A three-wavelength multi-channel lidar system

Abstract

The invention discloses a three-wavelength multi-channel laser radar system, comprising: a cabin and an optical transmitting system, a receiving spectroscopic system, a data acquisition system and an industrial computer installed in the cabin, wherein a skylight is arranged on the top of the cabin; the optical transmitting system comprises a seed injection laser, a double frequency crystal module, a triple frequency crystal module, a beam expander group and a reflector group; the receiving spectroscopic system comprises a telescope, a subsequent optical component and a spectroscopic component; the data acquisition system comprises an acquisition card and a photoelectric sensor component. The invention overcomes the shortcomings of the prior art, and each component of the system can work stably and can emit three lasers of different wavelengths, and after being split by the receiving spectroscopic system, the lasers are divided into six groups, and after being filtered by filter components with different functions, multi-channel detection is realized, and water vapor, aerogel, cloud, particles and dust can be observed in an integrated manner.

Description

Technical Field

[0001] The present invention relates to the field of laser radar technology, and in particular to a three-wavelength multi-channel laser radar system. Background Art

[0002] Lidar (Light Detection And Ranging) uses laser as light source and detects echo signals generated by the interaction between laser and atmosphere to remotely sense the atmosphere. It has high-precision distance resolution capability. The interaction between laser and atmosphere will produce radiation signals containing information about gas atoms, molecules, atmospheric aerosol particles and clouds. The corresponding inversion method can be used to obtain information about atmospheric components such as gas atoms, molecules, atmospheric aerosol particles and clouds.

[0003] At the same time, lidar can obtain information such as atmospheric temperature profile, atmospheric humidity profile, ozone profile, etc. It is an indispensable monitoring equipment in the meteorological and environmental protection industries, and its application prospects are becoming more and more broad.

[0004] It adopts multi-wavelength emission and multi-channel detection, and can integrate multi-parameter observations such as water vapor and aerosols (particulate matter, dust, clouds, etc.). Summary of the invention

[0005] The purpose of the present invention is to provide a three-wavelength multi-channel laser radar system to overcome the shortcomings of the prior art.

[0006] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0007] A three-wavelength multi-channel laser radar system comprises: a cabin and an optical transmitting system, a receiving spectroscopic system, a data acquisition system and an industrial computer installed in the cabin, wherein a skylight is provided on the top of the cabin;

[0008] The optical emission system comprises: a seed injection laser, a frequency doubling crystal module, a frequency tripling crystal module, a beam expander group and a reflector group. The laser emitted by the seed injection laser passes through the frequency doubling crystal module, the frequency tripling crystal module, the beam expander group, the reflector group and the skylight in sequence and enters the atmosphere. The seed injection laser is electrically connected to an industrial control machine.

[0009] The receiving spectroscopic system comprises: a telescope, a subsequent optical component and a spectroscopic component. The subsequent optical component is arranged behind the telescope. The light received by the telescope is processed and transmitted to the spectroscopic component. The spectroscopic component divides the collimated laser into six groups of light.

[0010] The data acquisition system includes an acquisition card and a photoelectric sensor assembly. The photoelectric sensor assembly includes five first photoelectric sensors composed of filter assemblies and photomultiplier tubes and one second photoelectric sensor composed of filter assemblies and avalanche photodiodes. The six groups of light correspond to a first photoelectric sensor or a second photoelectric sensor respectively. The first photoelectric sensor and the second photoelectric sensor are electrically connected to the acquisition card, and the acquisition card is electrically connected to an industrial computer.

[0011] Among them, the laser emitted by the seed injection laser is divided into three beams of laser with wavelengths of 355nm, 532nm and 1064nm respectively through a doubled frequency crystal module and a tripled frequency crystal module, the beam expander group includes three beam expanders, and the reflector group includes three reflection groups each consisting of two third reflectors, and each reflection group corresponds to a wavelength of laser and a beam expander.

[0012] The reflectivity of the reflection group to the laser of the corresponding wavelength is greater than 99%, and the threshold value is greater than 10J / cm 2 .

[0013] Wherein, the seed injection laser is a laser with a single pulse energy greater than 100 mJ, the beam expander has a beam expansion multiple greater than 5 times, and the light transmission efficiency is ≥95%.

[0014] The aperture of the telescope is not less than 16 inches, and the reflectivity of the primary and secondary mirror coatings of the telescope to the laser of the corresponding wavelength of the receiving channel is not less than 90%.

[0015] The subsequent optical component includes a grating, a first reflector and a collimating lens. The grating filters the light received by the telescope and reflects it to the collimating lens through the first reflector, collimates the divergent light signal, and then enters the spectroscopic component.

[0016] Wherein, the spectroscopic component includes a first spectroscope, a second spectroscope, a third spectroscope, a fourth spectroscope, a polarizing prism and a second reflector. The first spectroscope divides the light from the subsequent optical component into a first light path and a second light path. The second light path reaches the second spectroscope and is divided into a third light path and a fourth light path. The third light path and the fourth light path enter two first photoelectric sensors respectively. The first light path reaches the third spectroscope and is divided into a fifth light path and a sixth light path. The fifth light path enters a second photoelectric sensor. The sixth light path reaches the third spectroscope and is divided into a seventh light path and an eighth light path. The seventh light path enters a first photoelectric sensor. The eighth light path reaches the fourth spectroscope and is divided into a ninth light path and a tenth light path. The ninth light path enters a first photoelectric sensor. The tenth light path reaches the second reflector and is reflected to a first photoelectric sensor.

[0017] Among them, the reflectivity of the first beam splitter to 660nm light is greater than 90%, and the transmittance to 607nm light is greater than 95%; the reflectivity of the second beam splitter to 660nm light is greater than 95%; the transmittance of the third beam splitter to 607nm light is greater than 95%, and the reflectivity to 1064nm light is greater than 90%; the reflectivity of the fourth beam splitter to 607nm light is greater than 95%, and the transmittance to 532nm light is greater than 95%; the polarizing prism is a 532nm polarizing beam splitter.

[0018] Among them, the optical channel of the first photoelectric sensor corresponding to the third light is the 355nm signal channel, the optical channel of the first photoelectric sensor corresponding to the fourth light is the 660nm channel, the optical channel of the second photoelectric sensor corresponding to the fifth light is the 1064nm channel, the optical channel of the first photoelectric sensor corresponding to the seventh light is the 608nm channel, the optical channel of the first photoelectric sensor corresponding to the ninth light is the 532nm-S channel, and the optical channel of the first photoelectric sensor corresponding to the tenth light is the 532nm-P channel.

[0019] Wherein, the filter assembly comprises a converging lens and a filter, wherein the filter bandwidth is less than 1nm and the transmittance is greater than 50%.

[0020] Wherein, the seed injection laser further comprises an energy monitoring module and a frequency monitoring module, and the energy monitoring module and the frequency monitoring module are electrically connected to the industrial control machine.

[0021] Among them, a skylight is provided on the top of the cabin, and a cleaning and demisting device is also installed on the skylight, and the cleaning and demisting area of ​​the cleaning and demisting device is not less than 0.3 square meters.

[0022] Wherein, a temperature control system is also installed in the storage compartment, and the temperature control system is electrically connected to the industrial control machine.

[0023] Wherein, the square cabin adopts thermal insulation material, and the thickness of the square cabin is not less than 75mm.

[0024] Wherein, the square cabin adopts thermal insulation material, and the thickness of the square cabin is 100mm.

[0025] Compared with the prior art, the implementation effects of the present invention are as follows: the system can control the temperature in the cabin, so that each component can work in a suitable environment, ensuring the stability of each component, and the cabin uses heat-insulating materials, so that the cabin has a good thermal insulation effect; the system can emit three lasers of different wavelengths, and after being split by a receiving spectroscopic system, it is divided into six groups, and after filtering by filter components with different functions, multi-channel detection is realized, and water vapor, aerogel, cloud, particles and dust can be observed in an integrated manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the system of the present invention. DETAILED DESCRIPTION

[0027] 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.

[0028] like Figure 1 As shown, a three-wavelength multi-channel laser radar system of the present invention includes a cabin 1 and an optical transmitting system, a receiving spectroscopic system, a data acquisition system and an industrial computer 16 installed in the cabin 1. A skylight is provided on the top of the cabin 1. The backscattered signal generated by the laser emitted by the optical transmitting system after entering the atmosphere through the skylight is received by the receiving spectroscopic system, and then enters the data acquisition system after processing and spectroscopic analysis. Finally, the industrial computer 16 records and processes the data collected by the data acquisition system. In addition, a cleaning and demisting device 3 is installed on the skylight to provide necessary conditions for the emission and reception of the laser. The cleaning and demisting area of ​​the cleaning and demisting device 3 is 0.5m 2 A temperature control system 2 is also installed in the cabin. The temperature control system 2 uses air conditioning and is powered by an external power supply. It can control the temperature in the cabin and provide a stable environment for the operation of the laser radar system.

[0029] The square cabin 1 is made of heat-insulating materials, and the thickness of the square cabin 1 is 100 mm, so that the square cabin 1 has a good heat-insulating effect.

[0030] The optical emission system of the system includes: a seed injection laser 4, a double frequency crystal module 5, a triple frequency crystal module 6, a beam expander group and a reflector group. The seed injection laser 4 is a laser with a single pulse energy greater than 100mJ. The laser emitted by the seed injection laser 4 passes through the double frequency crystal module 5, the triple frequency crystal module 6, the beam expander group and the reflector group in sequence, and then passes through the skylight into the atmosphere; the models of the double frequency crystal module 5 and the triple frequency crystal module 6 are Surelite 619-2700 and Surelite 619-2720, the beam expansion multiple of the beam expander 7 is greater than 5 times, and the light transmission efficiency is ≥95%; the seed injection laser 4 also includes an energy monitoring module 41 and a frequency monitoring module 42, and the seed injection laser 4, the energy monitoring module 41 and the frequency monitoring module 42 are electrically connected to the industrial computer 16. While the seed injection laser 4 emits laser light, the energy monitoring module 41 and the frequency monitoring module 42 provide real-time data feedback, so that the industrial computer 16 can understand the status of the seed injection laser 4 in real time.

[0031] The laser emitted by the seed injection laser 4 is divided into three laser beams with wavelengths of 355nm, 532nm and 1064nm respectively through the double frequency crystal module 5 and the triple frequency crystal module 6. The beam expander group includes three beam expanders 7. The reflector group includes three reflector groups each consisting of two third reflectors 10. The third reflector 10 is installed on a two-dimensional adjustment seat 11. The two-dimensional adjustment seat 11 is electrically connected to the industrial computer 16. The position of the third reflector can be adjusted by the industrial computer 16. The reflectivity of the reflector group to the laser of the corresponding wavelength is greater than 99%, and the threshold value is greater than 10J / cm 2 , each reflection group corresponds to a wavelength of laser and a beam expander 7.

[0032] The receiving spectroscopic system includes: a telescope 8, a subsequent optical component and a spectroscopic component. The telescope 8 adopts a Cassegrain system and has an active heat dissipation system. The telescope has an aperture of 16 inches. The primary mirror coating needle 81 and the secondary mirror coating needle 82 of the telescope 8 have a reflectivity of not less than 90% for the laser of the wavelength corresponding to the receiving channel. The subsequent optical component is arranged behind the telescope 8. The subsequent optical component includes a grating 20, a first reflector 21 and a collimating lens 22. The first reflector is mounted on a three-dimensional adjustment seat 12. The three-dimensional adjustment seat 12 is electrically connected to an industrial computer 16. The position of the first reflector 21 can be adjusted by the industrial computer 16 to obtain a better reflection effect. The grating 20 filters the light received by the telescope 8. The strong sunlight is suppressed, and the light is reflected to the collimating lens 22 by the first reflector 21. The divergent light signal is collimated and then enters the spectroscopic component. The spectroscopic component divides the collimated laser into six groups of light.

[0033] The light splitting component includes a first light splitter 23, a second light splitter 24, a third light splitter 25, a fourth light splitter 26, a polarizing prism 27 and a second reflector 28, and the first light splitter 23, the second light splitter 24, the third light splitter 25, the fourth light splitter 26, the polarizing prism 27 and the second reflector 28 are respectively mounted on a two-dimensional adjustment seat 11, and the two-dimensional adjustment seat 11 is electrically connected to an industrial computer 16. The data acquisition system includes an acquisition card 9 and a photoelectric sensor component, the photoelectric sensor component includes five first photoelectric sensors consisting of a filter component 30 and a photomultiplier tube 31 and a second photoelectric sensor consisting of a filter component 30 and an avalanche photodiode 32, the filter component 30 includes a converging lens and a filter, the filter bandwidth is less than 1nm, and the transmittance is greater than 50%.

[0034] The six groups of light correspond to a first photoelectric sensor or a second photoelectric sensor respectively. The first photoelectric sensor and the second photoelectric sensor are electrically connected to the acquisition card 9 , and the acquisition card 9 is electrically connected to the industrial computer 16 .

[0035] The first beam splitter 23 of the beam splitting component splits the light from the collimating lens 22 into a first light path and a second light path. The second light path reaches the second beam splitter 24 and is split into a third light path and a fourth light path. The third light path and the fourth light path enter two first photoelectric sensors respectively. The first photoelectric sensor converts the optical signal into a digital signal. The digital signal is collected by the acquisition card 9, and then the acquisition card 9 transmits the data to the industrial computer 16 for analysis and processing; the first light path reaches the third beam splitter 25 and is split into a fifth light path and a sixth light path. The fifth light path enters a second photoelectric sensor. The second photoelectric sensor converts the optical signal into a digital signal. The digital signal is collected by the acquisition card 9, and then the acquisition card 9 transmits the data to the industrial computer 16 for analysis and processing; the sixth light path reaches the third beam splitter 25 and is split into a seventh light path and an eighth light path. The seventh light path enters a first photoelectric sensor The first photoelectric sensor converts the optical signal into a digital signal, which is collected by the acquisition card 9, and then the acquisition card 9 transmits the data to the industrial computer 16 for analysis and processing; the eighth light reaches the fourth spectroscope 26 and is divided into the ninth light and the tenth light, the ninth light enters a first photoelectric sensor, the first photoelectric sensor converts the optical signal into a digital signal, which is collected by the acquisition card 9, and then the acquisition card 9 transmits the data to the industrial computer 16 for analysis and processing; the tenth light reaches the second reflector 2828 and is reflected to a first photoelectric sensor, the first photoelectric sensor converts the optical signal into a digital signal, which is collected by the acquisition card 9, and then the acquisition card 9 transmits the data to the industrial computer 16 for analysis and processing; multiple groups of data are finally transmitted from the acquisition card 9 to the industrial computer 16, and then inverted by corresponding algorithms to obtain a series of atmospheric parameters.

[0036] The reflectivity of the first beam splitter 23 to 660nm light is greater than 90%, and the transmittance to 607nm light is greater than 95%; the reflectivity of the second beam splitter 24 to 660nm light is greater than 95%; the transmittance of the third beam splitter 25 to 607nm light is greater than 95%, and the reflectivity to 1064nm light is greater than 90%; the reflectivity of the fourth beam splitter 26 to 607nm light is greater than 95%, and the transmittance to 532nm light is greater than 95%; the polarizing prism 27 is a 532nm polarizing beam splitter.

[0037] The six groups of light divided by the light splitting component refer to the third light, the fourth light, the fifth light, the seventh light, the ninth light and the tenth light. Among them, the optical channel of the first photoelectric sensor corresponding to the third light is the 355nm signal channel, the optical channel of the first photoelectric sensor corresponding to the fourth light is the 660nm channel, the optical channel of the second photoelectric sensor corresponding to the fifth light is the 1064nm channel, the optical channel of the first photoelectric sensor corresponding to the seventh light is the 608nm channel, the optical channel of the first photoelectric sensor corresponding to the ninth light is the 532nm-S channel, and the optical channel of the first photoelectric sensor corresponding to the tenth light is the 532nm-P channel.

[0038] 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 three-wavelength multi-channel laser radar system, characterized in that: include: A shelter and an optical transmitting system, a receiving spectroscopic system, a data acquisition system and an industrial computer installed in the shelter, wherein a skylight is provided on the top of the shelter; The optical emission system comprises: a seed injection laser, a frequency doubling crystal module, a frequency tripling crystal module, a beam expander group and a reflector group. The laser emitted by the seed injection laser passes through the frequency doubling crystal module, the frequency tripling crystal module, the beam expander group, the reflector group and the skylight in sequence and enters the atmosphere. The seed injection laser is electrically connected to an industrial control machine. The receiving spectroscopic system comprises: a telescope, a subsequent optical component and a spectroscopic component. The subsequent optical component is arranged behind the telescope, and processes the light received by the telescope and transmits it to the spectroscopic component. The spectroscopic component divides the collimated light into six groups of light. The data acquisition system includes an acquisition card and a photoelectric sensor assembly, wherein the photoelectric sensor assembly includes five first photoelectric sensors composed of a filter assembly and a photomultiplier tube and a second photoelectric sensor composed of a filter assembly and an avalanche photodiode, and each of the six groups of light corresponds to a first photoelectric sensor or a second photoelectric sensor. The first photoelectric sensor and the second photoelectric sensor are electrically connected to the acquisition card, and the acquisition card is electrically connected to the industrial control computer; The laser emitted by the seed injection laser passes through a frequency doubling crystal module and a frequency tripling crystal module to be divided into three laser beams with wavelengths of 355nm, 532nm, and 1064nm, respectively; the beam expander group includes three beam expanders; the reflector group includes three reflector groups each consisting of two third reflectors, and each reflector group corresponds to a laser beam of one wavelength and one beam expander; The reflectivity of the reflection group to the laser of the corresponding wavelength is greater than 99%, and the threshold value is greater than 10J / cm 2 ; The seed injection laser is a laser with a single pulse energy greater than 100 mJ, the beam expander has a beam expansion multiple greater than 5 times, and a light transmission efficiency ≥ 95%; The subsequent optical assembly includes a grating, a first reflector and a collimating lens. The grating filters the light received by the telescope and then reflects the light through the first reflector to the collimating lens for collimation. The beam splitter assembly comprises a first beam splitter, a second beam splitter, a third beam splitter, a fourth beam splitter, a polarizing prism and a second reflector. The first beam splitter splits the light from the subsequent optical assembly into a first light path and a second light path. The second light path reaches the second beam splitter and is split into a third light path and a fourth light path. The third light path and the fourth light path enter two first photoelectric sensors respectively. The first light path reaches the third beam splitter and is split into a fifth light path and a sixth light path. The fifth light path enters a second photoelectric sensor. The sixth light path reaches the third beam splitter and is split into a seventh light path and an eighth light path. The seventh light path enters a first photoelectric sensor. The eighth light path reaches the fourth beam splitter and is split into a ninth light path and a tenth light path. The ninth light path enters a first photoelectric sensor. The tenth light path reaches the second reflector and is reflected to a first photoelectric sensor. The reflectivity of the first beam splitter to 660nm light is greater than 90%, and the transmittance to 607nm light is greater than 95%; the reflectivity of the second beam splitter to 660nm light is greater than 95%; the transmittance of the third beam splitter to 607nm light is greater than 95%, and the reflectivity to 1064nm light is greater than 90%; the reflectivity of the fourth beam splitter to 607nm light is greater than 95%, and the transmittance to 532nm light is greater than 95%; the polarizing prism is a 532nm polarizing beam splitter; The optical channel of the first photoelectric sensor corresponding to the third light is the 355nm signal channel, the optical channel of the first photoelectric sensor corresponding to the fourth light is the 660nm channel, the optical channel of the second photoelectric sensor corresponding to the fifth light is the 1064nm channel, the optical channel of the first photoelectric sensor corresponding to the seventh light is the 608nm channel, the optical channel of the first photoelectric sensor corresponding to the ninth light is the 532nm-S channel, and the optical channel of the first photoelectric sensor corresponding to the tenth light is the 532nm-P channel.

2. A three-wavelength multi-channel laser radar system according to claim 1, characterized in that: The telescope has an aperture of not less than 16 inches.

3. A three-wavelength multi-channel laser radar system according to claim 1, characterized in that: The seed injection laser also includes an energy monitoring module and a frequency monitoring module, and the energy monitoring module and the frequency monitoring module are electrically connected to the industrial control machine.

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