WO2020199447A1

WO2020199447A1 - Broad-spectrum light source-based wind measurement lidar

Info

Publication number: WO2020199447A1
Application number: PCT/CN2019/099781
Authority: WO
Inventors: 上官明佳; 夏海云; 薛向辉; 窦贤康
Original assignee: 中国科学技术大学
Priority date: 2019-03-29
Filing date: 2019-08-08
Publication date: 2020-10-08
Also published as: CN109959944A; CN109959944B

Abstract

A broad-spectrum light source-based wind measurement lidar, wherein optical switches (24, 25) are used for gating so that emitted laser light and an atmospheric echo signal share one filter (21), thereby achieving the direct detection of the broad-spectrum light source-based wind measurement lidar; a frequency shifter (31) is used to shift the frequency of the emitted laser light onto the edge of the filter (21); and when the Doppler frequency shift of the atmospheric echo signal occurs, the intensity of a transmitted signal and a reflected signal of the atmospheric echo signal traversing the filter (21) will change, wherein one increases and one decreases, and the atmospheric wind speed is extracted by means of intensity change information. Since the emitted laser light and the atmospheric echo signal traverse the filter (21) within a time in the order of milliseconds or even microseconds, the present wind measurement lidar has the following advantages: first, the wind measurement lidar is not sensitive to the frequency drift of the laser and the filter (21); secondly, there is no need to use a narrow line width single-frequency laser, and the broad-spectrum light source may increase exit laser power and reduce the cost of the laser; and finally, no reference laser is needed, which simplifies the optical path.

Description

Wind Lidar Based on Broad Spectrum Light Source

This application claims the priority of the Chinese patent application CN201910256086.7 filed on March 29, 2019, the content of which is incorporated herein by reference.

Technical field

The invention relates to the field of laser radar, in particular to a direct detection wind measurement laser radar based on a broad-spectrum light source.

Background technique

In the remote sensing of atmospheric wind speed, the wind lidar has been widely used in atmospheric wind profile detection, wind shear early warning, aircraft wake detection, wind power generation, aerospace, military and other fields due to its high precision and high temporal and spatial resolution. .

Wind lidar can be divided into direct detection and coherent detection. At present, the light sources of the wind lidars of these two mechanisms use demanding narrow linewidth lasers. Coherent lidar uses a narrow line width to increase the coherence length, thereby improving the coherence efficiency. The wider the spectrum, the worse the coherence efficiency. In the direct detection wind lidar, by using a narrow linewidth laser to lock on the steep edge of the filter, the weak Doppler frequency shift will cause a large change in the transmission intensity, so as to extract the wind speed information. The narrower detection sensitivity is higher. In practical applications, due to the drift between the laser and the filter, a reference light needs to be used to lock the laser frequency on the filter. This brings about the following problems. First of all, when the surrounding temperature and pressure change greatly, it will cause a large frequency drift of the laser and filter, which increases the difficulty of locking and also raises the stability of the system. Better requirements, on the other hand, introduce systematic errors; secondly, in fiber lasers, the narrower the line width, the stronger the stimulated Brillouin scattering effect, which limits the output power of the laser and increases the cost of the laser .

Summary of the invention

One aspect of the present disclosure provides a wind measurement lidar based on a broad-spectrum light source, which includes: a seed laser pulse generation unit for generating seed laser pulses; a filter unit, including a filter, which is used for The pulse is filtered; the laser frequency shifting and amplifying unit is used to receive the filtered seed laser pulse filtered by the filtering unit, and to frequency shift and amplify the filtered seed laser pulse; the laser transmitting and receiving unit uses For receiving the frequency-shifted and amplified laser light that has been frequency-shifted and amplified by the laser frequency shifting and amplifying unit, and emitting the frequency-shifted and amplified laser into the atmosphere; the laser emitting and receiving unit also uses After receiving the atmospheric echo signal generated after the frequency-shifted and amplified seed laser pulse interacts with the atmosphere; wherein, after the atmospheric echo signal received by the laser transmitting and receiving unit is filtered by the filter, The transmission signal and the reflection signal are obtained respectively, and these two signals are sensitive to the atmospheric Doppler frequency shift, and atmospheric wind speed information can be obtained by inversion by measuring the intensity change of the transmission signal and the reflection signal.

Optionally, the above-mentioned wind measurement lidar based on a broad-spectrum light source further includes: an echo signal detection unit for detecting the transmission signal and the reflection signal; a signal acquisition and processing unit for collecting the echo signal The transmission signal and the reflection signal detected by the detection unit, and the intensity change of the transmission signal and the reflection signal are measured, and the atmospheric wind speed information is obtained by inversion.

Optionally, in the above-mentioned wind measurement lidar based on a broad-spectrum light source, the filtering unit further includes: a first optical switch and a second optical switch. In a gating manner, the seed laser pulse and the atmospheric echo signal pass through the filter in time sharing, wherein the first optical switch is connected to the seed laser pulse generating unit, and the second optical switch is connected to the filter. The laser frequency shift and amplification unit and the echo signal detection unit are connected.

Optionally, the above-mentioned wind measurement lidar based on a broad-spectrum light source, wherein the seed laser pulse is incident on the filter after passing through the first optical channel of the first optical switch, and the filter is The seed laser pulse is filtered to obtain the filtered seed laser pulse, and the filtered seed laser pulse is incident on the first optical channel of the second optical switch, and then input to the laser frequency shift and amplification unit.

Optionally, the aforementioned filtering unit further includes: a circulator connected to the laser emitting and receiving unit and the echo signal detection unit, wherein the atmospheric echo signal received by the laser emitting and receiving unit passes through After the circulator, the second optical channel passing through the first optical switch enters the filter, and after filtering by the filter, a transmission signal and a reflection signal are obtained respectively; the transmission signal passes through the second light After the second optical channel of the switch enters the echo signal detection unit; the reflected signal enters the echo signal detection unit after passing through the second optical channel of the first optical switch and the circulator.

Optionally, the above-mentioned seed laser pulse generating unit includes: a seed laser for generating a seed laser; a pulse generator connected to the seed laser for receiving the seed laser and generating pulsed laser based on the seed laser; The first filter is connected to the pulse generator and filters the pulse laser to form the seed laser pulse.

Optionally, the aforementioned filter includes a second filter and a third filter, and the second filter is connected to the third filter.

Optionally, the above-mentioned laser frequency shift and amplification unit includes: a laser frequency shifter, connected to the filter unit, for receiving the filtered seed laser pulse from the filtering unit, and performing processing on the filtered seed laser pulse Frequency shift; Delay fiber, connected to the laser frequency shifter, used to receive the frequency-shifted seed laser pulse from the laser frequency shifter, and delay the frequency-shifted seed laser pulse, so that the atmosphere returns The wave signal is separated from the seed laser pulse in the time domain; an optical fiber amplifier is connected to the delay fiber and the laser transmitting and receiving unit for receiving the delayed seed laser pulse from the delay fiber, and The delayed seed laser pulse is amplified to obtain the frequency-shifted and amplified seed laser pulse, and the frequency-shifted and amplified seed laser pulse is input to the laser emitting and receiving unit.

Optionally, the above-mentioned signal collection and processing unit includes: a collection card for collecting the transmission signal and the reflection signal detected by the echo signal detection unit; a processor for measuring the collection card The intensity changes of the transmitted signal and the reflected signal are inverted to obtain atmospheric wind speed information.

Optionally, the above-mentioned laser transmitting and receiving unit includes: a transmitting telescope for transmitting the frequency-shifted and amplified seed laser pulse from the laser frequency shifting and amplifying unit into the atmosphere; and a receiving telescope for receiving The atmospheric echo signal of the atmosphere, and the atmospheric echo signal is input to the filtering unit.

The direct detection wind lidar proposed in the present disclosure adopts an optical switch gating method to achieve a broad-spectrum light source of the echo signal, and the seed laser pulse is locked at the half height of the filter through the frequency shift of the laser frequency shifter. So as to realize the detection of atmospheric wind field. The wind measurement lidar proposed in the publication has the characteristics of high system stability, no reference light, insensitive to laser frequency jitter, and high output power of broad-spectrum laser.

Description of the drawings

In order to explain the technical solutions of the embodiments of the present disclosure more clearly, the following will briefly introduce the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only the embodiments of the present disclosure. For those of ordinary skill in the field, without creative work, other drawings can be obtained from these drawings. For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description in conjunction with the accompanying drawings, in which:

Fig. 1 schematically shows a schematic diagram of an optical path of a lidar according to an embodiment of the present disclosure;

Fig. 2 schematically shows a working sequence diagram of a lidar according to an embodiment of the present disclosure; and

Fig. 3 schematically shows a schematic diagram of the principle of direct detection wind measurement of lidar according to an embodiment of the present disclosure.

detailed description

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concept of the present disclosure.

The terms used here are only for describing specific embodiments, and are not intended to limit the present disclosure. The terms "including", "including", etc. used herein indicate the existence of the described features, steps, operations and/or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having meanings consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

In the case of using an expression similar to "at least one of A, B, C, etc.", generally speaking, it should be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "having A, B and C" At least one of the "systems" shall include but not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and/or systems having A, B, C, etc. ). In the case of using an expression similar to "at least one of A, B or C, etc.", generally speaking, it should be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "having A, B or C" At least one of the "systems" shall include but not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and/or systems having A, B, C, etc. ).

The following describes the technical solutions in the embodiments of the present disclosure clearly and completely with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

Fig. 1 schematically shows a schematic diagram of an optical path of a lidar according to an embodiment of the present disclosure.

As shown in FIG. 1, the lidar of the embodiment of the present disclosure, particularly a direct detection wind measurement lidar based on a broad-spectrum light source, includes a seed laser pulse generating unit 10, a filtering unit 20, a laser frequency shifting and amplifying unit 30, The laser emitting and receiving unit 40, the echo signal detecting unit 50, and the signal collecting and processing unit 60.

According to an embodiment of the present disclosure, the seed laser pulse generating unit 10 is used to generate seed laser pulses. Alternatively, the seed laser pulse generating unit 10 may also be another laser capable of generating broad-spectrum laser pulses.

According to an embodiment of the present disclosure, the seed laser pulse generating unit 10 includes, for example, a seed laser 11, a pulse generator 12, and a first filter 13. Among them, the seed laser 11 includes, for example, a continuous broad-spectrum seed laser for generating seed laser light. The pulse generator 12 is connected to the seed laser 11 for receiving the seed laser and generating pulse laser based on the seed laser. The first filter 13 is connected to the pulse generator 12 and filters the pulsed laser light to form a seed laser pulse, and the seed laser pulse is incident on the filter unit 20.

Specifically, the seed laser 11 first passes through the pulse generator 12 to form pulsed light, and then passes through the first filter 13 to intercept the spectrum for detection. The preferred laser has a center wavelength of 1.5 microns.

According to an embodiment of the present disclosure, the filtering unit 20 includes a filter 21 for filtering the generated seed laser pulse.

According to the embodiment of the present disclosure, the filtering unit 20 further includes: a first optical switch 24 and a second optical switch 25, and the seed laser pulse and the atmospheric echo signal are separated by the gating manner of the first optical switch 24 and the second optical switch 25 When passing through the filter 21, the first optical switch 24 is connected to the seed laser pulse generating unit 10, and the second optical switch 25 is connected to the laser frequency shift and amplification unit 30 and the echo signal detection unit 50.

According to the embodiment of the present disclosure, after the seed laser pulse passes through the first optical channel of the first optical switch 24, it is incident on the filter 21, and the filter 21 filters the seed laser pulse to obtain a filtered seed laser pulse. The first optical channel incident to the second optical switch 25 is further input to the laser frequency shift and amplification unit 30.

In the embodiment of the present disclosure, the filter 21 includes a second filter 22 and a third filter 23, and the second filter 22 and the third filter 23 are connected.

Specifically, the seed laser pulse passes through the first optical channel of the first optical switch 24 (for example, channels 1-2 of the first optical switch 24), enters the second filter 22, and then passes through the third filter 23 and the first optical channel. The first optical channel of the second optical switch 25 (for example, the 1-2 channels of the second optical switch 25). Among them, the first optical switch 24 and the second optical switch 25 are used to gate the seed laser pulse and the atmospheric echo signal. The second filter 22 is used to filter the atmospheric echo information and filter out the sun background and sky background radiation. The third filter 23 is used to filter out seed laser pulses and as an edge filter for atmospheric wind field detection.

According to an embodiment of the present disclosure, the laser frequency shifting and amplifying unit 30 is configured to receive the laser light filtered by the filter unit 20, and perform frequency shift and amplify the filtered laser light. The laser frequency shift and amplification unit 30 includes: a laser frequency shifter 31, a delay fiber 32, and a fiber amplifier 33.

The laser frequency shifter 31 is connected to the filter unit 20, and is used to receive the filtered laser light from the filter unit 20 and perform frequency shift on the filtered laser light. The delay fiber 32 is connected to the laser frequency shifter 31, and is used to receive the frequency-shifted laser light from the laser frequency shifter 31 and delay the frequency-shifted laser light, so that the atmospheric echo signal and the seed laser light The pulses are separated in the time domain. The fiber amplifier 33 is connected to the delay fiber 32 and the laser transmitting and receiving unit 40, and is used to receive the delayed laser light from the delay fiber 32, and amplify the delayed laser to obtain the frequency shifted and amplified laser, and the The frequency shifted and amplified laser light is input to the laser emitting and receiving unit 40.

Among them, the laser light emitted by the filter unit 20 first passes through the laser frequency shifter 31, and then passes through the delay fiber 32 and the fiber amplifier 33 for delay and optical amplification. The laser frequency shifter 31 is used to move the laser light emitted from the filter unit 20 to the half height of the transmittance curve of the third filter 23. The delay fiber 32 is used to separate the outgoing laser pulse and the atmospheric echo signal in the time domain.

According to an embodiment of the present disclosure, the laser transmitting and receiving unit 40 is used to receive the frequency-shifted and amplified laser light that has been frequency-shifted and amplified by the laser frequency-shifting and amplifying unit 30, and emits the frequency-shifted and amplified laser into the atmosphere, The laser emitting and receiving unit 40 is also used to receive the atmospheric echo signal generated after the frequency-shifted and amplified laser interacts with the atmosphere.

Among them, the atmospheric echo signal received by the laser transmitting and receiving unit 40 is filtered by the filter 21 to obtain a transmission signal and a reflection signal, respectively. These two signals are sensitive to the atmospheric Doppler frequency shift, and the transmission signal and the reflection signal are measured. The intensity change of can be inverted to obtain atmospheric wind speed information.

Specifically, the laser transmitting and receiving unit 40 includes: a transmitting telescope 41 and a receiving telescope 42. The transmitting telescope 41 is used to emit the frequency shifted and amplified laser light from the laser frequency shift and amplification unit 30 into the atmosphere. The receiving telescope 42 is used for receiving atmospheric echo signals from the atmosphere, and inputting the atmospheric echo signals into the filtering unit 20.

According to the embodiment of the present disclosure, the laser transmitting and receiving unit 40 transmits the amplified laser pulses into the atmosphere through the transmitting telescope 41, and the atmospheric echo signal generated by the interaction of the laser pulses with the atmosphere is received by the receiving telescope 42. As shown in Fig. 1, the laser transmission and atmospheric echo signal reception are separate transmission and reception structures, which is a preferred solution. It can also be a coaxial transmission and reception structure, and a telescope is shared for transmission and reception.

According to the embodiment of the present disclosure, the filtering unit 20 further includes a circulator 26 connected to the laser emitting and receiving unit 40 and the echo signal detecting unit 50.

Among them, the atmospheric echo signal received by the laser transmitting and receiving unit 40 passes through the circulator 26, passes through the second optical channel of the first optical switch 24, enters the filter 21, and is filtered by the filter 21 to obtain the transmission signal and the reflection signal respectively. The transmitted signal enters the echo signal detection unit 50 after passing through the second optical channel of the second optical switch 25, and the reflected signal enters the echo signal detection unit after passing through the second optical channel of the first optical switch 24 and the circulator 26 50.

For example, after the atmospheric echo signal passes through the circulator 26, it enters the second filter 22 and the third filter 23 through the second optical channel of the first optical switch 24 (for example, the 3-2 channel of the first optical switch 24). , Wherein the transmission signal enters the echo signal detection unit 50 through the second optical channel of the second optical switch 25 (for example, channels 1-4 of the second optical switch 25). The atmospheric echo signal passes through the reflected signal of the third filter 23, passes through the second filter 22 and then the second optical channel of the first optical switch 24 (for example, channels 2-3 of the first optical switch 24), and then enters the return signal. Wave signal detection unit 50.

According to an embodiment of the present disclosure, the echo signal detection unit 50 is used to detect the transmission signal and the reflection signal.

Among them, the echo signal detection unit 50 is a single photon detector, which includes but is not limited to a superconducting nanowire single photon detector, a frequency up-conversion single photon detector, and an InGaAs (indium gallium arsenide) single photon detector.

Specifically, when the echo signal detection unit 50 is a superconducting nanowire single photon detector, it may include a refrigerated preparation and superconducting chip 51, an electric pulse signal amplification unit 52, and an electric pulse signal discrimination unit 53. Among them, the refrigeration preparation and superconducting chip 51 is used to convert a single photon signal into an electrical pulse signal, the electrical pulse signal amplifying unit 52 is used to amplify the electrical pulse signal, and the electrical pulse signal discriminating unit 53 is used to discriminate electricity that exceeds a certain threshold. Pulse signal.

According to the embodiment of the present disclosure, the signal acquisition and processing unit 60 is used to collect the transmission signal and the reflection signal detected by the echo signal detection unit 50, measure the intensity changes of the transmission signal and the reflection signal, and obtain atmospheric wind speed information by inversion.

Specifically, the signal collection and processing unit 60 includes: a collection card 61 and a processor 62. The acquisition card 61 is used to acquire the transmission signal and the reflection signal detected by the echo signal detection unit 50. The processor 62 (for example, a computer) is used to measure the signal intensity of the transmission signal and the reflection signal collected by the acquisition card 61, and retrieve the atmospheric wind speed information.

Fig. 2 schematically shows a working sequence diagram of a lidar according to an embodiment of the present disclosure.

As shown in Figure 2, the gating of the seed laser pulse and the atmospheric echo signal is completed by the first optical switch 24 and the second optical switch 25, that is, the pulsed laser line passes through the 1-2 channels of the first optical switch 24 and the second optical switch 24. The 1-2 channels of the optical switch 25 are incident into the atmosphere, and then the level of the electrical signal input to the optical switch is adjusted so that the 1-2 channels of the first optical switch 24 and the 1-2 channels of the second optical switch 25 are closed , And then turn on channels 3-2 of the first optical switch 24 and channels 1-4 of the second optical switch 25 to complete the filtering of atmospheric echo signals. The laser frequency shifter 31 moves the seed laser pulse frequency to the half height of the transmittance curve of the third filter 23. Through signal collection, the transmission signal and the reflection signal of the atmospheric echo signal through the third filter 23 are obtained respectively, as shown in FIG. 2.

As shown in Figure 3, since the emitted laser and echo signal share a filter, the Fabry-Perot interferometer (FPI) spectrum and the laser spectrum have the same linear shape. The type is the Lorentz line, the convolution of the two Lorentz functions is still the Lorentz line, and the width is the sum of the widths of the two Lorentz functions. Therefore, the convolution of the atmospheric echo signal and the Fabry-Perot interferometer is still a Lorentz line, but the width is doubled. The atmospheric echo signal is transmitted through the transmission spectrum of the Fabry-Perot interferometer. And the reflection spectrum is shown in Figure 3(b). By using a laser frequency shifter (AOM) to frequency shift the emitted laser frequency, for example, the laser frequency is locked at the half height of the curve shown in Figure 3(b).

The core module of the present disclosure is the filter module 20. The first optical switch 24 and the second optical switch 25 are gated to realize that the emitted laser and the atmospheric echo signal pass through the same filter 21, thereby realizing a broad-spectrum light source. In order to extract the frequency shift of the atmospheric echo signal and realize the detection of the atmospheric wind field, the emitted laser is frequency shifted to the edge of the filter 21 by the laser frequency shifter 31. When the frequency of the echo signal changes, it will cause the atmospheric echo signal The intensity of the transmitted signal and the reflected signal on the filter 21 changes, one increases, the other decreases, and atmospheric wind speed information is extracted through this intensity information.

The invention discloses a direct detection wind measurement lidar based on a wide-spectrum light source. The invention adopts the way of two optical switches to make the emission laser and the atmospheric echo signal share a filter, and realizes the direct detection wind lidar based on the broad-spectrum light source. In order to improve the sensitivity of wind measurement, the invention proposes to use a frequency shifter to move the emitted laser frequency to the edge of the filter. When the atmospheric echo signal emits Doppler frequency shift, it will cause the atmospheric echo signal to change the intensity of the transmitted signal and the reflected signal on the filter, one increases and the other decreases. The atmospheric wind speed information is extracted by this intensity change information. Since the emitted laser and atmospheric echo signals pass through the filter within milliseconds or even microseconds, the present invention has the following advantages. First, the direct detection wind lidar is not sensitive to the frequency drift of the laser and the filter; , There is no need to use a narrow linewidth single-frequency laser, a wide-spectrum light source can increase the emitted laser power and reduce the cost of the laser; finally, no reference laser is needed, which simplifies the optical path.

The direct detection wind measurement lidar based on a broad-spectrum light source proposed in the present disclosure has the following beneficial effects:

(1) The present disclosure adopts a broad-spectrum laser diode, which reduces the requirement of the laser radar for the narrow line width of the laser. The broad-spectrum laser can increase the laser emission power and reduce the cost of the laser.

(2) The present disclosure proposes a scheme in which the emission laser and the atmospheric echo signal share a filter, and the emission laser is locked at the half height of the spectrum after convolution of the Fabry-Perot interferometer and the atmospheric echo signal through a laser frequency shifter. Because the emitted laser and atmospheric echo signals pass through the Fabry-Perot interferometer in microseconds, the drift of the Fabry-Perot interferometer is negligible in this time scale, which reduces the directivity. Detect the requirements of the wind lidar for the stability of the Fabry-Perot interferometer.

(3) The present disclosure proposes a solution for the emission of laser and atmospheric echo signals to share a filter. Since the position of the emission laser relative to the Fabry-Perot interferometer can be controlled by a laser frequency shifter, this eliminates the need for traditional Directly detect the reference light of the wind lidar, simplifying the optical path.

Those skilled in the art can understand that the features described in the various embodiments of the present disclosure and/or the claims may be combined or/or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the various embodiments of the present disclosure and/or the features described in the claims can be combined and/or combined in various ways. All these combinations and/or combinations fall within the scope of the present disclosure.

Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, those skilled in the art should understand that without departing from the spirit and scope of the present disclosure defined by the appended claims and their equivalents, Various changes in form and details are made to the present disclosure. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be defined not only by the appended claims but also by equivalents of the appended claims.

Claims

A wind measurement lidar based on a broad-spectrum light source, including:

Seed laser pulse generation unit (10), used to generate seed laser pulses;

The filtering unit (20) includes a filter (21), and the filter (21) is used to filter the generated seed laser pulses;

The laser frequency shifting and amplifying unit (30) is configured to receive the filtered seed laser pulse filtered by the filtering unit (20), and perform frequency shifting and amplifying the filtered seed laser pulse;

The laser transmitting and receiving unit (40) is used to receive the frequency-shifted and amplified seed laser pulses that have been frequency-shifted and amplified by the laser frequency-shifting and amplifying unit (30), and the frequency-shifted and amplified seed laser pulses The laser pulse is emitted into the atmosphere; the laser emitting and receiving unit (40) is also used to receive the atmospheric echo signal formed after the frequency-shifted and amplified seed laser pulse interacts with the atmosphere;

Wherein, the atmospheric echo signal received by the laser emitting and receiving unit (40) is filtered by the filter (21) to obtain a transmission signal and a reflection signal, respectively. These two signals have an impact on the atmospheric Doppler frequency. It is sensitive to movement, and atmospheric wind speed information can be obtained by inversion by measuring the intensity changes of the transmission signal and the reflection signal.
The wind measurement lidar based on a broad-spectrum light source according to claim 1, further comprising:

An echo signal detection unit (50) for detecting the transmission signal and the reflection signal;

The signal acquisition and processing unit (60) is used to collect the transmission signal and the reflection signal detected by the echo signal detection unit (50), and measure the intensity change of the transmission signal and the reflection signal, and To obtain atmospheric wind speed information.
The wind measurement lidar based on a broad-spectrum light source according to claim 2, wherein the filtering unit (20) further comprises:

The first optical switch (24) and the second optical switch (25) make the seed laser pulse and the atmospheric air through the gating manner of the first optical switch (24) and the second optical switch (25). The echo signal passes through the filter (21) in time sharing,

Wherein, the first optical switch (24) is connected to the seed laser pulse generating unit (10), the second optical switch (25) is connected to the laser frequency shift and amplification unit (30) and the echo The signal detection unit (50) is connected.
The wind measurement lidar based on a broad-spectrum light source according to claim 3, wherein the seed laser pulse is incident on the filter (21) after passing through the first optical channel of the first optical switch (24) The filter (21) filters the seed laser pulse to obtain the filtered seed laser pulse, and the filtered seed laser pulse is incident on the first optical channel of the second optical switch (25), Then input to the laser frequency shift and amplification unit (30).
The wind measurement lidar based on a broad-spectrum light source according to claim 4, wherein:

The filtering unit (20) further includes: a circulator (26), the circulator (26) is connected to the laser emitting and receiving unit (40) and the echo signal detecting unit (50),

Wherein, the atmospheric echo signal received by the laser emitting and receiving unit (40) passes through the circulator (26), and then enters the filter () through the second optical channel of the first optical switch (24). 21). After filtering by the filter (21), a transmission signal and a reflection signal are obtained respectively; after the transmission signal passes through the second optical channel of the second optical switch (25), it enters the echo signal detection Unit (50); the reflected signal enters the echo signal detection unit (50) after passing through the second optical channel of the first optical switch (24) and the circulator (26).
The wind measurement lidar based on a broad-spectrum light source according to claim 1, wherein the seed laser pulse unit (10) comprises:

Seed laser (11), used to generate seed laser;

A pulse generator (12), connected to the seed laser (11), for receiving the seed laser and generating pulse laser based on the seed laser;

The first filter (13) is connected to the pulse generator (12) and filters the pulsed laser light to form the seed laser pulse.
The wind measurement lidar based on a broad-spectrum light source according to claim 1, wherein the filter (21) includes a second filter (22) and a third filter (23), and the second filter ( 22) Connect with the third filter (23).
The wind measurement lidar based on a broad-spectrum light source according to claim 1, wherein the laser frequency shift and amplification unit (30) comprises:

A laser frequency shifter (31), connected to the filtering unit (20), and configured to receive the filtered seed laser pulse from the filtering unit (20), and perform frequency shift on the filtered seed laser pulse;

The delay fiber (32) is connected to the laser frequency shifter (31), and is used to receive the frequency-shifted seed laser pulse from the laser frequency shifter (31) and delay the frequency-shifted seed laser pulse, So as to separate the atmospheric echo signal from the seed laser pulse in the time domain;

The fiber amplifier (33) is connected to the delay fiber (32) and the laser transmitting and receiving unit (40), and is used to receive the delayed seed laser pulse from the delay fiber (32), and perform the The seed laser pulse is amplified to obtain the frequency-shifted and amplified seed laser pulse, and the frequency-shifted and amplified seed laser pulse is input to the laser emitting and receiving unit (40).
The wind measurement lidar based on a broad-spectrum light source according to claim 2, wherein the signal acquisition and processing unit (60) comprises:

Acquisition card (61), used to acquire the transmission signal and the reflection signal detected by the echo signal detection unit (50);

The processor (62) measures the intensity changes of the transmission signal and the reflection signal collected by the acquisition card (61), and obtains atmospheric wind speed information by inversion.
The wind measurement lidar based on a broad-spectrum light source according to claim 1, wherein the laser emitting and receiving unit (40) comprises:

A transmitting telescope (41) for transmitting the frequency-shifted and amplified seed laser pulses from the laser frequency shifting and amplifying unit (30) into the atmosphere;

The receiving telescope (42) is used for receiving the atmospheric echo signal from the atmosphere, and inputting the atmospheric echo signal into the filtering unit (20).