A multi-wavelength raman laser radar intelligent online calibration device

Abstract

The utility model relates to a kind of multi-wavelength Raman laser radar intelligent online calibration device, including laser calibration device being oppositely arranged with reflector, telescope, four quadrant device, linearity calibration device, subsequent light splitting device and be set on four quadrant device calibration emission light source and be set on the subsequent light splitting device subsequent calibration device are sequentially arranged, controller is connected with laser calibration device, four quadrant device, calibration emission light source, linearity calibration device and subsequent light splitting device respectively.The device integrates light source calibration, optical path calibration, linearity calibration, gain coefficient calibration and system constant calibration and other core function modules, deeply fusion in compact architecture, facilitate the installation deployment use of equipment, not only substantially improve calibration efficiency, reduce human operation failure, but also can adapt to complex and changeable atmospheric environment, realize equipment uninterrupted online calibration, ensure that laser radar always maintains high-precision detection performance in long-period operation.

Description

Technical Field

[0001] This utility model relates to a lidar, and more particularly to an intelligent online calibration device for a multi-wavelength Raman lidar. Background Technology

[0002] As a high-precision device in the field of atmospheric detection, the automated and intelligent calibration and quality control of multi-wavelength Raman lidar are crucial. In climate change research, accurate measurements of parameters such as atmospheric temperature, humidity, and aerosols are indispensable, and multi-wavelength Raman lidar can acquire atmospheric composition information by emitting laser pulses of different wavelengths, providing core data for these studies.

[0003] Existing calibration schemes mainly include:

[0004] 1. CCD-based automatic optical axis calibration uses a CCD camera to capture the emitted and received light spots, and a servo motor adjusts the reflector to achieve optical axis alignment. It relies on visible light-assisted calibration (such as a 650nm indicator laser), which differs from the radar operating wavelength (such as 1064nm), resulting in calibration errors.

[0005] 2. The linearity calibration of the stepped attenuator was carried out by using a motor-driven attenuation wheel to switch different attenuation ratios and establishing the relationship curve between the received signal and the light intensity. However, the nonlinear response of the detector (such as the gain jump of the PMT under low light intensity) was not considered.

[0006] 3. Rotating polarizer method: A stepper motor is used to drive the polarizer to rotate from 0° to 180°. The transmitted light intensity is measured to calculate the depolarization ratio. The mechanical rotation causes a polarization angle positioning error (±1°), and the depolarization ratio calculation error reaches 3%.

[0007] The above solutions typically use a single method to calibrate different parameters, resulting in separate calibration of multiple parameters, low efficiency, low integration, insufficient automation, and high manpower investment. Utility Model Content

[0008] To address the aforementioned problems, this utility model provides an intelligent online calibration device for multi-wavelength Raman lidar, the specific technical solution of which is as follows:

[0009] An intelligent online calibration device for multi-wavelength Raman lidar includes: a laser calibration device, positioned opposite a reflector, for analyzing the polarization direction, pointing differences, and energy changes of a laser beam; a telescope for receiving echo signals; a four-quadrant device, positioned in front of the telescope, for individually blocking or opening any one-quarter quadrant of the telescope; a calibration emission source, connected to the four-quadrant device, for measuring the laser polarization direction, laser polarization ratio, and laser energy changes; a linearity calibration device, positioned behind the telescope, for linear calibration; a subsequent beam splitter, positioned behind the linearity calibration device and opposite to the calibration emission source, for separating signals of different wavelengths or polarizations; a subsequent calibration device, positioned on the subsequent beam splitter, for monitoring changes in the transmittance of the subsequent optical path and changes in background light intensity; and a controller, which is connected to the laser calibration device, the four-quadrant device, the calibration emission source, the linearity calibration device, and the subsequent beam splitter.

[0010] Preferably, the laser calibration device includes: a laser beam sampling plate, disposed opposite to the reflector; a laser-level polarization beam splitter, disposed opposite to the laser beam sampling plate; and an energy meter, disposed opposite to the laser-level polarization beam splitter, for measuring the laser polarization ratio and continuously measuring the laser energy change.

[0011] Preferably, the four-quadrant device includes: a base with a circular detection cavity and an optical aperture communicating with the detection cavity; four fan-shaped cover plates arranged in a ring array on the top of the detection cavity; and a flipping assembly disposed on the base and connected to the fan-shaped cover plates for opening the fan-shaped cover plates.

[0012] Furthermore, the flipping assembly includes: a flipping motor disposed on the base; a rotating disk disposed on the flipping motor; and a connecting rod disposed on the rotating disk and connected to the fan-shaped cover plate.

[0013] Preferably, the calibrated emission light source includes: a light source housing with a light source cavity inside; LED beads disposed in the light source cavity; a filter disposed in the light source cavity and located above the LED beads; a first lens disposed above the filter; an optical fiber bundle assembly disposed in the light source cavity and positioned opposite to the first lens; and a light source emission end disposed on the light source housing and connected to the optical fiber bundle assembly and the four-quadrant device.

[0014] Preferably, the linearity calibration device includes: a calibration base; a lens clamping arm slidably disposed on the calibration base; a plurality of attenuation plates with different attenuation values ​​disposed on the lens clamping arm and arranged along the length direction of the lens clamping arm; and a movement drive assembly disposed on the calibration base and connected to the lens clamping arm for driving the lens clamping arm to move to realize the switching of the attenuation plates.

[0015] Furthermore, the moving drive assembly includes: a moving motor disposed on the calibration base; a reduction gear unit disposed on the calibration base and connected to the moving motor; and a rack disposed on the lens clamping arm and connected to the reduction gear unit.

[0016] Preferably, the subsequent calibration device includes: a calibration housing, having a calibration cavity and a first light-transmitting port and a second light-transmitting port communicating with the calibration cavity; a sampling lens, disposed in the calibration cavity and respectively opposite to the first light-transmitting port and the second light-transmitting port, for acquiring the light beam generated by the calibration emission light source for calibration or acquiring ambient light for background light intensity monitoring; a second lens, disposed in the calibration cavity and opposite to the sampling lens; and a phototube, disposed on the calibration housing and opposite to the second lens.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention provides an intelligent online calibration device for multi-wavelength Raman lidar, which, with its high integration and automation, reshapes the lidar calibration process. It integrates core functional modules such as light source calibration, optical path calibration, linearity calibration, gain coefficient calibration, and system constant calibration, deeply embedding them into a compact architecture. This facilitates the installation, deployment, and use of the equipment, significantly improving calibration efficiency, reducing human error, and adapting to complex and changing atmospheric environments. It enables uninterrupted online calibration, ensuring the lidar maintains high-precision detection performance during long-term operation, providing reliable data support for atmospheric science research and environmental monitoring, while effectively reducing maintenance costs, demonstrating strong technological advantages and application value.

[0019] This invention provides an intelligent online calibration device for multi-wavelength Raman lidar, integrating functional modules such as light source calibration, optical path calibration, linearity calibration, gain coefficient calibration, and system constant calibration. It can automatically determine and adjust the signal direction of the receiving channel, accurately determine the matching degree between the meter channel signal and the corresponding Raman channel signal based on the consistency between the far-field and near-field signals, and achieve optical path calibration. It can comprehensively test the linearity of the receiving system, and during the linearity verification process, it can also accurately check the accuracy of the signal baseline under weak signal conditions, thereby ensuring that the entire receiving system can operate stably and accurately under different signal strength environments. Through dynamic polarization adjustment, while detecting the channel depolarization isolation, it can obtain the dynamic gain ratio under different attenuation configurations, which helps to effectively cope with drastic environmental changes, reduce signal inversion anomalies caused by environmental fluctuations, and effectively ensure data reliability. By monitoring the data of each channel in real time, this method can accurately calculate the radar constant correction coefficient, providing key parameter support for lidar to achieve accurate detection. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this application;

[0021] Figure 2 This is a schematic diagram of the laser calibration device;

[0022] Figure 3 This is a schematic diagram of the four-quadrant device;

[0023] Figure 4 This is a schematic diagram of the structure for calibrating the emission source;

[0024] Figure 5 This is a schematic diagram of the internal structure of the calibrated emission source;

[0025] Figure 6 This is a schematic diagram of the linearity calibration device;

[0026] Figure 7 This is the optical path diagram of the subsequent calibration device;

[0027] Figure 8 This is a schematic diagram of the subsequent calibration device;

[0028] Figure 9 This is a schematic diagram of the subsequent beam splitting device. Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] like Figures 1 to 9As shown, an intelligent online calibration device for multi-wavelength Raman lidar includes a controller, a laser calibration device 102, a telescope 106, a four-quadrant device 101, a calibration emission source, a linearity calibration device 103, a subsequent beam splitter 107, and a subsequent calibration device 104. The laser calibration device 102 is positioned opposite to a reflector and is used to analyze the polarization direction, pointing differences, and energy changes of the laser beam. The four-quadrant device 101, the telescope 106, the linearity calibration device 103, and the subsequent beam splitter 107 are connected sequentially. The subsequent calibration device 104 is mounted on the subsequent beam splitter 107; the telescope 106 is used to receive echo signals; the four-quadrant device 101 is used to individually block or open any one-quarter quadrant of the telescope 106; the calibration emission source is used to measure the laser polarization direction, laser polarization ratio, and continuously measure the laser energy change; the linearity calibration device 103 is used for linear calibration; the subsequent beam splitter 107 is used to separate signals of different wavelengths or polarizations; the subsequent calibration device 104 is used to monitor the changes in the transmittance of the subsequent optical path and the changes in the background light intensity. The controller is connected to the laser calibration device 102, the four-quadrant device 101, the calibration emission source, the linearity calibration device 103, and the subsequent beam splitter 107, respectively.

[0031] Laser 105 emits a laser beam, which is incident into the atmosphere through a mirror assembly. A sample laser beam is obtained by the sampler of laser calibration device 102, and the polarization direction, pointing differences, and energy changes of the laser beam are analyzed. The echo signal is collected by telescope 106. A four-quadrant device 101, located above telescope 106, is used for four-quadrant calibration and integrates the emitting light source for subsequent calibration. Linearity calibration device 103, located between telescope 106 and subsequent optics, performs linearity calibration using lenses with different attenuation coefficients. In subsequent beam splitting device 107, signals of different wavelengths are separated and sequentially enter their corresponding channels. Before entering the detector, the signals pass through a sample extractor, and the sample signals enter subsequent calibration device 104.

[0032] like Figure 2As shown, the laser calibration device 102 includes a laser beam sampling plate 401, a laser-grade polarizing beam splitter prism, and an energy meter 403 arranged sequentially. The laser beam sampling plate 401 is positioned opposite to a reflector, and the energy meter 403 is used to measure the laser polarization ratio and continuously measure the laser energy change. The laser calibration device 102 is located in the laser beam path. The laser beam sampling plate 401 is a UV-grade fused silica sheet. On the laser incident surface, it is uncoated with a surface finish equal to or better than 10⁻⁵. On the laser exit surface, it is coated with an antireflection film with high laser wavelength transmittance, and the transmittance is higher than 99.5%. The laser-grade polarizing beam splitter prism 402 has a polarization separation degree of more than 1000:1 at a specific wavelength. The bottom of the laser-grade polarizing beam splitter prism contains an electrically rotatable base for calibrating the laser polarization direction. The laser beam separated by the laser-grade polarizing beam splitter prism is incident on the surface of the energy meter 403, which can measure the laser polarization ratio and continuously measure the laser energy change.

[0033] Laser polarization ratio calibration process: After the laser beam passes through the laser beam sampling plate, the sample beam is acquired by two energy meters 403 through the laser-level polarization beam splitter, and the P-polarization energy is compared with the S-polarization energy.

[0034] Laser energy calibration process: The energy meter 403 continuously monitors the laser energy in the P-polarization direction and performs RMS calculation on the laser energy stability over a period of time. When the deviation exceeds the threshold, the system adjusts the configuration parameters to stabilize the laser again.

[0035] like Figure 3 As shown, the four-quadrant device 101 includes a base 201, four sector-shaped cover plates 202, and a flipping assembly. The base 201 has a circular detection cavity inside, and a light hole 208 communicating with the detection cavity is provided on the side of the base 201. The four sector-shaped cover plates 202 are arranged in a circular array on the top of the detection cavity. The flipping assembly is mounted on the base 201 and connected to the sector-shaped cover plates 202 for opening the sector-shaped cover plates 202. The flipping assembly includes a flipping motor 205, a rotating disk 204, and a connecting rod 203. The flipping motor 205 is fixed to the outer circular surface of the base 201, and four motors are provided. The rotating disk 204 is fixed to the motor shaft of the flipping motor 205 and connected to the connecting rod 203. The connecting rod 203 is L-shaped and is also connected to the sector-shaped cover plates 202.

[0036] Four sector-shaped covers 202 divide the circular receiving area, forming the basic structure of the four-quadrant device 101. The opening and closing of the sector-shaped covers 202 is achieved by rotating a flip motor 205, thereby controlling the signal receiving status of each quadrant area. The flip motor 205 is mounted on the base 201 via a motor fixing component 206, and the base 201 is connected to the telescope 106 via a base 201 fixing component, thus maintaining the relative fixation of each quadrant position. The aperture 208 is a channel reserved for the light source device. The controller controls the flip motor 205 via serial communication to complete the opening and closing of a single quadrant cover.

[0037] The laser beam emitted by the laser can obtain independent signals in four directions through the control of the four-quadrant device 101. Through consistency calculation, the consistency of the light path direction can be confirmed. When the four-quadrant calculation value exceeds the threshold, the automatic adjustment process is started. After each quadrant plate starts collecting independent data, the reflector group and its corresponding direction are finely adjusted according to their respective deviation amplitude. The above operation is repeated until the four quadrants meet the threshold requirements.

[0038] like Figure 4 and Figure 5 As shown, the calibrated emission light source includes a light source housing 307, LED beads 301, a filter 302, a first lens 303, an optical fiber bundle assembly 304, and a light source emitting end 306. The light source housing 307 has a light source cavity inside. The LED beads 301 are installed at the bottom of the light source cavity and are positioned opposite to the filter 302. The filter 302 is installed inside the light source cavity via a support frame 304. The first lens 303 is installed on the support frame 304 and is located above the filter 302. The optical fiber bundle assembly 304 is located inside the light source cavity and is positioned opposite to the first lens 303 and the light source emitting end 306. The light source emitting end 306 is installed on the light source housing 307 and is connected to the four-quadrant device 101.

[0039] The light emitted by the LED bead 301 is filtered by the filter 302 and coupled into the interior of the fiber optic bundle assembly 304 by the first lens 303, and then emitted from the light source emitting end 306. After leaving the optical fiber, the light source is collimated again and homogenized by the frosted glass. The light source housing 307 is locked to the four-quadrant device 101 through the positioning hole, and the light source emitting end 306 enters the radar receiving area through the light aperture 208.

[0040] LED beads 301 include light source beads of all wavelengths distinguished in the subsequent beam splitting device 107. Filter 302 and first lens 303 purify the light beam emitted by LED beads 301 and couple it into the optical fiber. The optical fiber bundle assembly 304 ensures that all light sources are output through the same optical fiber. At the output end of the optical fiber, the beam is collimated by the same lens, and frosted glass 305 made of N-BK7 glass is disposed at the light source emitting end 306 to homogenize the output beam.

[0041] Gain ratio calibration process: The emitting end 306 of the calibrated emission source is positioned in the four-quadrant device 101 so that its emission source surface is approximately perpendicular to the receiving surface of the telescope 106. According to the calibration channel, such as 532 depolarization, the 532nm LED light source is made to emit light. Due to the homogenization of the light source, the 532 horizontal polarization channel and the 532 vertical polarization channel obtain the same energy, and the polarization state is similar to that of natural light. The gain ratio value of the polarization channel is obtained according to the signal intensity fed back by the detector.

[0042] The light source emitting end 306 can be inserted into the four-quadrant device 101 through the light hole 208 during operation via the telescopic device, and can be withdrawn from the light hole 208 via the telescopic device after operation.

[0043] like Figure 6As shown, the linearity calibration device 103 includes a calibration base 501, a lens clamping arm 502, attenuators 503, and a movement drive assembly. The lens clamping arm 502 is slidably mounted on the calibration base 501. Several attenuators 503 are provided, each with a different attenuation value. The attenuators 503 are sequentially fixed on the lens clamping arm 502 along its length. The movement drive assembly is mounted on the calibration base 501 and connected to the lens clamping arm 502, used to drive the lens clamping arm 502 to move and switch the attenuators 503. The movement drive assembly includes a movement motor 504, a reduction gear unit 506, and a rack. The movement motor 504 is fixed to the bottom of the calibration base 501 via a motor connector 505. The reduction gear unit 506 includes multiple gears that mesh sequentially. The input gear of the reduction gear unit 506 is fixed to the motor shaft of the moving motor 504, and the output gear of the reduction gear unit 506 meshes with a rack. The rack is fixed to the lens clamping arm 502 and is arranged along its length. The moving motor 504 is also connected to a controller. The moving motor 504 drives the rack through the reduction gear unit 506, and the rack drives the lens clamping arm 502 to move, thereby switching the attenuator 503. The lens clamping arm 502 is also equipped with rollers, which are located on both sides, top, and bottom of the lens clamping arm 502, creating rolling friction between the lens clamping arm 502 and the calibration base 501. The lens clamping arm 502 and the calibration base 501 can also be connected by a linear guide pair to ensure the stability of the lens clamping arm 502 during movement. The movement of the lens clamping arm 502 enables the switching of lenses with different transmittances in the subsequent beam splitting device 107.

[0044] The linearity calibration device 103 is located before the main optical path of the subsequent beam splitter 107. It drives the lens clamping arm 502 through the main optical path of the subsequent beam splitter 107 to complete the linearity measurement. It is equipped with different attenuation lenses. Due to the difference between different wavelengths, metal-coated attenuation plates 503 are required, and the OD value of each plate needs to be calibrated individually. For 532nm, the transmittance of the attenuation plate 503 is between 100% and 10%, with typical distributions of 100%, 80%, 50%, 30%, and 20%. This device can not only determine linearity but also be used to determine the degree of signal saturation.

[0045] Linearity calibration process: The laser emits a laser beam, and by controlling the linearity calibration device 103, signals with different attenuation amplitudes can be obtained.

[0046] like Figure 7 and Figure 8As shown, the subsequent calibration device 104 is located at the end of the subsequent beam splitter 107. The subsequent calibration device 104 includes a calibration housing 605, a sampling lens 601, a second lens 602, and a phototube 603. The calibration housing 605 has a calibration cavity inside, and a first light-transmitting port and a second light-transmitting port communicating with the calibration cavity are also provided on the calibration housing 605. The first light-transmitting port and the second light-transmitting port correspond to the bottom end of each branch channel in the subsequent beam splitter 107, respectively, and are connected to the subsequent optics and detector, and are fixed by associated holes. The sampling lens 601 is installed in the calibration cavity and is respectively arranged opposite to the first light-transmitting port and the second light-transmitting port. It is used to acquire the beam generated by the emission source for calibration or to acquire ambient light for background light intensity monitoring. The second lens 602 is installed in the calibration cavity and is arranged opposite to the sampling lens 601. The phototube 603 is fixed on the calibration housing 605 and is arranged opposite to the second lens 602. The sampling lens 601 is a KrF-grade fused silica sheet. Its incident surface is uncoated with a surface finish equal to or better than 10⁻⁵. Its exit surface is coated with a high-transmittance anti-reflection film for laser wavelengths, achieving a transmittance higher than 99.5%. The second lens 602 is a focusing lens with a double-sided broadband anti-reflection coating and a focal length of 30mm. The light beam passing through the sampling lens 601 is focused onto the phototube 603 by the focusing lens to monitor changes in subsequent light path transmittance and background light intensity. The light beam reflected by the sampling lens 601 is focused by the second lens 602 and then incident on the phototube 603. Both the second lens 602 and the phototube 603 are located above the sampling lens 601, and the phototube 603 is fixed by a retaining ring 604.

[0047] Radar constant calibration process: First, laser energy calibration is performed. Then, the LED beads 301 in the calibration emission light source are turned on. At the end of the radar system, the light transmittance of the subsequent channel and the signal value of the channel can be obtained through the subsequent calibration device 104. The energy correction coefficient, the subsequent optical transmittance correction coefficient and the PMT quantum efficiency correction coefficient can be obtained respectively, thereby correcting the radar constant.

[0048] The laser radar emits three wavelength lasers: 1064nm, 532nm, and 355nm. A set of reflectors is placed at the laser emission end to adjust the emission angle of the laser beam. The set consists of a reflector and an electric adjustment frame. The direction of the laser beam can be adjusted by the control device of the electric adjustment frame.

[0049] Telescope 106 is used to receive echo signals, and is usually a Newtonian telescope 106 or a Cassegrain telescope 106.

[0050] The subsequent beam splitter 107 is a device for separating signals of different wavelengths or polarizations, comprising different types of beam splitters and filters, which is existing technology, such as... Figure 9The beam splitting module in the receiving system of CN119667715A shown is used to separate beams of different wavelengths or different polarization properties.

[0051] An intelligent online calibration device for multi-wavelength Raman lidar has the following advantages:

[0052] 1. Through the integrated design of multiple calibration devices, light source calibration, optical path calibration, linearity verification, dynamic range testing, gain coefficient calibration, depolarization ratio calculation, and system constant calibration echo signal reference can be realized simultaneously; the system constant calibration is measured by the integrated subsequent calibration device 104, laser calibration device 102, and calibration emission light source.

[0053] 2. Intelligent and automated calibration: It solves the problem of data interruption in the calibration process, adopts an intelligent calibration method, is not limited by space or time, and can complete automated calibration at any time, ensuring data reporting rate and avoiding the problems of high labor costs and limited calibration cycle;

[0054] 3. Improve calibration accuracy and efficiency: The integrated high-precision calibration device can improve the inversion accuracy during long-term data acquisition through regular calibration and correction, avoid manual calibration errors, improve the stability and accuracy of data results, and ensure the long-term stable and reliable operation of the equipment.

[0055] This device, with its highly integrated and automated features, redefines the lidar calibration process. It integrates core functional modules such as light source calibration, optical path calibration, linearity calibration, gain coefficient calibration, and system constant calibration, deeply embedding them into a compact architecture for easy installation, deployment, and use. Equipped with an intelligent control system, the device can autonomously complete the entire calibration process from signal acquisition and analysis to parameter adjustment, eliminating the need for frequent manual intervention. This not only significantly improves calibration efficiency and reduces human error but also adapts to complex and changing atmospheric environments, enabling uninterrupted online calibration. This ensures that the lidar maintains high-precision detection performance during long-term operation, providing reliable data support for atmospheric science research and environmental monitoring, while effectively reducing maintenance costs, demonstrating strong technological advantages and application value.

[0056] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without inventive effort, and these embodiments will all fall within the protection scope of the claims of this utility model.

Claims

1. An intelligent online calibration device for multi-wavelength Raman lidar, characterized in that, include: A laser calibration device (102) is set opposite to the reflector and is used to analyze the polarization direction, pointing difference and energy change of the laser beam; Telescope (106) is used to receive echo signals; A four-quadrant device (101) is provided in front of the telescope (106) for individually blocking or opening any one-quarter quadrant of the telescope (106). The emission source is calibrated and connected to the four-quadrant device (101) for measuring the laser polarization direction, laser polarization ratio and laser energy change; A linearity calibration device (103) is located behind the telescope (106) and is used for linear calibration; A subsequent beam splitter (107) is located behind the linearity calibration device (103) and is positioned opposite to the calibration emission light source, and is used to separate signals of different wavelengths or polarizations. A subsequent calibration device (104), mounted on the subsequent beam splitter (107), is used to monitor changes in the transmittance of the subsequent optical path and changes in the background light intensity; and The controller is connected to the laser calibration device (102), the four-quadrant device (101), the calibration emission light source, the linearity calibration device (103), and the subsequent beam splitting device (107), respectively.

2. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 1, characterized in that, The laser calibration device (102) includes: The laser beam sampling plate (401) is positioned opposite to the reflector; A laser-grade polarizing beam splitter (402) is disposed opposite to the laser beam sampling plate (401); and An energy meter (403) is positioned opposite the laser-grade polarization beam splitter (402) and is used to measure the laser polarization ratio and continuously measure the laser energy change.

3. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 1, characterized in that, The four-quadrant device (101) includes: The base (201) has a circular detection cavity inside and an optical hole (208) communicating with the detection cavity. Four fan-shaped cover plates (202) are arranged in a ring array on the top of the detection cavity; A flipping component is disposed on the base (201) and connected to the fan-shaped cover plate (202) for opening the fan-shaped cover plate (202).

4. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 3, characterized in that, The flipping component includes: A flip motor (205) is mounted on the base (201); A rotating disk (204) is mounted on the tilting motor (205); and A connecting rod (203) is provided on the rotating disk (204) and connected to the fan-shaped cover plate (202).

5. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 1, characterized in that, The calibrated emission light source includes: The light source housing (307) has a light source cavity inside; LED beads (301) are disposed within the light source cavity; A filter (302) is disposed in the light source cavity and located above the LED bead (301); The first lens (303) is disposed above the filter (302); An optical fiber combiner assembly (304) is disposed within the light source cavity and is positioned opposite to the first lens (303); and The light source emitting end (306) is disposed on the light source housing (307) and connected to the optical fiber bundle assembly (304) and the four-quadrant device (101).

6. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 1, characterized in that, The linearity calibration device (103) includes: Calibration mount (501); The lens clamping arm (502) is slidably mounted on the calibration base (501); A plurality of attenuation plates (503) with different attenuation values ​​are disposed on the lens clamping arm (502) and arranged along the length direction of the lens clamping arm (502); and A moving drive assembly is disposed on the calibration base (501) and connected to the lens clamping arm (502) for driving the lens clamping arm (502) to move in order to switch the attenuator (503).

7. The intelligent online calibration device for a multi-wavelength Raman lidar according to claim 6, characterized in that, The mobile drive component includes: A movable motor (504) is mounted on the calibration base (501); A reduction gear unit (506) is mounted on the calibration base (501) and connected to the moving motor (504); and A rack is provided on the lens clamping arm (502) and connected to the reduction gear unit (506).

8. The intelligent online calibration device for multi-wavelength Raman lidar according to claim 1, characterized in that, The subsequent calibration device (104) includes: The calibration box (605) is provided with a calibration cavity and a first light-transmitting port and a second light-transmitting port communicating with the calibration cavity; A sampling lens (601) is disposed in the calibration cavity and is respectively positioned opposite to the first light-transmitting port and the second light-transmitting port. It is used to acquire the light beam generated by the calibration emission light source and perform calibration or to acquire ambient light for background light intensity monitoring. A second lens (602) is disposed within the calibration cavity and is positioned opposite to the sampling lens (601); and A phototube (603) is disposed on the calibration box (605) and is disposed opposite to the second lens (602).

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