A low-altitude meteorological multi-parameter lidar

Abstract

The present invention relates to the technical field of measuring low-altitude meteorological parameters using laser radar, and discloses a low-altitude meteorological multi-parameter laser radar, which controls two light sources, namely an infrared light source and an ultraviolet light source, through a data processing and control system, and performs laser emission in a certain time sequence; the scattered light generated by the two light sources interacting with the atmosphere is received by a composite optical antenna, and finally displayed by a display terminal after being processed by the data processing and control system. The present invention, through the designed optical composite optical antenna system, does not affect the conventional receiving cross-sectional area, and through a specific spectroscopic process, structural form, and specific size design, the conventional shielding secondary mirror is utilized, thereby not only improving the use efficiency, but also realizing the simultaneous observation of multiple meteorological parameters. The whole machine is small in size, and is easy to deploy in low-altitude use scenarios such as urban rooftops, so as to realize rapid and accurate observation of low-altitude meteorological parameters and ensure the flight safety of low-altitude aircraft.

Description

Technical Field

[0001] The invention relates to the technical field of measuring low-altitude meteorological parameters by using laser radar, and in particular to a low-altitude meteorological multi-parameter laser radar. Background Art

[0002] "Low-altitude economy" refers to economic activities that rely on low-altitude airspace and are dominated by the general aviation industry. It involves industries and application scenarios such as low-altitude flight, aviation tourism, scientific research and education. Products include drones, helicopters, etc. Under the new economic format, the development and use of low-altitude meteorological measurement equipment is very urgent. The overall system of the front boundary layer temperature profile detection equipment is large, occupies a large area, has weak maneuverability, and in order to suppress background light, only a small field of view can be used for reception. The measurement of wind speed and direction adopts the coherent Doppler principle. The radar needs to realize the synthesis of wind speed, and multiple beams must be used, generally 4 to 8 beams, with observation angles ranging from 20-30°. At the same time, the detection systems of wind speed and direction and temperature and humidity cannot be integrated together, and joint observation cannot be achieved.

[0003] The present invention solves the problem that the current laser radar wind measurement system and the temperature and humidity measurement radar are quite different and cannot be integrated together to achieve joint observation. It further solves the problem that the temperature and humidity radar and the wind measurement laser radar are deployed simultaneously, which occupies a large area and has low mobility. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a low-altitude meteorological multi-parameter laser radar, which solves the problem that the current laser radar wind measurement system and the temperature and humidity measurement radar are quite different and cannot be integrated together to achieve joint observation. It further solves the problem that the temperature and humidity radar and the wind measurement laser radar are deployed simultaneously, which occupies a large area and has low mobility.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A low-altitude meteorological multi-parameter laser radar, comprising: a servo system, an infrared light source, a composite optical antenna, an ultraviolet light source, an environmental control system, a micron spectrometer unit, a nanometer spectrometer unit, a transient acquisition and recording system, a data processing and control system, and a display terminal;

[0007] The composite optical antenna includes a reflective system and a transmissive system, wherein the reflective system is used to receive ultraviolet signals, and the transmissive system is used to transmit and receive infrared rays from an infrared light source;

[0008] The data processing and control system controls the infrared light source and the ultraviolet light source to emit light, the ultraviolet light source is directly emitted into the atmosphere through the emission component, and the infrared light source is emitted through the optical fiber, the micron spectrometer unit and then the composite optical antenna;

[0009] The micron spectrometer separates the ultraviolet light and infrared light received by the composite optical antenna, and the ultraviolet light is then decomposed into different channels by the nanometer spectrometer. After the signals of each channel are converted into electrical signals, they are collected and stored by the transient acquisition and recording system, and transmitted to the data processing and control system. After data processing by the data processing and control system, they are displayed through the display terminal;

[0010] The servo system is used to switch the light emission angle of the composite optical antenna;

[0011] The data processing and control system controls the environmental control system while collecting and controlling the data, and controls the temperature and humidity of the system.

[0012] Preferably, the composite optical antenna comprises a wedge-shaped mirror, a wedge-shaped mirror seat, an ultraviolet primary mirror, an ultraviolet primary mirror seat, an adapter plate, an extinction tube, a three-leaf support, and a shielding secondary mirror; the micron spectroscopic unit comprises a micron color separation plate, an aperture, a second collecting lens, a converging lens, and a first collecting lens; the transmission system comprises a first collecting lens, a micron color separation plate, an extinction tube, a shielding secondary mirror, and a wedge-shaped mirror; the infrared light source passes through the first collecting lens, further passes through the micron color separation plate via the extinction tube, and is then transmitted to the shielding secondary mirror at a certain divergence angle; the infrared light source is further transmitted to the wedge-shaped mirror through the shielding secondary mirror, and is output to the atmosphere at a certain inclination angle by the wedge-shaped mirror; the infrared light source interacts with the atmosphere to generate a backscattered light signal; the light signal enters the first collecting lens again via the wedge-shaped mirror, the shielding secondary mirror, and the micron spectroscopic color separation plate, and further enters the detection unit through the optical fiber; the detection unit receives the corresponding light signal and converts it into an electrical The sub-signal is transmitted to the transient acquisition and recording system; the reflective system includes an ultraviolet primary mirror, an ultraviolet primary mirror seat, an extinction tube, a shielding secondary mirror, an aperture, a collecting lens 2, and a converging lens. The ultraviolet light source is controlled by the data processing and control system. After receiving the corresponding instruction, the ultraviolet light source is emitted to the atmosphere through the transmitting component, and the ultraviolet laser interacts with the atmosphere to generate multi-path backscattered light signals. The multi-path optical signals can pass through the ultraviolet primary mirror and the shielding secondary mirror in turn and enter the micron spectrometer unit. The micron spectrometer unit transmits the optical signal into the collecting lens 2. The collecting lens 2 transmits the optical signal to the nano spectrometer unit through an optical fiber. The nano spectrometer unit separates the optical signal into 6 channel signals, and connects the optical signals of the 6 channels to the detection unit respectively. The optical signal is converted into an electrical signal through the detection unit, and the electrical signal is further transmitted to the transient acquisition and recording system.

[0013] Preferably, the infrared light source differs from the ultraviolet light source by more than 1 micron.

[0014] Preferably, the shielding secondary mirror is composed of two surfaces, and the two surfaces of the ultraviolet primary mirror and the shielding secondary mirror satisfy the following geometric relationship:

[0015] ,

[0016] Among them, the distance between the UV primary mirror and the shielding secondary mirror is d, and the focal extension is , the center thickness of the obstructed secondary mirror is t, the refractive index of the obstructed secondary mirror material is n, and the radius of curvature of the lower surface of the obstructed secondary mirror is , the curvature radius of the upper surface of the shielded secondary mirror is .

[0017] Preferably, the system shielding ratio of the reflective system is less than 1 / 4, the ultraviolet primary mirror is processed by a dielectric film process, and the reflectivity in a specific ultraviolet band is greater than 99.5%; a dichroic film is additionally coated under the shielding secondary mirror, and the reflectivity in a specific ultraviolet band is greater than 99%, and the transmittance in a specific infrared band is greater than 99%; an infrared anti-reflection film is coated on the shielding secondary mirror, and the transmittance in a specific infrared band is greater than 99%; the surface accuracy of the wedge-shaped mirror, the shielding secondary mirror, and the reflecting primary mirror are all better than λ / 8.

[0018] Preferably, the infrared light source is transmitted to the micron spectrometer unit via optical fiber; the ultraviolet light source is directly emitted into the atmosphere via a transmitting component; the micron spectrometer unit and the nano spectrometer unit both reflect the infrared band and transmit the ultraviolet band, with the reflectivity and transmittance both being greater than 99%; both types of spectrometer units use optical fiber output, and the nano spectrometer unit further separates the ultraviolet band signal into 6 channels, with each two channels inverting a profile.

[0019] Preferably, the collecting lens 1 is equipped with a focusing ring, which can be focused forward and backward; the micron color separation plate adopts a high-stable fixing mechanism, which is adjustable in two dimensions; the three-leaf support is a double-layer structure, including a servo fixing frame and a shielding secondary mirror fixing frame, the shielding secondary mirror is firmly connected to the shielding secondary mirror fixing frame, the servo system includes a driving motor and a gear pair, the driving motor is fixedly arranged on the servo fixing frame, and the wedge mirror is firmly connected to the wedge mirror seat; the fastening connection is made through the side, which does not affect the transmission area of ​​the wedge mirror; the driving motor drives the wedge mirror seat to rotate through the gear pair.

[0020] Preferably, the diameter of the ultraviolet primary mirror is greater than 300 mm, the focal length is greater than or equal to 2 m, and the outer diameter d of the servo system is less than 100 mm.

[0021] The present invention has the following beneficial effects:

[0022] (1) The low-altitude meteorological multi-parameter lidar has a compact structure and multiple parameters share one optical system, which reduces the size and weight of the product and makes the equipment deployment more convenient. It is conducive to adapting low-altitude flight equipment to quickly conduct low-altitude atmospheric detection and is easy to deploy in low-altitude usage scenarios such as urban rooftops, realizing rapid and accurate observation of low-altitude meteorological parameters and ensuring the flight safety of low-altitude aircraft.

[0023] (2) The low-altitude meteorological multi-parameter laser radar can realize a single optical-mechanical structure and receive two optical signals through a designed composite optical antenna, thus realizing the combination of a transmission system and a reflection system, saving material costs and improving space utilization. The use of a composite optical system enables the acquisition, storage, data processing and control unit to share a single system, saving system resources and reducing equipment costs.

[0024] (3) This low-altitude meteorological multi-parameter lidar can achieve synchronous measurement of temperature, humidity, aerosols, wind speed and wind direction in the boundary layer through a set of systems, integrating temperature and humidity radar with wind lidar for joint observation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the system of the present invention;

[0026] Figure 2 It is a structural composition diagram of the present invention;

[0027] Figure 3 It is a structural diagram of the composite optical antenna of the present invention;

[0028] Figure 4 is a schematic diagram of the shielding ratio of the optical receiving antenna in the present invention;

[0029] Figure 5 A diagram showing the composition of the composite optical antenna of the present invention;

[0030] Figure 6 for Figure 5 A schematic diagram of the enlarged structure of the middle A area:

[0031] Figure 7 It is a schematic diagram of specific geometric relationships in the present invention;

[0032] Figure 8 This is a structural diagram of the three-leaf support.

[0033] In the figure: 1. servo system; 2. infrared light source; 3. composite optical antenna; 301. wedge mirror; 302. wedge mirror mount; 302. gear pair; 304. drive motor; 305. ultraviolet primary mirror; 306. ultraviolet primary mirror mount; 307. adapter plate; 308. extinction tube; 309. three-leaf support; 3091. servo fixing frame; 3092. shielding secondary mirror fixing frame; 310. shielding secondary mirror; 4. ultraviolet light source; 5. environmental control system; 6. micron spectrometer unit; 601. micron color separation plate; 602. aperture; 603. collecting lens 2; 604. converging lens; 605. collecting lens 1; 7. nanometer spectrometer unit; 8. transient acquisition and recording system; 9. data processing and control system; 10. display terminal; 12. composite optical antenna sealing plate; 13. antenna frame. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 The present invention provides a technical solution: a low-altitude meteorological multi-parameter laser radar, comprising: a servo system 1, an infrared light source 2, a composite optical antenna 3, an ultraviolet light source 4, an environmental control system 5, a micron spectrometer unit 6, a nanometer spectrometer unit 7, a transient acquisition and recording system 8, a data processing and control system 9, and a display terminal 10;

[0036] The composite optical antenna 3 includes a reflective system and a transmissive system, wherein the reflective system is used to receive ultraviolet signals, and the transmissive system is used to transmit and receive infrared rays from the infrared light source 2;

[0037] The data processing and control system 9 controls the infrared light source 2 and the ultraviolet light source 4 to emit light. The ultraviolet light source 4 is directly emitted into the atmosphere through the emission component, and the infrared light source 2 is emitted through the optical fiber, the micron spectroscopic unit 6 and then the composite optical antenna 3;

[0038] The micron spectrometer unit 6 separates the ultraviolet light and infrared light received by the composite optical antenna 3, and the ultraviolet light is then decomposed into different channels by the nanometer spectrometer unit 7. After the signals of each channel are converted into electrical signals, they are collected and stored by the transient acquisition and recording system 8, and transmitted to the data processing and control system 9. After data processing by the data processing and control system 9, they are displayed through the display terminal 10;

[0039] The servo system 1 is used to switch the light emission angle of the composite optical antenna 3;

[0040] The data processing and control system 9 controls the environmental control system 5 while collecting and controlling the data, and controls the temperature and humidity of the system.

[0041] The present invention controls two light sources, namely, the infrared light source 2 and the ultraviolet light source 4, to emit lasers in a certain sequence at the same time through the data processing and control system 9; after the laser is emitted, the data processing and control system 9 controls the servo system 1 to switch the angle of the composite optical antenna 3; the laser hits the atmosphere, reacts with the atmosphere, and returns multiple backscattered light, which is received by the composite optical antenna 3, and then separated from the ultraviolet light by the micron spectrometer 6, and the ultraviolet light is decomposed into different channels by the nanometer spectrometer 7. After the optical signals of each channel are converted into electrical signals, they are collected and stored by the transient acquisition and recording system 8, and transmitted to the data processing and control system 9. Finally, after being processed by the data processing and control system 9, they are displayed by the display terminal 10. The overall structure of the device proposed in the present invention is compact. Through the arrangement of the composite optical antenna 3, the transmission system and the reflection system are combined. Two optical signals can be received through one optical-mechanical structure. Multiple parameters share one optical system, which saves material costs, improves space utilization, reduces product size and weight, and makes equipment deployment more convenient. The use of the composite optical system enables the collection, storage, data processing and control units to share a set of systems. One set of systems realizes the synchronous measurement of temperature, humidity, aerosol, wind speed and wind direction in the boundary layer, saves system resources and reduces equipment costs.

[0042] In this embodiment, the composite optical antenna 3 includes a wedge mirror 301, a wedge mirror seat 302, an ultraviolet primary mirror 305, an ultraviolet primary mirror seat 306, an adapter plate 307, an extinction tube 308, a three-leaf support 309, and a shielding secondary mirror 310. The micron spectroscopic unit 6 includes a micron color separation sheet 601, an aperture 602, a collection lens 2 603, a convergence lens 604, and a collection lens 1 605. The transmission system includes a collection lens 1 605, a micron color separation sheet 601, an extinction tube 308, a shielding secondary mirror 310, and a wedge mirror. 301, the infrared light source 2 passes through the collecting lens 605, further passes through the micron color separation plate 601 and passes through the extinction tube 308 to be transmitted to the shielding secondary mirror 310 at a certain divergence angle, and the infrared light source 2 is transmitted to the wedge mirror 301 through the shielding secondary mirror 310, and is output to the atmosphere by the wedge mirror 301 at a certain inclination angle. The infrared light source 2 interacts with the atmosphere to generate a backscattered light signal, which enters the atmosphere again through the wedge mirror 301, the shielding secondary mirror 310, and the micron color separation plate. To the collecting lens 1 605, and further enter the detection unit through the optical fiber. The detection unit receives the corresponding optical signal and converts it into an electronic signal and transmits it to the transient collection and recording system 8; the reflective system includes an ultraviolet primary mirror 305, an ultraviolet primary mirror seat 306, an extinction tube 308, a shielding secondary mirror 310, an aperture 602, a collecting lens 2 603, and a converging lens 604. The ultraviolet light source 4 is controlled by the data processing and control system 9. After receiving the corresponding instruction, the ultraviolet light source 4 is emitted to the atmosphere through the emitting component. The ultraviolet laser is emitted into the atmosphere and reacts with the atmosphere to return multiple backscattered light signals. The multiple optical signals can pass through the ultraviolet primary mirror 305 and the shielding secondary mirror 310 in turn and enter the micron spectrometer unit 6. The micron spectrometer unit 6 transmits the optical signal into the collecting lens 2 603. The collecting lens 2 603 transmits the optical signal to the nano spectrometer unit 7 through the optical fiber. The nano spectrometer unit 7 separates the optical signal into 6 channel signals, and connects the optical signals of the 6 channels to the detection unit respectively, and transmits them to the transient collection and recording system 8 through the detection unit.

[0043] In this embodiment, the infrared light source 2 and the ultraviolet light source 4 differ by more than 1 micron.

[0044] For the ultraviolet reflective system, the Cassegrain telescope system is composed of the ultraviolet primary mirror 305 and the lower surface of the shielding secondary mirror 310. Given the aperture D of the ultraviolet primary mirror 305, the relative aperture F of the ultraviolet reflective system (the ratio of the aperture D of the ultraviolet primary mirror 305 to the focal length f of the system); the relative aperture F1 of the ultraviolet primary mirror 305 (the ratio of the aperture D of the ultraviolet primary mirror 305 to the focal length f of the ultraviolet primary mirror 305) The curvature radius of the UV primary mirror 305 is r1, the focus of the UV primary mirror 305 is the first focus, the distance from the vertex of the lower surface of the shielded secondary mirror 310 to the first focus is the object distance l2 of the shielded secondary mirror 310, and the distance from the vertex of the lower surface of the shielded secondary mirror 310 to the focus of the UV reflective system is the image distance of the shielded secondary mirror 310. The radius of curvature of the lower surface of the secondary mirror 310 is r2, and the focal length is ; For a given focal extension , then:

[0045] ,

[0046] ,

[0047] ,

[0048] And block the secondary mirror magnification:

[0049] ,

[0050] Then we get: ,

[0051] ,

[0052] At this time, the distance d between the UV primary mirror and the shielding secondary mirror is:

[0053] ,

[0054] The central thickness of the shielding secondary mirror 310 is t, the refractive index of the shielding secondary mirror material is n, the radius of curvature of the upper surface of the shielding secondary mirror is r3, and the focal length of the shielding secondary mirror 310 is , the focal position of the shielding secondary mirror 310 coincides with the focal position of the ultraviolet reflective system;

[0055] ,

[0056] The focal length of a thick lens is calculated using the formula:

[0057] ,

[0058] The curvature radius r3 of the upper surface of the shielding secondary mirror 310 can be obtained.

[0059] Reference Figure 6 As shown, in this embodiment, the shielding secondary mirror 310 is composed of two surfaces, and the two surfaces of the ultraviolet primary mirror 305 and the shielding secondary mirror 310 satisfy the following geometric relationship:

[0060] ,

[0061] Among them, the distance between the UV primary mirror and the shielding secondary mirror is d, and the focal extension is , the center thickness of the obstructed secondary mirror is t, the refractive index of the obstructed secondary mirror material is n, and the radius of curvature of the lower surface of the obstructed secondary mirror is , the curvature radius of the upper surface of the shielded secondary mirror is .

[0062] In this embodiment, the system shielding ratio of the reflective system is less than 1 / 4, the ultraviolet primary mirror 305 is processed by a dielectric film process, and the reflectivity in a specific ultraviolet band is greater than 99.5%; a dichroic film is additionally coated on the bottom of the shielding secondary mirror 310, and the reflectivity in a specific ultraviolet band is greater than 99%, and the transmittance in a specific infrared band is greater than 99%; an infrared anti-reflection film is coated on the top of the shielding secondary mirror 310, and the transmittance in a specific infrared band is greater than 99%; the surface accuracy of the wedge-shaped mirror 301, the shielding secondary mirror 310, and the reflecting primary mirror are all better than λ / 8.

[0063] In this embodiment, the infrared light source 2 is transmitted to the micron spectrometer unit 6 through optical fiber; the ultraviolet light source 4 is directly emitted into the atmosphere through the transmitting component, and the micron spectrometer unit 6 and the nano spectrometer unit 7 both reflect the infrared band and transmit the ultraviolet band, and the reflectivity and transmittance are both greater than 99%; both types of spectrometer units use optical fiber output, and the nano spectrometer unit 7 further separates the ultraviolet band signal into 6 channels, and inverts a profile for every two channels.

[0064] Reference Figure 5 As shown, in this embodiment, the collecting lens 605 is equipped with a focusing ring, which can be focused forward and backward; the micron color separation plate 601 adopts a high-stability fixing mechanism, which can be adjusted in two dimensions; the three-leaf support 309 is a double-layer structure, including a servo fixing frame 3091 and a shielding secondary mirror fixing frame 3092, and the shielding secondary mirror 310 is firmly connected to the shielding secondary mirror fixing frame 3092. The servo system 1 includes a driving motor 304 and a gear pair 302. The driving motor 304 is fixedly set on the servo fixing frame 3091, and the wedge mirror 301 is firmly connected to the wedge mirror seat 302; the fastening connection is made through the side, which does not affect the transmission area of ​​the wedge mirror 301; the driving motor 304 drives the wedge mirror seat 302 to rotate through the gear pair 302. There are two three-leaf support members 309 arranged above and below, which are used to install the wedge-shaped mirror seat 302 and the ultraviolet primary mirror 305 respectively. The ultraviolet primary mirror 305 and the three-leaf support members 309 are connected by a frame. The three-leaf support members 309 are all processed with low-stress high-strength materials and subjected to stress relief treatment. The three-leaf support members 309 are made of invar materials.

[0065] Reference Figure 4As shown, in this embodiment, the diameter of the ultraviolet primary mirror 305 is greater than 300 mm, the focal length is greater than or equal to 2 m, and the outer diameter d of the servo system 1 is less than 100 mm. The outer diameter d of the servo system 1 and the ultraviolet primary mirror 305D determine the shielding ratio of the ultraviolet system. The smaller the shielding ratio, the larger the receiving area of ​​the ultraviolet receiving antenna and the smaller the receiving area of ​​the transmission receiving antenna.

[0066] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-altitude meteorological multi-parameter laser radar, characterized in that: include: Servo system, infrared light source, composite optical antenna, ultraviolet light source, environmental control system, micron spectrometer unit, nanometer spectrometer unit, transient acquisition and recording system, data processing and control system, display terminal; The composite optical antenna includes a reflective system and a transmissive system, wherein the reflective system is used to receive ultraviolet signals, and the transmissive system is used to transmit and receive infrared rays from an infrared light source; The data processing and control system controls the infrared light source and the ultraviolet light source to emit light, the ultraviolet light source is directly emitted into the atmosphere through the emission component, and the infrared light source is emitted through the optical fiber, the micron spectrometer unit and then the composite optical antenna; The micron spectrometer separates the ultraviolet light and infrared light received by the composite optical antenna, and the ultraviolet light is then decomposed into different channels by the nanometer spectrometer. After the signals of each channel are converted into electrical signals, they are collected and stored by the transient acquisition and recording system, and transmitted to the data processing and control system. After data processing by the data processing and control system, they are displayed through the display terminal; The servo system is used to switch the light emission angle of the composite optical antenna; The data processing and control system controls the environmental control system while collecting and controlling the data, and controls the temperature and humidity of the system.

2. The low-altitude meteorological multi-parameter laser radar according to claim 1, characterized in that: The composite optical antenna includes a wedge mirror, a wedge mirror seat, an ultraviolet primary mirror, an ultraviolet primary mirror seat, an adapter plate, an extinction tube, a three-leaf support, and a shielding secondary mirror. The micron spectroscopic unit includes a micron color separation plate, an aperture, a second collecting lens, a converging lens, and a first collecting lens. The transmission system includes a first collecting lens, a micron color separation plate, an extinction tube, a shielding secondary mirror, and a wedge mirror. The infrared light source passes through the first collecting lens, further passes through the micron color separation plate and the extinction tube, and then is transmitted to the shielding secondary mirror at a certain divergence angle. The infrared light source is further transmitted to the wedge mirror through the shielding secondary mirror, and is output to the atmosphere by the wedge mirror at a certain inclination angle. The infrared light source interacts with the atmosphere to generate a backscattered light signal. The light signal enters the first collecting lens again via the wedge mirror, the shielding secondary mirror, and the micron spectroscopic color separation plate, and further enters the detection unit through the optical fiber. The detection unit receives the corresponding light signal and converts it into an electronic signal The signal is transmitted to the transient acquisition and recording system; the reflective system includes an ultraviolet primary mirror, an ultraviolet primary mirror seat, an extinction tube, a shielding secondary mirror, an aperture, a collecting lens 2, and a converging lens. The ultraviolet light source is controlled by the data processing and control system. After receiving the corresponding command, the ultraviolet light source is emitted to the atmosphere through the transmitting component. The ultraviolet laser interacts with the atmosphere to generate multi-path backscattered light signals. The multi-path optical signals can pass through the ultraviolet primary mirror and the shielding secondary mirror in turn and enter the micron spectrometer unit. The micron spectrometer unit transmits the optical signal into the collecting lens 2. The collecting lens 2 transmits the optical signal to the nano spectrometer unit through optical fiber. The nano spectrometer unit separates the optical signal into 6 channel signals, and connects the optical signals of the 6 channels to the detection unit respectively. The optical signal is converted into an electrical signal through the detection unit, and the electrical signal is further transmitted to the transient acquisition and recording system.

3. A low-altitude meteorological multi-parameter laser radar according to claim 2, characterized in that: The infrared light source differs from the ultraviolet light source by more than 1 micron.

4. A low-altitude meteorological multi-parameter laser radar according to claim 2 or 3, characterized in that: The shielding secondary mirror is composed of two surfaces, and the two surfaces of the ultraviolet primary mirror and the shielding secondary mirror satisfy the following geometric relationship: ， Among them, the distance between the UV primary mirror and the shielding secondary mirror is d, and the focal extension is , the center thickness of the shielding secondary mirror is t, the refractive index of the shielding secondary mirror material is n, and the radius of curvature of the lower surface of the shielding secondary mirror is , the curvature radius of the upper surface of the shielded secondary mirror is , the focal length of the obstructed secondary mirror is .

5. A low-altitude meteorological multi-parameter laser radar according to claim 2 or 3, characterized in that: The system shielding ratio of the reflective system is less than 1 / 4, the ultraviolet primary mirror is processed by a dielectric film process, and the reflectivity in a specific ultraviolet band is greater than 99.5%; a color separation film is added under the shielding secondary mirror, and the reflectivity in a specific ultraviolet band is greater than 99%, and the transmittance in a specific infrared band is greater than 99%; an infrared anti-reflection film is applied on the shielding secondary mirror, and the transmittance in a specific infrared band is greater than 99%; the surface accuracy of the wedge mirror, the shielding secondary mirror, and the reflecting primary mirror are all better than λ / 8.

6. The low-altitude meteorological multi-parameter laser radar according to claim 4, characterized in that: The infrared light source is transmitted to the micron spectrometer unit via optical fiber; the ultraviolet light source is directly emitted into the atmosphere via a transmitting component; both the micron spectrometer unit and the nano spectrometer unit reflect the infrared band and transmit the ultraviolet band, with the reflectivity and transmittance both being greater than 99%; both types of spectrometer units use optical fiber output, and the nano spectrometer unit further separates the ultraviolet band signal into 6 channels, with each two channels inverting a profile.

7. The low-altitude meteorological multi-parameter laser radar according to claim 6, characterized in that: The collecting lens 1 is equipped with a focusing ring, which can be focused forward and backward; the micron color separation plate adopts a high-stable fixing mechanism, which is adjustable in two dimensions; the three-leaf support is a double-layer structure, including a servo fixing frame and a shielding secondary mirror fixing frame, and the shielding secondary mirror is firmly connected to the shielding secondary mirror fixing frame. The servo system includes a driving motor and a gear pair, and the driving motor is fixedly arranged on the servo fixing frame. The wedge mirror is firmly connected to the wedge mirror seat and is fastened by the side, which does not affect the transmission area of ​​the wedge mirror; the driving motor drives the wedge mirror seat to rotate through the gear pair.

8. The low-altitude meteorological multi-parameter laser radar according to claim 7, characterized in that: The diameter of the ultraviolet primary mirror is greater than 300 mm, the focal length is greater than or equal to 2 m, and the outer diameter d of the servo system is less than 100 mm.

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