carrier-to-noise ratio (CNR) across the entire range, taking into account the received optical power and the noise of the receiving link, and outputs two first-order optical parameters: effective focal length and dynamic cutoff ratio. Under the same aperture constraint, it improves the average CNR across the entire range, suppresses near-end signal-to-noise ratio attenuation, and flattens the sensitivity distribution across the entire range. It eliminates the need for additional field lenses, pinhole apertures, and other light control components, compresses the size of the optical antenna, and adapts to the miniaturization requirements of lidar. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall method flow of the present invention;

[0029] Figure 2 This is a schematic diagram of the three-dimensional spatial geometry calculation of the lidar of the present invention;

[0030] Figure 3 This is a schematic diagram of the system module framework of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0032] Example:

[0033] Please see Figures 1 to 3 This embodiment presents a complete implementation process of a method for co-optimizing the signal-to-noise ratio of an optical antenna for wind-measuring lidar:

[0034] A method for co-optimizing the signal-to-noise ratio of an optical antenna for wind-measuring lidar, comprising the following steps:

[0035] S1. Obtain radar scanning system parameters and calculate the maximum axial detection range boundary of the monocular telescope through geometric calculation;

[0036] Reference Figure 2 This describes the spatial geometric relationship between the telescope optical axis, scanning angle, and detection space of a ground-based tilt-scanning wind-measuring lidar, used to solve for the boundary of the farthest axial detection distance. This is the half-angle of the monocular telescope in the horizontal plane, used to reflect the range of the telescope's half-scan angle in the horizontal plane. This is the half-angle of the monocular telescope's vertical plane, used to reflect the range of the telescope's half-scan angle within the vertical plane. The angle between the telescope's central axis and the target's vertical wind height is H. As the boundary of the farthest detection distance along the axis, LOS1-LOS4 represent the detection lines of four independent telescopes.

[0037] In general design, spaceborne radar defaults to setting the detection range to infinity, lacking accurate axial distance calculation under ground-based inclined scanning systems. This results in a lack of accurate boundary constraints in optical parameter design. Therefore, this invention first locks in the hard boundary of axial detection, providing clear range limitations: First, it collects three types of parameters preset by the radar system: the target vertical wind measurement height, the half-angle of the monocular telescope in the horizontal plane, and the half-angle of the monocular telescope in the vertical plane. These three parameters together determine the spatial scanning cone range of the ground-based radar, thus reflecting the slant range boundary corresponding to the vertical wind measurement height that the radar actually needs to cover. The central axis angle of the monocular telescope is solved through spatial geometric relationships. For a two-dimensional scanning telescope structure, the scanning angle in the horizontal plane and the scanning angle in the vertical plane together synthesize the actual deflection angle of the telescope's optical axis. The two satisfy the synthesis relationship of the cosine product. The formula for calculating the central axis angle is: ,in, The angle between the central axes of the monocular telescope, This is the half-angle of the monocular telescope's horizontal plane, used to reflect the radar's scanning angle range within the horizontal plane. The angle is the half-angle of the vertical plane of the monocular telescope, used to reflect the scanning angle range of the radar in the vertical plane. It is the resultant of the two spatial direction angles. The projections of the horizontal plane deflection angle and the vertical plane deflection angle onto the optical axis together constitute the cosine value of the total deflection angle. Based on the geometric relationship between the vertical wind measurement height and the slant range, the boundary of the farthest axial detection distance is derived: ,in, H represents the maximum detection range boundary along the axial direction, reflecting the maximum detection range that needs to be covered in the direction of the telescope's optical axis. H represents the target's vertical wind measurement height, reflecting the upper limit of the vertical wind measurement height that the radar needs to reach.

[0038] Targeted geometric calculations are performed on the ground-based inclined scanning system to obtain more accurate finite-distance boundaries, providing accurate boundary inputs for subsequent miniaturized parameter design and avoiding far-field parameter design deviations.

[0039] S2. Based on the boundary of the farthest axial detection distance, determine the constraint position of the focusing center for full-range balance;

[0040] By clamping the focusing center in the middle of the range, the spatial distribution of optical field energy is achieved, which improves the near-far signal-to-noise ratio even with a small aperture. This avoids the existing method of setting the focusing center at the farthest detection distance, preventing severe near-field signal collapse, and eliminating the need for additional mechanical light control mechanisms to compensate for near-field blind spots.

[0041] The Cauchy-Lorentz spatial distribution model is used to characterize the axial detection efficiency distribution of the coherent radar. The axial detection efficiency of the coherent wind lidar shows a symmetric attenuation trend as the distance deviates from the focusing center, which conforms to the distribution characteristics of the Lorentz function. The efficiency is the highest at the focusing center and gradually decreases towards both sides. The constraint position of the focusing center is set to a half position of the axial maximum detection distance boundary, that is: , where is the constraint position of the focusing center, which is used to reflect the spatial position of the highest point of axial detection efficiency. Using the symmetry of the Lorentz distribution, the highest efficiency point is placed at the midpoint of the range, so that the efficiency attenuation at the near end and the far end is symmetric, and the balanced distribution of the signal-to-noise ratio over the full range is realized. The focusing center is moved to the middle section of the range through the pre-algorithm clamping, so that the full-range sensitivity curve can be flattened from the source without adding additional hardware mechanisms such as field lenses and diaphragms, eliminating the detection blind zones at the near and far ends, and reducing the structural complexity at the same time, thereby facilitating the miniaturization of the optical antenna.

[0042] S3. Obtain the hardware parameters of the radar optical fiber, and construct a two-dimensional optimization matrix space of the clear aperture radius and the focusing position of the image-space beam waist;

[0043] Construct a two-dimensional matrix space, and take both the clear aperture and the focusing position as optimization variables: first, read the inherent hardware parameters of the optical fiber matched with the radar system, including the numerical aperture of the optical fiber, the mode field radius of the output end of the optical fiber, and the laser spot M 2 factor. The three types of parameters are determined by the inherent hardware attributes of the optical fiber and the laser. A two-dimensional optimization matrix space is constructed. The first dimension is the clear aperture radius, the traversal range is set according to the upper size limit of the miniaturization design, and is discretely divided according to the preset radius step value. The second dimension is the focusing position of the image-space beam waist, the traversal range covers the interval from zero to the axial maximum detection distance boundary, and is discretely divided according to the preset distance step value. The discrete nodes of the two dimensions are combined in pairs to form all calculation nodes of the two-dimensional matrix.

[0044] S4. Calculate the mean value of the full-range carrier-to-noise ratio node by node in the two-dimensional optimization matrix space, and obtain the optimal clear aperture radius and the optimal image-space beam waist focusing position;

[0045] By performing a full matrix traversal optimization, the optimal aperture and focusing position adapted to the current hardware are dynamically solved, maximizing the full-range carrier-to-noise ratio under small-aperture constraints. An antenna heterodyne efficiency evaluation function is constructed based on the backpropagation local oscillator theory. The receiver's local oscillator light is equivalent to a Gaussian beam propagating backward along the optical axis to the detection area, while the atmospheric backscattered signal light propagates forward along the optical axis to the receiving aperture. The two beams coherently overlap within the receiving aperture plane. The heterodyne efficiency is determined by the integral of the optical field overlap between the two beams within the aperture range. The complex amplitude distribution of the signal light and the local oscillator light within the receiving aperture plane is characterized using a Gaussian function. The overlap integral under finite aperture boundaries is solved by Gaussian series expansion, yielding an analytical formula for calculating the antenna heterodyne efficiency, thus forming an antenna heterodyne efficiency evaluation function containing Gaussian series expansion terms. The evaluation function takes as input parameters the aperture radius, the image-side beam waist focusing position, and fiber hardware parameters. The fiber hardware parameters include the fiber numerical aperture, the output mode field radius, and the laser spot M² factor, which are used to determine the initial divergence angle and mode field size of the incident Gaussian beam. Combined with the image-side beam waist focusing position, the spot radius and wavefront curvature at the receiving aperture plane can be calculated. The aperture radius is used to determine the spatial integration boundary of the overlap integral. The output of the evaluation function is the antenna heterodyne efficiency under the corresponding parameter configuration, with a value ranging from 0 to 1, which characterizes the energy coupling efficiency between the signal light and the local oscillator light during coherent aliasing. The calculation interval for the full-range average carrier-to-noise ratio (CNR) is from the preset near-end detection boundary to the axial farthest detection distance boundary. Within this interval, several discrete detection distance points are selected according to a preset distance step size. The transmission distance corresponding to each discrete detection distance point is substituted into the antenna heterodyne efficiency evaluation function to calculate the antenna heterodyne efficiency value for each distance point. Then, for each discrete detection distance point, the CNR is calculated by combining the atmospheric backscattered received optical power at the corresponding distance, the heterodyne efficiency at that point, and the receiver link noise level. The average CNR value of all discrete points is taken to obtain the full-range average CNR corresponding to the current parameter node. The noise level is an inherent parameter of radar reception, including detector shot noise, receiver circuit thermal noise, and laser relative intensity noise, which is determined by the hardware properties of the detector and front-end circuit.

[0046] The carrier-to-noise ratio at a single detection distance point The formula used is:

[0047]

[0048] The received optical power corresponding to atmospheric backscattering at a distance R is determined by the laser emission power, atmospheric transmittance, backscattering coefficient, and telescope receiving area. , , These represent the detector shot noise power, the receiver circuit thermal noise power, and the equivalent noise power corresponding to the laser relative intensity noise, respectively. Let R be the antenna heterodyne efficiency at the detection distance R.

[0049] For all nodes within the two-dimensional matrix, the average carrier-to-noise ratio (CNR) across the entire range is calculated by substituting preset step values ​​for the aperture radius and the image-side beam waist focusing position. After traversing all nodes, the average CNR of all nodes is numerically compared, and the node with the largest average CNR is selected. The aperture radius corresponding to this node is determined as the optimal aperture radius, and the corresponding image-side beam waist focusing position is determined as the optimal image-side beam waist focusing position. Using the average CNR across the entire range as the optimization target, the atmospheric backscattered received optical power and the noise parameters of the receiving system at different detection distances are introduced into the calculation process. The signal range attenuation effect and system noise are incorporated into the performance evaluation to obtain the optimal optical parameters adapted to the actual working conditions of the radar system.

[0050] The traversal optimization process can introduce an aperture size constraint weight factor, incorporating the aperture size into the optimization objective function. The larger the weight factor value, the more the optimization result will favor a smaller aperture size. The value of the weight factor is set according to the overall size index requirements. By adjusting the weight, a balance can be achieved between detection performance and size, enabling the highest heterodyne efficiency to be obtained under extremely small aperture, supporting the miniaturization design of optical antennas.

[0051] S5. Based on the optimal aperture radius and optimal focusing position, the effective focal length and dynamic cutoff ratio are obtained, and the first-order optical parameters are output.

[0052] Existing technologies lack precise methods for calculating focal length over finite distances, and typically assume the focal length to be infinite. This invention is based on the Gaussian beam imaging principle, calculates the effective focal length according to the optimal focusing position, and obtains the dynamic cutoff ratio, thereby outputting the first-order parameters as a hard constraint for optical design.

[0053] First, the Rayleigh length of the Gaussian beam is calculated based on the fiber optic hardware parameters. The Rayleigh length reflects the collimation distance of the Gaussian beam and is determined by the initial mode field radius and the laser wavelength. Based on the thin lens imaging law of the Gaussian beam, a quadratic equation in univariate form regarding the effective focal length f is constructed: Where f is the effective focal length of the telescope. Rayleigh length of a Gaussian beam, used to reflect the collimation and transmission characteristics of a Gaussian beam. The image-side beam waist is the focusing position, i.e., the optimal focusing position. The above equation is derived from the transmission formula of a Gaussian beam through a thin lens, reflecting the constraint relationship between the object-side beam waist position, the image-side beam waist position, and the lens focal length.

[0054] After obtaining the optimal aperture radius, the diameter of the Gaussian spot at the entrance pupil of the telescope is calculated, and the ratio of the aperture diameter to the incident spot diameter is used as the dynamic cutoff ratio.

[0055] The output first-order optical parameters include effective focal length, aperture, and dynamic cutoff ratio, which directly determine the overall size and basic performance. The effective focal length is obtained for finite detection distance, replacing the approximate assumption of infinite focal length, improving heterodyne efficiency under small aperture, and adaptively adjusting with the optimal aperture radius and optimal focusing position, which is more suitable for miniaturization performance requirements than fixed constants.

[0056] S6. Based on the first-order optical parameters, complete the aberration correction and assembly of the optical antenna.

[0057] First, the first-order optical parameters are imported into the optical design software as fixed constraints. The effective focal length and aperture are set as non-adjustable hard boundaries. Under these constraints, the structural design and aberration correction of multiple lenses are carried out. Finally, the lens processing parameters that meet the image quality requirements are output to avoid subsequent design deviations from the volume target.

[0058] Then, based on the optimal focusing position and effective focal length, the theoretical object distance of the telescope is obtained by inversion using the Gaussian beam imaging formula, thus completing the physical assembly and finalization of the optical antenna.

[0059] Specifically, the mechanical focusing mechanism during assembly can be replaced with an automatic servo mechanism driven by a stepper motor or piezoelectric ceramic, which can achieve closed-loop fine adjustment based on the calculated object distance parameters, thereby further improving assembly accuracy.

[0060] Reference Figure 3 The present invention also discloses a signal-to-noise ratio (SNR) collaborative optimization system for a wind-measuring lidar optical antenna, used to execute a method for collaborative optimization of the SNR of a wind-measuring lidar optical antenna, comprising:

[0061] The parameter acquisition module is used to acquire scanning system parameters and fiber optic hardware parameters;

[0062] The geometric boundary calculation module is used to calculate the axial maximum detection distance boundary of the monocular telescope in the direction of the optical axis based on the scanning system parameters.

[0063] The focusing center constraint module is used to determine the full-range balanced focusing center constraint position according to the distribution law of symmetrical attenuation of coherent detection axial efficiency.

[0064] The carrier-to-noise ratio optimization module is used to construct a two-dimensional optimization space with the aperture radius and the image-side beam waist focusing position as optimization variables. It calculates the average carrier-to-noise ratio across the entire range, taking into account atmospheric backscattered received optical power and received link noise, node by node, and outputs the optimal aperture radius and the optimal image-side beam waist focusing position.

[0065] The first-order parameter collaborative solution module is used to solve the effective focal length and match the dynamic cutoff ratio, and output the first-order optical parameters;

[0066] The assembly and shaping module is used to output lens design constraints and fiber optic assembly position parameters based on the first-order optical parameters.

[0067] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0068] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0069] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

[0070] The scope of protection of this application covers equivalent substitutions and conventional improvements made by those skilled in the art based on the technical concept of this invention, and is not limited to the specific embodiments described above.

Claims

1. A method for co-optimizing the signal-to-noise ratio of an optical antenna for wind-measuring lidar, characterized in that, The specific steps include: S1. Obtain the scanning system parameters and fiber optic hardware parameters of the ground-based inclined scanning system wind-measuring lidar, and determine the axial maximum detection distance boundary of the monocular telescope optical axis direction through spatial geometric calculation based on the scanning system parameters. S2. According to the distribution law of symmetrical attenuation of coherent detection axial efficiency relative to the focusing position, determine the full-range balanced focusing center constraint position within the range defined by the boundary of the farthest axial detection distance. S3. Construct a two-dimensional optimization space with the telescope aperture radius and the image-side beam waist focusing position as two optimization variables, and define the full-range detection interval with the focusing center constraint position. S4. Calculate the average full-range carrier-to-noise ratio node by node in the two-dimensional optimization space. The average full-range carrier-to-noise ratio takes into account the atmospheric backscattered received optical power, antenna heterodyne efficiency and receiver link noise at each detection distance. Select the node with the largest average full-range carrier-to-noise ratio to obtain the optimal aperture radius and the optimal image-side beam waist focusing position. S5. Calculate the effective focal length from the optimal image-side beam waist focusing position and the fiber hardware parameters, and match it to obtain the dynamic cutoff ratio corresponding to the optimal aperture radius. Output the two as first-order optical parameters. S6. Using the first-order optical parameters as fixed constraints, complete the aberration correction and assembly of the optical antenna.

2. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: The scanning system parameters include the target vertical wind measurement height, the horizontal half-angle of the monocular telescope, and the vertical half-angle of the monocular telescope. The central axis angle of the monocular telescope is obtained by combining the horizontal half-angle and the vertical half-angle using a cosine relationship. Then, the axial maximum detection distance boundary is calculated based on the geometric mapping relationship between the target vertical wind measurement height and the central axis angle.

3. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: The axial detection efficiency distribution of coherent radar is characterized by the Cauchy-Lorentz distribution model. The focus center constraint position is taken at half the position of the boundary of the farthest axial detection distance, so that the axial efficiency attenuation of the focus center constraint position is symmetrical towards the near end and the far end.

4. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: The antenna heterodyne efficiency is obtained based on the backpropagation local oscillator theory. The local oscillator light at the receiving end is equivalent to a Gaussian beam propagating in the opposite direction along the optical axis. The complex amplitude distribution of the signal light and the local oscillator light in the receiving aperture plane is expanded into a Gaussian series, and the overlap integral is obtained within the boundary of the light-transmitting aperture. The carrier-to-noise ratio at each detection distance is the product of the atmospheric backscattered received light power and the antenna heterodyne efficiency at that distance, and the ratio of the sum of the equivalent noise power of the detector shot noise, the receiving circuit thermal noise and the laser relative intensity noise.

5. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: The Rayleigh length of the Gaussian beam is determined by the fiber optic hardware parameters. An equation about the effective focal length is established and solved based on the imaging law of the Gaussian beam thin lens. The dynamic cutoff ratio is the ratio of the aperture diameter corresponding to the optimal aperture radius to the diameter of the incident Gaussian spot at the entrance pupil of the telescope.

6. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: In the two-dimensional optimization space, the light aperture radius is discretely divided within the upper limit of the miniaturized size according to a preset radius step value, and the image-side beam waist focusing position is discretely divided between zero and the boundary of the farthest detection distance in the axial direction according to a preset distance step value. The discrete nodes of the two dimensions are combined in pairs to form optimization nodes.

7. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: When calculating the average carrier-to-noise ratio across the entire range, an aperture size constraint weighting factor is introduced. The value of the aperture size constraint weighting factor is set based on the overall volume index, and the larger the value, the more the optimization result is biased towards a smaller light-transmitting aperture.

8. The method for coordinated optimization of signal-to-noise ratio of optical antenna for wind-measuring lidar according to claim 1, characterized in that: The first-order optical parameters are imported into the optical design software and locked as non-adjustable boundaries. Aberration correction of multiple lenses is carried out to output lens processing parameters. The theoretical object distance is inverted from the relationship between the optimal image-side beam waist focusing position and the effective focal length through Gaussian beam imaging, and the physical assembly and finalization of the optical antenna are completed.

9. A system for collaborative optimization of signal-to-noise ratio (SNR) of a wind-measuring lidar optical antenna, used to execute the method for collaborative optimization of SNR of a wind-measuring lidar optical antenna according to any one of claims 1-8, characterized in that, include: The parameter acquisition module is used to acquire scanning system parameters and fiber optic hardware parameters; The geometric boundary calculation module is used to calculate the axial maximum detection distance boundary of the monocular telescope in the optical axis direction based on the scanning system parameters. The focusing center constraint module is used to determine the full-range balanced focusing center constraint position according to the distribution law of symmetrical attenuation of coherent detection axial efficiency. The carrier-to-noise ratio optimization module is used to construct a two-dimensional optimization space with the aperture radius and the image-side beam waist focusing position as optimization variables. It calculates the average carrier-to-noise ratio across the entire range, taking into account atmospheric backscattered received optical power and received link noise, node by node, and outputs the optimal aperture radius and the optimal image-side beam waist focusing position. The first-order parameter collaborative solution module is used to solve the effective focal length and match the dynamic cutoff ratio, and output the first-order optical parameters; The assembly and shaping module is used to output lens design constraints and fiber optic assembly position parameters based on the first-order optical parameters.

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