CN116931003A - Coherent laser wind-finding radar device - Google Patents

Abstract

The application provides a coherent laser wind-finding radar device, comprising: the system comprises a laser light source module, a signal receiving and transmitting module and a signal receiving and processing module, wherein the laser light source module is used for generating a multi-wavelength laser detection signal and a multi-wavelength local oscillation signal, the multi-wavelength laser detection signal is transmitted to the signal receiving and transmitting module, and the multi-wavelength local oscillation signal is transmitted to the signal receiving and processing module; the signal receiving and transmitting module is used for transmitting the multi-wavelength laser detection signals generated by the laser light source module into the atmosphere and receiving echo signals scattered back by atmospheric aerosol particles after the multi-wavelength laser detection signals are emitted into the atmosphere, wherein the echo signals carry wind speed information; and the signal receiving and processing module is used for performing beat frequency processing on the echo signals according to the multi-wavelength local oscillation signals to generate a plurality of frequency shift signals, and obtaining wind speed information based on the plurality of frequency shift signals. The coherent laser wind-finding radar device can improve the output power of laser signals in the laser radar by emitting the multi-wavelength laser detection signals, thereby improving the detection performance of the laser radar.

Description

Coherent laser wind-finding radar device

Technical Field

The application relates to the field of radars, in particular to a coherent laser wind-finding radar device.

Background

Atmospheric wind field detection is an important component of the meteorological field, and wind has an important influence on human activities. In the field of aerospace, meteorological monitoring and forecasting are important factors for guaranteeing flight safety, the airspace wind field information is accurately and rapidly updated, and relevant data are reflected to pilots, so that the method is greatly helpful for flight safety; in the field of wind power generation, in order to develop wind energy more efficiently and safely, real-time wind field detection data is required to control the operating state of wind power generation equipment; in the military field, wind field detection can provide important guarantee for safe use and accurate striking of ground-air, air-air and air-ground weapons, and meteorological guarantee of personnel and equipment parachuting, gun shooting and other military operations also needs to be realized through atmospheric wind field detection; in the meteorological field, through accurate atmospheric wind field information, future weather can be predicted more accurately, especially the forecast of typhoon weather.

At present, the detection equipment for detecting the atmospheric wind field is mainly divided into a passive type and an active type according to the working mode. The traditional passive wind measuring equipment comprises an anemometer, a wind vane, a sonde and the like, and the active wind measuring equipment comprises a microwave wind measuring radar, a laser wind measuring radar and the like. The passive wind measuring equipment can only measure the local wind field information of the position of the detector, the obtained information quantity is small, if the wind field in the area range needs to be detected, relevant equipment needs to be installed in the detection area according to a certain density, and the total cost is high. The frequency band used by the microwave wind-finding radar only acts with large-size particles such as clouds, rain and snow to generate echo signals in the atmosphere, and the intensity of the echo signals generated by the microwave radar on atmospheric molecules and aerosol is very low under a clear sky condition to form a detection blind area, so that the detection performance of the microwave wind-finding radar is poor. The laser wind-finding radar generally uses infrared laser with shorter wavelength, realizes detection of wind signals by detecting scattering signals of atmospheric molecules and aerosol, has small detection performance affected by weather, and has high time and spatial resolution, thus becoming an important means for wind field measurement.

In the prior art, the laser wind-finding radar at least comprises a laser source and an optical fiber amplifying module, wherein the laser source is generally a single-wavelength laser. In the practical use process, when the optical fiber amplification module amplifies a single-wavelength laser signal, the nonlinear effect of the optical fiber amplification module is easy to occur due to the narrow linewidth of the single-wavelength laser signal, so that the output power of the single-wavelength laser signal in the laser can be limited, and the detection performance of the laser radar is greatly reduced. In addition, in the prior art, a scheme of coupling multiple sub-sources is also adopted, and the coherence performance is deteriorated due to the phase inconsistency among the multiple sub-sources, so that the synchronous phase locking technology is complex and is not easy to realize.

Disclosure of Invention

The application aims to overcome the defects in the prior art and provide a coherent laser wind-finding radar device which is used for improving the output power of a laser signal in a laser radar so as to improve the detection performance of the laser radar.

In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows:

the application provides a coherent laser wind-finding radar device, which comprises: a laser light source module, a signal receiving and transmitting module and a signal receiving and processing module,

the laser light source module is used for generating a multi-wavelength laser detection signal and a multi-wavelength local oscillation signal, wherein the multi-wavelength laser detection signal is transmitted to the signal receiving and transmitting module, and the multi-wavelength local oscillation signal is transmitted to the signal receiving and processing module;

the signal receiving and transmitting module is used for transmitting the multi-wavelength laser detection signals generated by the laser light source module into the atmosphere and receiving echo signals scattered back by atmospheric aerosol particles after the multi-wavelength laser detection signals are emitted into the atmosphere, wherein the echo signals carry wind speed information; and

the signal receiving and processing module is used for performing beat frequency processing on the echo signals according to the multi-wavelength local oscillation signals to generate a plurality of frequency shift signals, and obtaining wind speed information based on the plurality of frequency shift signals.

Further, the laser light source module comprises a seed source and a beam splitter, wherein the seed source is used for outputting a multi-wavelength laser signal and transmitting the multi-wavelength laser signal to the beam splitter, and the beam splitter is used for splitting the received multi-wavelength laser signal into the multi-wavelength laser detection signal and the multi-wavelength local oscillation signal.

Further, the laser light source module further includes an optical fiber amplifier for receiving the multi-wavelength laser detection signal output by the beam splitter and amplifying the multi-wavelength laser detection signal.

Further, the laser light source module further comprises a modulator, wherein the modulator is connected in series between the first output end of the beam splitter and the optical fiber amplifier, and is used for modulating the multi-wavelength laser detection signal output by the beam splitter before the multi-wavelength laser detection signal is transmitted to the optical fiber amplifier.

Further, the coherent laser wind-finding radar device further includes: the circulator comprises a first end, a second end and a third end, wherein the first end of the circulator is connected with the laser light source module, the second end of the circulator is connected with the signal receiving and transmitting module, and the third end of the circulator is connected with the signal receiving and processing module;

the multi-wavelength laser detection signal generated by the laser source module is input to the first end of the circulator and then output to the signal receiving and transmitting module through the second end, and the echo signal received by the signal receiving and transmitting module is input to the second end of the circulator and then output to the signal receiving and processing module through the third end.

Further, the signal receiving and transmitting module comprises a telescope system and a light beam scanning system which are sequentially arranged along the propagation direction of the multi-wavelength laser detection signal.

Further, the signal receiving and processing module comprises a signal coupler, a balance detector, a digital acquisition card and a signal processor which are connected in sequence, wherein

The first input end of the signal coupler is used for receiving the multi-wavelength local oscillation signal, the second input end of the signal coupler is used for receiving the echo signal, the output end of the signal coupler is connected with the balance detector,

the balance detector is used for performing beat frequency processing on the multi-wavelength local oscillation signals and the echo signals which are coupled by the signal coupler to generate a plurality of frequency shift signals, accumulating the plurality of frequency shift signals to output electric signals,

the acquisition card is used for acquiring the electric signals output by the balance detector and outputting the acquired electric signals to the signal processor, and

and the signal processor is used for carrying out wind speed inversion on the signal output by the acquisition card so as to obtain the wind speed information.

Further, the seed source is a multi-longitudinal mode laser.

Further, the seed source is an optical frequency comb.

The beneficial effects of the application are as follows: the coherent laser wind-finding radar device can improve the output power of laser signals in the laser radar by transmitting the multi-wavelength laser detection signals, thereby improving the signal-to-noise ratio of laser radar echo signals. In addition, due to the adoption of a single sub-source, the coherence deterioration caused by a plurality of sub-source coupling modes is avoided, and the detection performance of the laser radar is greatly improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic structural view of a coherent lidar device according to an embodiment of the present application;

FIG. 2 is a schematic view of a laser light source module in the coherent lidar device shown in FIG. 1;

FIG. 3 schematically illustrates a pulse waveform generated by an optical frequency comb;

FIG. 4 is a schematic view of still another configuration of a laser light source module in the coherent lidar device shown in FIG. 2;

FIG. 5 is a schematic diagram of the structure of the fiber amplifier in the laser light source module shown in FIG. 4;

FIG. 6 is a schematic view of still another configuration of a laser light source module in the coherent lidar device shown in FIG. 2;

FIG. 7 is a schematic diagram of a signal transceiver module in the coherent lidar device shown in FIG. 1;

FIG. 8 is a schematic diagram of a signal receiving and processing module in the coherent lidar device shown in FIG. 1;

fig. 9 is a schematic structural view of a coherent laser wind radar device according to still another embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Currently, the most widely used lidar is either a pulsed lidar or a continuous lidar based on the doppler coherent detection principle. In the prior art, a laser wind-finding radar generally uses single-frequency laser as a detection light source, heterodynes detection is carried out on a backscattering signal of detection light by using a local oscillation light signal and aerosol particles in the atmosphere, and a view-direction wind speed is calculated by detecting difference frequency information in a Doppler signal, so that wind field data is obtained by further inversion. However, in practical application, when the optical fiber amplification module amplifies a single-wavelength laser signal, due to the narrow linewidth of the single-wavelength laser signal, nonlinear effects of the optical fiber amplification module are easy to occur, and further the output power of the single-wavelength laser signal in the laser is limited, so that the detection performance of the laser radar is greatly reduced.

Based on the above problems, the present application provides a coherent laser wind-finding radar device to improve the output power of laser signals in a laser radar, thereby improving the detection performance of the laser radar.

Fig. 1 is a schematic structural view of a coherent lidar device according to an embodiment of the present application. As shown in fig. 1, the coherent laser wind lidar device 100 includes a laser light source module 11, a signal transmitting/receiving module 12, and a signal receiving/processing module 13.

The laser light source module 11 is used for generating a multi-wavelength laser detection signal and a multi-wavelength local oscillation signal. Wherein, the multi-wavelength laser detection signal is transmitted to the signal transceiver module 12, and the multi-wavelength local oscillation signal is transmitted to the signal receiving and processing module 13.

The signal transceiver module 12 is connected with the laser light source module 11, and is configured to receive the multi-wavelength laser detection signal generated by the laser light source module 11, transmit the multi-wavelength laser detection signal to the atmosphere, and receive an echo signal scattered back by the aerosol particles after the multi-wavelength laser detection signal is emitted to the atmosphere. Wherein the echo signal carries wind speed information. The echo signals are further transmitted to a signal receiving and processing module 13 via a signal transceiver module 12.

The signal receiving and processing module 13 is connected with the laser light source module 11 and the signal receiving and transmitting module 12. The signal receiving and processing module 13 has two input terminals, wherein a first input terminal is used for receiving the multi-wavelength local oscillation signal generated by the laser light source module 11, and a second input terminal is used for receiving the echo signal transmitted by the signal receiving and transmitting module 12. The signal receiving processing module 13 performs beat frequency processing on the echo signal according to the multi-wavelength local oscillation signal to generate a plurality of frequency shift signals, and obtains wind speed information based on the plurality of frequency shift signals.

Specifically, the signal receiving processing module 13 performs accumulation processing on the generated plurality of frequency shift signals, and performs wind speed inversion according to the accumulated plurality of frequency shift signals to obtain wind speed information.

Next, a specific structure of a laser light source module in the coherent laser wind radar apparatus according to an embodiment of the present application will be described.

Referring to fig. 2, there is shown an exemplary structural schematic diagram of a laser light source module in a coherent lidar device according to an embodiment of the present application. As shown in fig. 2, the laser light source module 11 includes a seed source 111 and a beam splitter 112. Specifically, the seed source 111 is connected to an input of the beam splitter 112, a first output of the beam splitter 112 is connected to the signal transceiver module 12, and a second output of the beam splitter 112 is connected to the signal receiving and processing module 13.

The seed source 111 employed in this embodiment is used to generate a plurality of laser signals of different wavelengths and transmit them to the beam splitter 112.

The beam splitter 112 is an optical device that splits a beam of light into two or more beams of light. The beam splitter 112 used in the present embodiment is a fiber splitter, which is used to split the multi-wavelength laser signal output by the seed source into two parts, wherein one part is used as a laser detection signal for detection and transmitted to the signal transceiver module 12, and the other part is used as a local oscillation signal for beat frequency processing with the echo signal and transmitted to the signal receiving and processing module 13.

Specifically, the seed source 111 employed in the present embodiment is a multi-wavelength laser, which can be implemented by a multi-longitudinal mode laser with uniform phase. The multi-longitudinal mode laser outputs a multi-longitudinal mode signal having a periodic repetition frequency interval, which corresponds to a plurality of wavelengths, respectively. It is noted that the inability to ensure phase consistency between the various sub-sources results in degraded coherence performance compared to using multiple sub-source coupling schemes. By adopting the scheme of the multi-longitudinal mode laser, a plurality of longitudinal modes in the multi-longitudinal mode laser are incoherent, and each longitudinal mode is coherent with the longitudinal mode, so that better coherence performance can be ensured.

In addition, the seed source 111 employed in the present embodiment may also be implemented by an optical frequency comb. An optical frequency comb is a spectrum that is spectrally composed of a series of frequency components that are uniformly spaced and have a coherent stable phase relationship. For example, the optical frequency comb may generate ultrashort optical pulses using a mode-locked laser, where the resulting adjacent pulse waves have identical time intervals, each pulse wave corresponding to a different wavelength, as shown in fig. 3, which schematically illustrates the pulse waveform output by the optical frequency comb. The foregoing is for illustrative purposes only and the optical frequency comb may also emit a continuous light source.

It should be noted that the multi-longitudinal mode laser and optical frequency comb described above are merely exemplary and that the seed source may be implemented by other suitable devices or means.

Further, on the basis of the foregoing embodiment, as shown in fig. 4, the laser light source module 11 further includes an optical fiber amplifier 113.

The optical fiber amplifier 113 is used for amplifying the multi-wavelength laser detection signal. The multi-wavelength laser detection signal for detection may be amplified or enhanced to achieve a desired output power before being emitted. Compared with the traditional semiconductor laser amplifier, the optical fiber amplifier does not need to carry out photoelectric conversion, electro-optical conversion, signal regeneration and other complex processes, can directly carry out all-optical amplification on signals, and can realize the full-optical amplification of the signals. Next, please refer to fig. 5, which is a schematic diagram illustrating a structure of an optical fiber amplifier in the coherent lidar device shown in fig. 4. As shown in fig. 5, the fiber amplifier 113 includes a pump source 1131, a coupler 1132, an optical fiber 1133, and a filter 1134. The pump source 1131 is configured to generate an excitation signal to excite the laser working substance. One input of the coupler 1132 is connected to the beam splitter 112 for receiving the multi-wavelength laser detection signal, and the other input of the coupler 1132 is connected to the pump source 32 for receiving the excitation signal. That is, the multi-wavelength laser detection signal is excited by an excitation signal generated by the pump source 1131. The output end of the coupler 1132 is connected to the input end of the optical fiber 31, and the output end of the optical fiber 31 is connected to the filter 33. The optical fiber 31 is an erbium-doped optical fiber or an erbium-ytterbium double-doped optical fiber, and the filter 33 is an optical filter or a bragg grating.

In this embodiment, in the process of amplifying the multi-wavelength laser detection signal by using the optical fiber amplifier 113, since the multi-wavelength laser detection signal has multiple frequency components, the spectrum is widened, so that the peak-to-peak power of the laser signal entering the optical fiber amplifier 113 is suppressed, the threshold of the brillouin scattering can be effectively improved, the gain of the optical fiber amplifier 113 is increased, and further, the output power of the multi-wavelength laser detection signal is obtained.

Further, on the basis of the foregoing embodiment, as shown in fig. 6, the laser light source module 11 further includes a modulator 114. A modulator 114 is connected in series between the first output of the beam splitter 112 and the fiber amplifier 113.

The modulator 114 may be used to modulate the multi-wavelength laser detection signal by modulating the electrical signal. In one possible implementation, it may refer to modulating the amplitude of the laser detection signal by modulating the electrical signal. In one possible implementation, the modulator may be an external modulator, that is, the modulation mode of the laser detection signal in the present application is external modulation. The external modulation refers to loading a modulation electric signal after the laser beam is formed, so that certain physical characteristics (such as amplitude, frequency and phase) of the modulator are correspondingly changed, and certain parameters of the laser detection signal are modulated when the laser detection signal passes through, thereby realizing amplitude modulation, frequency modulation, phase modulation, intensity modulation, pulse modulation and the like.

In the present application, the modulator may be an acousto-optic modulator or an electro-optic modulator. An acousto-optic modulator is generally referred to herein as an acousto-optic device that controls the variation in intensity of a laser beam. The acousto-optic modulation is an external modulation technology, and the modulation signal acts on the electroacoustic transducer in the form of electric signal (amplitude modulation) and then is converted into an ultrasonic field changing in the form of electric signal, when the optical wave passes through the acousto-optic medium, the optical carrier wave is modulated to become an intensity modulation wave carrying information due to the acousto-optic effect. Electro-optic modulators refer to modulators made using the electro-optic effect of certain electro-optic crystals, such as lithium niobate crystals (LiNb 03), gallium arsenide crystals (GaAs), and lithium tantalate crystals (LiTa 03). The electro-optic effect is that when a voltage is applied to the electro-optic crystal, the refractive index of the electro-optic crystal will change, resulting in a change in the characteristics of the light wave passing through the crystal, effecting modulation of the phase, amplitude, intensity, frequency and polarization state of the laser detection signal.

In the embodiment of the application, after the detection signal is modulated by the modulator, the detection signal can carry direction information so as to distinguish the positive and negative of the wind speed.

Whether or not the modulator is set depends on the setting of the system. The modulator may not be necessary if only the magnitude of the wind speed is to be detected and not the direction thereof. Furthermore, in the case of using a frequency modulation scheme to identify the direction of wind, there is no need to provide a modulator.

Referring next to fig. 7, a schematic structural diagram of a signal transceiver module in the coherent laser wind radar apparatus shown in fig. 1 is shown. As shown in fig. 7, the signal transceiver module 12 includes a telescope system 121 and an optical beam scanning system 122 disposed in order along the propagation direction of the multi-wavelength laser detection signal, wherein the telescope system includes an eyepiece and an objective lens.

The telescope system 121 can be a transmitting and receiving coaxial telescope system, and the focal length of the telescope system 121 can be adjusted. The beam scanning system 122 may be one of a wedge mirror, a scanner, and a multi-way optical switch, which is used to change the direction of the beam.

The multi-wavelength laser detection signal generated by the laser light source module 11 is output to an eyepiece of the telescope system 121, and an objective lens is expanded and collimated and then emitted to the atmosphere through the light beam scanning system 122; the echo signals scattered by the aerosol particles are received by the beam scanning system 122 and then enter the telescope system 121, and then output to the signal receiving and processing module 13.

Referring next to fig. 8, a schematic diagram of the structure of a signal receiving processing module in the coherent lidar device shown in fig. 1 is shown. As shown in fig. 8, the signal receiving processing module 13 includes a signal coupler 131, a balance detector 132, a digital acquisition card 133, and a signal processor 134, which are sequentially connected.

The signal coupler 131 is configured to couple the multi-wavelength local oscillation signal and the echo signal and output the coupled signals to the balance detector 132. The signal coupler 131 includes a first input end, a second input end and an output end, the first input end of the signal coupler 131 is connected with the second output end of the beam splitter 112 to receive the multi-wavelength local oscillator signal, the second input end of the signal coupler 131 is connected with the signal transceiver module 12 to receive the echo signal, and the output end of the signal coupler 131 is connected with the balance detector 132 to send the coupled multi-wavelength local oscillator signal and the echo signal to the balance detector 132. In the present embodiment, the signal coupler 131 is an optical fiber coupler. In other embodiments, other forms of couplers may be used, such as directional couplers, power splitters, and any of a variety of microwave branching devices, the application is not particularly limited.

The balance detector 132 is configured to perform beat frequency processing on the multi-wavelength local oscillation signal and the echo signal coupled by the signal coupler 131, generate a plurality of frequency shift signals related to wind field information, and further accumulate the plurality of frequency shift signals and output the accumulated frequency shift signals. The balance detector 132 receives two optical signals, and outputs an electrical signal.

The digital acquisition card 133 acquires the electric signal output by the balance detector 132, that is, the accumulated frequency shift signal, and outputs the acquired signal to the signal processor 134.

The signal processor 134 processes the collected accumulated frequency shifted signals, specifically, performs wind speed inversion on the accumulated frequency shifted signals by the signal processor 134 to obtain wind speed information. The signal processor 134 used in the present embodiment may be one of an industrial personal computer or an embedded platform. Of course, in other embodiments, signal processors of a model and type may be used, without further limitation.

The structure of the signal receiving processing module described above is merely exemplary, and it may be implemented by other suitable means, which is not specifically limited herein.

Further, based on the foregoing embodiment, as shown in fig. 9, the coherent lidar device 100 further includes a circulator 14. The circulator is also called an isolator and is characterized by unidirectional transmission of high-frequency signal energy. The electromagnetic wave is controlled to transmit along a certain annular direction, and the characteristic of unidirectional transmission of high-frequency signal energy is mainly used between the output end of the high-frequency power amplifier and a load, and the electromagnetic wave has the functions of independent and mutual isolation.

As shown in fig. 9, the circulator 14 includes a first end, a second end and a third end, the first end of the circulator 14 is connected to the output end of the laser light source module 11, the second end is connected to the signal transceiver module 12, and the third end is connected to the second input end of the signal receiving and processing module 13. The multi-wavelength laser detection signal generated by the laser light source module 11 is input to a first end of the circulator 14 and then output to the signal receiving and transmitting module 12 from a second end, and the echo signal received by the signal receiving and transmitting module 12 is input to a second end of the circulator 14 and then output to the signal receiving and processing module 13 from a third end.

The operation principle of the laser wind-finding radar apparatus 100 is briefly described below in an exemplary manner, specifically as follows:

the seed source 111 generates a multi-wavelength laser signal, the beam splitter 112 divides the multi-wavelength laser signal into two parts, one part is input to the signal transceiver module 12 for laser detection, and the other part is input to the signal receiving and processing module 13 for subsequent beat frequency processing.

The multi-wavelength laser detection signals enter the signal receiving and transmitting module 12, the signal receiving and transmitting module 12 transmits the multi-wavelength laser detection signals to the atmosphere, aerosol particles moving in the atmosphere collide with the multi-wavelength laser detection signals to generate echo signals carrying wind speed information, and the echo signals are continuously received by the signal receiving and transmitting module 12 and then transmitted to the signal coupler 131 in the signal receiving and processing module 13. Wherein the echo signal comprises a plurality of frequency shift signals with different frequency components.

The signal coupler 131 couples the multi-wavelength local oscillation signal and the echo signal and outputs the coupled signals to the balance detector 132, the balance detector 132 performs beat frequency processing on the multi-wavelength local oscillation signal and the echo signal, generates a plurality of frequency shift signals related to wind field information, then performs accumulation processing on the plurality of frequency shift signals and transmits the accumulated frequency shift signals to the digital acquisition card 133 and the signal processor 134, and the signal processor 134 obtains a speed value of the radial wind speed after signal processing according to a corresponding relation between the accumulated frequency shift signals and the speed value of the radial wind speed.

In the balance detector 132, since multi-wavelength detection is adopted, the frequency shift signals generated by each wavelength are accumulated after being subjected to beat frequency, so that the signal-to-noise ratio of the echo signals can be effectively improved, and the detection performance of the laser radar is further improved.

The coherent laser wind-finding radar device provided by the application has the following beneficial effects. The coherent laser wind-finding radar device can improve the output power of laser signals in the laser radar by transmitting the multi-wavelength laser detection signals, thereby improving the signal-to-noise ratio of laser radar echo signals. In addition, due to the adoption of a single sub-source, the coherence deterioration caused by a plurality of sub-source coupling modes is avoided, and the detection performance of the laser radar is greatly improved.

It should be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (9)

1. A coherent laser wind-finding radar apparatus, comprising: a laser light source module, a signal receiving and transmitting module and a signal receiving and processing module,

the laser light source module is used for generating a multi-wavelength laser detection signal and a multi-wavelength local oscillation signal, wherein the multi-wavelength laser detection signal is transmitted to the signal receiving and transmitting module, and the multi-wavelength local oscillation signal is transmitted to the signal receiving and processing module;

the signal receiving and transmitting module is used for transmitting the multi-wavelength laser detection signals generated by the laser light source module into the atmosphere and receiving echo signals scattered back by atmospheric aerosol particles after the multi-wavelength laser detection signals are emitted into the atmosphere, wherein the echo signals carry wind speed information; and

the signal receiving and processing module is used for performing beat frequency processing on the echo signals according to the multi-wavelength local oscillation signals to generate a plurality of frequency shift signals, and obtaining wind speed information based on the plurality of frequency shift signals.

2. A coherent laser wind radar apparatus according to claim 1, wherein said laser light source module comprises a seed source for outputting a multi-wavelength laser signal and transmitting to said beam splitter for splitting the received multi-wavelength laser signal into said multi-wavelength laser detection signal and said multi-wavelength local oscillator signal.

3. A coherent laser wind lidar device according to any of claims 2 to, wherein the laser light source module further comprises an optical fiber amplifier for receiving the multi-wavelength laser detection signal outputted from the beam splitter and amplifying the multi-wavelength laser detection signal.

4. A coherent lidar device according to claim 3, wherein the laser light source module further comprises a modulator connected in series between the first output end of the beam splitter and the optical fiber amplifier for modulating the multi-wavelength laser detection signal output by the beam splitter before the multi-wavelength laser detection signal is transmitted to the optical fiber amplifier.

5. A coherent lidar device according to claim 1, further comprising:

the circulator comprises a first end, a second end and a third end, wherein the first end of the circulator is connected with the laser light source module, the second end of the circulator is connected with the signal receiving and transmitting module, and the third end of the circulator is connected with the signal receiving and processing module;

the multi-wavelength laser detection signal generated by the laser source module is input to the first end of the circulator and then output to the signal receiving and transmitting module through the second end, and the echo signal received by the signal receiving and transmitting module is input to the second end of the circulator and then output to the signal receiving and processing module through the third end.

6. A coherent laser wind radar apparatus according to claim 1, wherein said signal transceiver module comprises a telescope system and a beam scanning system arranged in sequence along the propagation direction of said multi-wavelength laser probe signal.

7. The coherent lidar device according to claim 1, wherein the signal receiving and processing module comprises a signal coupler, a balance detector, a digital acquisition card and a signal processor connected in sequence, wherein

The first input end of the signal coupler is used for receiving the multi-wavelength local oscillation signal, the second input end of the signal coupler is used for receiving the echo signal, the output end of the signal coupler is connected with the balance detector,

the balance detector is used for performing beat frequency processing on the multi-wavelength local oscillation signals and the echo signals which are coupled by the signal coupler to generate a plurality of frequency shift signals, accumulating the plurality of frequency shift signals to output electric signals,

the acquisition card is used for acquiring the electric signals output by the balance detector and outputting the acquired electric signals to the signal processor, and

and the signal processor is used for carrying out wind speed inversion on the signal output by the acquisition card so as to obtain the wind speed information.

8. A coherent laser wind lidar device according to any of claims 1 to 7, wherein the seed source is a multi-longitudinal mode laser.

9. A coherent laser wind radar apparatus according to any one of claims 1 to 7, wherein the seed source is an optical frequency comb.