Wind measurement laser radar and wind measurement method thereof

Abstract

The invention relates to a wind measurement laser radar and a wind measurement method thereof. The wind measurement laser radar comprises a control device which sends out a first modulation signal and a second modulation signal; the light source module is used for emitting local oscillation light and signal light of continuous laser; the first acousto-optic modulator is used for receiving the signal light and carrying out frequency shift modulation and pulse modulation on the signal light based on the first modulation signal to obtain first modulation signal light; the second acousto-optic modulator is used for receiving the first modulation signal light and carrying out frequency shift modulation and pulse modulation on the first modulation signal light again based on the second modulation signal to obtain second modulation signal light; the telescope module receives the second modulation signal light, transmits the second modulation signal light to a to-be-measured target, and receives and outputs an echo signal reflected by the to-be-measured target; and the detection module is used for receiving the echo signal and the local oscillation light so as to generate a wind speed signal of the to-be-detected target. The wind measurement laser radar can greatly reduce or eliminate the trailing of the light waveform output by the combination of the two or more acousto-optic modulators.

Description

Technical Field

[0001] The present application relates to the technical field of wind measuring laser radar, and in particular to a wind measuring laser radar and a wind measuring method thereof. Background Art

[0002] With the rapid development of science and technology, the human need to control the natural environment has led to the rise of the wind power industry. In the wind power industry, effective terrain selection is required for wind turbines. Conventional wind towers have insurmountable restrictions on terrain and certain height requirements. The wind speed and direction at close range cannot be effectively and accurately measured, which often results in the wrong location selection of wind turbines, leading to endless problems of wind turbine tower collapse, causing significant economic losses.

[0003] Doppler laser wind radar mainly uses the Doppler effect to use the aerosol backscatter signal and the radar's local oscillator light as the beat frequency to obtain the Doppler frequency shift of the scattered signal, thereby obtaining wind speed information. This can effectively solve the shortcomings of wind towers, and it can dynamically adjust wind measurement, has ultra-high wind direction and wind speed accuracy, and is convenient and the price is far lower than the cost of wind towers.

[0004] Traditional Doppler laser wind radars are divided into two categories: continuous wave laser wind radars and pulsed laser wind radars. Continuous wave radars, as the name implies, emit continuous lasers to detect atmospheric wind fields. The advantage is that the blind spot is small, but the disadvantage is that it can only measure short-range wind speed and direction. Pulsed laser radars detect atmospheric wind fields by emitting a series of pulses. The advantage is that it can measure long-range wind speed and direction, but the disadvantage is that the blind spot is large. Summary of the invention

[0005] Based on this, it is necessary to provide a wind measuring lidar and a wind measuring method thereof that can reduce blind spots in order to address the above technical problems.

[0006] In a first aspect, the present application provides a wind measuring laser radar, comprising: a control device, which emits a first modulation signal and a second modulation signal; a light source module, which emits a local oscillator light and a signal light, wherein the local oscillator light and the signal light are continuous lasers; a first acousto-optic modulator, which is loaded with a first modulation signal, receives the signal light, and performs frequency shift modulation and pulse modulation on the signal light based on the first modulation signal to obtain a first modulated signal light; a second acousto-optic modulator, which is loaded with a second modulation signal, receives the first modulated signal light, and performs frequency shift modulation and pulse modulation on the first modulated signal light again based on the second modulation signal to obtain a second modulated signal light; a telescope module, which receives the second modulated signal light and transmits the second modulated signal light to a target to be measured, receives and outputs an echo signal reflected by the target to be measured; and a detection module, which receives the echo signal and the local oscillator light, thereby generating a wind speed signal of the target to be measured.

[0007] In one embodiment, the control device includes: a control unit for issuing a modulation parameter instruction; an FPGA module for receiving the modulation parameter instruction and generating a first drive modulation signal and a second drive modulation signal based on the modulation parameter instruction; a first acousto-optic driver for receiving the first drive modulation signal and generating a first modulation signal based on the first drive modulation signal; a second acousto-optic driver for receiving the second drive modulation signal and generating a second modulation signal based on the second drive modulation signal; wherein the first modulation signal and the second modulation signal are adjusted according to the pulse timing of the FPGA module so that the first modulation signal and the second modulation signal are time synchronized.

[0008] In one of the embodiments, the wind measuring laser radar also includes: a first amplifying module, which is arranged between the first acousto-optic modulator and the second acousto-optic modulator, and amplifies the first modulated signal light; wherein the first amplifying module also brings a delay to the first modulated signal light; wherein the control device also generates a delay parameter based on the delay, and modulates the first modulated signal and / or the second modulated signal based on the delay parameter, so that the time when the first acousto-optic modulator modulates the signal light is aligned with the time when the second acousto-optic modulator modulates the first modulated signal light.

[0009] In one of the embodiments, the wind measuring laser radar also includes: a second amplification module, which is arranged between the second acousto-optic modulator and the telescope module, and amplifies the second modulated signal light; the second amplification module is also arranged between the telescope module and the detection module, and amplifies the echo signal output by the telescope module and transmits it to the detection module.

[0010] In one of the embodiments, the first driving modulation signal is set as an analog signal.

[0011] In one embodiment, the second driving modulation signal is configured as a digital signal.

[0012] In one embodiment, the first modulated signal light has a first pulse width, and the second modulated signal light has a second pulse width; the first pulse width is greater than the second pulse width.

[0013] In one embodiment, the detection module includes: a coupler, coupling the echo signal and the local oscillator light, mixing the echo signal and the local oscillator light to obtain a coupled light signal; a balanced detector, receiving the coupled light signal, beating the coupled light signal, and converting the coupled light signal after the beating into an electrical signal to obtain a wind speed signal of the target to be measured.

[0014] In the second aspect, the present application also provides a wind measurement method using a wind measuring lidar, the method comprising: sending a first modulation signal and a second modulation signal through a control device; controlling a light source module to send a local oscillator light and a signal light, wherein the local oscillator light and the signal light are continuous lasers; performing frequency shift modulation and pulse modulation on the signal light through a first acousto-optic modulator based on the first modulation signal to obtain a first modulated signal light; performing frequency shift modulation and pulse modulation on the first modulated signal light again through a second acousto-optic modulator based on the second modulation signal to obtain a second modulated signal light; the second modulated signal light is incident on a target to be measured via a telescope module, and an echo signal reflected by the target to be measured is received and output via the telescope module; controlling a detection module to receive the echo signal and the local oscillator light, and generating a wind speed signal of the target to be measured based on the echo signal and the local oscillator light.

[0015] In one of the embodiments, the second modulated signal light includes multiple pulses, and the wind speed signal of the target to be measured is generated based on the echo signal and the local oscillator light, including: mixing the echo signal with the local oscillator light and then beating the frequency again to generate the wind speed signal of the target to be measured; the wind speed signal includes multiple echo signals reflected after the pulses are incident on the target to be measured, and the echo signal includes multiple echo pulse signals; within the receiving time of each pulse signal of the multiple echo pulse signals, the range gate is divided; the range gate is divided with the end face signal emitted by the radar as the starting point, and a range gate is calibrated at every predetermined time interval; multiple echo pulse signals are accumulated to obtain an accumulated echo pulse signal; the accumulated echo pulse signal is filtered to remove noise to obtain a pending wind speed signal; when the pending wind speed signal has no abnormal spectrum, the pending wind speed signal is the wind speed signal of the target to be measured.

[0016] The above-mentioned wind measuring laser radar and wind measuring method thereof load a first modulation signal on the first acousto-optic modulator, and perform frequency shift modulation and pulse modulation on the signal light based on the first modulation signal to obtain a first modulated signal light; and load a second modulation signal on the second acousto-optic modulator, and perform frequency shift modulation and pulse modulation on the first modulated signal light again based on the second modulation signal to obtain a second modulated signal light, and transmit the second modulated signal light to the target to be measured to obtain an echo signal reflected by the target to be measured, and the echo signal carries the wind speed information of the target to be measured. By loading different modulation signals on the first acousto-optic modulator and the second acousto-optic modulator, the tail of the optical waveform finally combined and output by two or more acousto-optic modulators is greatly reduced or eliminated, and the pulse width becomes narrower without affecting the power, thereby preventing the leakage of excess frequency due to the widening of the pulse width. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 This is a schematic diagram of the principle of the pulse blind area of ​​the wind laser radar;

[0019] Figure 2 A schematic diagram of the structure of a wind laser radar in one embodiment;

[0020] Figure 3 A clock timing diagram of an FPGA chip in one embodiment;

[0021] Figure 4 is a schematic diagram of a pulse simulated sine wave signal of a first acousto-optic driver in one embodiment;

[0022] Figure 5 is a schematic diagram of a pulsed digital sine wave signal of a second acousto-optic driver in one embodiment;

[0023] Figure 6 is a schematic diagram of a simulated optical signal of a first modulated signal light outputted by a first acousto-optic modulator in one embodiment;

[0024] Figure 7 is a schematic diagram of a simulated optical signal of a second modulated signal light outputted by a second acousto-optic modulator in one embodiment;

[0025] Figure 8 is a schematic diagram of a timing diagram of an optical signal output by a first acousto-optic modulator and a timing diagram of an optical signal output by a second acousto-optic modulator under the same electrical signal triggering in one embodiment, wherein there is a time delay between the optical signal output by the first acousto-optic modulator and the optical signal output by the second acousto-optic modulator;

[0026] Fig. 9 is a schematic diagram of a timing diagram of an optical signal output by a first acousto-optic modulator and a timing diagram of an optical signal output by a second acousto-optic modulator under the same electrical signal triggering in one embodiment, wherein there is no delay between the optical signal output by the first acousto-optic modulator and the optical signal output by the second acousto-optic modulator;

[0027] Fig.10 It is a schematic diagram of a signal with abnormal beat frequency detected by a detector when tailing is not eliminated in one embodiment;

[0028] Fig.11A schematic diagram of a beat frequency signal detected by a detector after tailing is eliminated in one embodiment;

[0029] Fig.12 A schematic diagram of a tail generated by an optical signal passing through an acousto-optic modulator in one embodiment;

[0030] Fig.13 A schematic diagram of a state in which tailing cannot be eliminated in an embodiment;

[0031] Fig.14 A schematic diagram of a state after tailing is eliminated in one embodiment;

[0032] Fig.15 A schematic diagram of a flow chart of a wind measurement method using a wind measurement laser radar in one embodiment;

[0033] Fig.16 A schematic flow chart of a wind measurement method using a wind measurement laser radar in another embodiment;

[0034] Fig.17 A schematic diagram of the steps of extracting wind speed information from an echo signal in one embodiment;

[0035] Fig.18 A schematic diagram of the division of range gates of a wind laser radar in one embodiment;

[0036] Fig.19 is a schematic diagram of a situation where an abnormal spectrum exists at a target distance in one embodiment;

[0037] Fig. 20 FIG. 1 is a schematic diagram of a situation in which there is no abnormal spectrum at the target distance after the tail is eliminated in one embodiment.

[0038] Description of reference numerals:

[0039] 1. Control device; 2. Light source module; 3. First acousto-optic modulator; 4. First amplification module; 5. Second acousto-optic modulator; 6. Second amplification module; 7. Telescope module; 8. Detection module; 11. Control unit; 12. FPGA module; 13. First acousto-optic driver; 14. Second acousto-optic driver; 81. Balanced detector; 82. Coupler. DETAILED DESCRIPTION

[0040] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0042] It can be understood that the terms "first", "second", etc. used in the present application can be used in this article to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0043] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0044] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0045] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0046] As described in the background technology, the wind laser radar in the prior art has the problem of large blind spots. Blind spots and range are both important parameter indicators for measuring laser wind radar. The smaller the blind spot, the closer the wind speed and direction can be measured, so that it can be clear how much foundation strength is required at the location of the wind turbine tower, greatly reducing the risk of the wind turbine tower collapsing and the blades sweeping the tower due to excessive low-altitude wind speeds; the longer the range, the farther the wind speed and direction can be measured. With the development of wind laser radar, the blades are getting bigger and bigger, and the required measurement height is getting higher and higher. Then there is a need for a laser wind radar that can meet both the blind spot requirements and long-distance detection.

[0047] We know that the main indicator that affects the blind spot is the pulse width, which is usually measured in nanoseconds (ns). When the first pulse is completely emitted by the radar and reaches the atmosphere, it takes a pulse width of time to be received by the receiver. This time is converted into distance, which is the radar's measurement blind spot. Figure 1 The figure shows the principle diagram of the pulse blind area of ​​the wind laser radar. The blind area formula is shown in formula (1):

[0048] (1)

[0049] Where D is the blind spot distance, c is the speed of light, and Δt is the time it takes for a single pulse beam to travel.

[0050] Therefore, it can be known that the actual distance of the blind spot is the time corresponding to one pulse width.

[0051] Based on the above reasons, the present invention provides a wind measurement laser radar wind measurement solution that can reduce the blind area. In one embodiment, Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a wind laser radar according to an embodiment of the present application. Figure 2 , a wind measuring laser radar is provided, comprising: a control device 1, which sends out a first modulation signal and a second modulation signal; a light source module 2, which sends out a local oscillation light and a signal light, wherein the local oscillation light and the signal light are continuous lasers; a first acousto-optic modulator 3, which is loaded with a first modulation signal, receives the signal light, and performs frequency shift modulation and pulse modulation on the signal light based on the first modulation signal to obtain a first modulated signal light; a second acousto-optic modulator 5, which is loaded with a second modulation signal, receives the first modulated signal light, and performs frequency shift modulation and pulse modulation on the first modulated signal light again based on the second modulation signal to obtain a second modulated signal light; a telescope module 7, which receives the second modulated signal light, transmits the second modulated signal light to a target to be measured, receives and outputs an echo signal reflected by the target to be measured; a detection module 8, which receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be measured.

[0052] Exemplarily, the control device 1 sends the values ​​of the first modulation signal and the second modulation signal to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through a software program; at this time, the light source module 2 emits a continuous laser, including local oscillation light and signal light, wherein the signal light is frequency-shifted after passing through the first acousto-optic modulator 3 loaded with the first modulation signal, and the signal light is converted into a pulse laser, thereby obtaining the first modulated signal light; the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulation signal again, and is frequency-shifted and pulse-modulated again by the second acousto-optic modulator 5, thereby obtaining the second modulated signal light. The second modulated signal light enters the telescope module 7, and the second modulated signal light modulated into a pulse laser is emitted into the atmosphere, and the backscattered light, i.e., the echo signal, that passes through the atmosphere returns to the telescope module 7 again, and then enters the detection module 8. The detection module 8 receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be measured. The control device 1 may be a computer or a host computer, the light source module 2 may be a seed source module, and further, the light source module 2 includes a laser light source and a beam splitter, so that the continuous laser light emitted by the laser light source is split into a local oscillator light and a signal light by the beam splitter. It can be understood that the first modulation signal may be an analog signal or a digital signal, and the second modulation signal may also be an analog signal or a digital signal.

[0053] In the above-mentioned wind measuring laser radar, a first modulation signal is loaded on the first acousto-optic modulator 3, and the signal light is frequency-shift modulated and pulse-modulated based on the first modulation signal to obtain a first modulated signal light; and a second modulation signal is loaded on the second acousto-optic modulator 5, and the first modulated signal light is frequency-shift modulated and pulse-modulated again based on the second modulation signal to obtain a second modulated signal light, and the second modulated signal light is emitted to the target to be measured to obtain an echo signal reflected by the target to be measured, and the echo signal carries the wind speed information of the target to be measured. By loading different modulation signals on the first acousto-optic modulator 3 and the second acousto-optic modulator 5, the tail of the optical waveform finally combined and output by two or more acousto-optic modulators is greatly reduced or eliminated, and the pulse width becomes narrower without affecting the power, thereby preventing the leakage of excess frequency due to pulse width widening.

[0054] In one embodiment, please refer again to Figure 2The control device 1 includes: a control unit 11, which is used to issue a modulation parameter instruction; an FPGA module 12, which receives the modulation parameter instruction and generates the first drive modulation signal and the second drive modulation signal based on the modulation parameter instruction; a first acousto-optic driver 13, which receives the first drive modulation signal and generates a first modulation signal based on the first drive modulation signal; a second acousto-optic driver 14, which receives the second drive modulation signal and generates a second modulation signal based on the second drive modulation signal; wherein, according to the pulse timing of the FPGA module 12, the first modulation signal and the second modulation signal are adjusted so that the first modulation signal and the second modulation signal are time synchronized.

[0055] Exemplarily, the control unit 11 sends the modulation parameter instruction to the FPGA (field-programmable gate array) module through the software program. After receiving the modulation parameter instruction, the FPGA module 12 generates a first modulation signal and transmits it to the first acousto-optic driver 13 through the RF line, generates a second modulation signal and transmits it to the second acousto-optic driver 14 through the RF line, and converts the sine wave continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 into a pulsed sine wave, thereby obtaining the first modulation signal and the second modulation signal, and the first modulation signal and the second modulation signal are again sent to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through the RF line; at this time, the light source module 2 emits a continuous laser, including a local oscillation light and a signal light, wherein the signal light is frequency-shifted after passing through the first acousto-optic modulator 3 loaded with the first modulation signal, and the signal light is converted into a pulsed laser, thereby obtaining the first modulated signal light; the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulation signal again, and is frequency-shifted and pulse-modulated again by the second acousto-optic modulator 5 to obtain the second modulated signal light. At this time, according to the pulse timing of the FPGA module 12, the first modulation signal and the second modulation signal are adjusted so that the first modulation signal and the second modulation signal are synchronized in time. The second modulation signal light enters the telescope module 7 and emits the second modulation signal light modulated into a pulsed laser into the atmosphere. The backscattered light, i.e., the echo signal, passes through the atmosphere and returns to the telescope module 7 again and enters the detection module 8. The detection module 8 receives the echo signal and the local oscillator light, thereby generating a wind speed signal of the target to be measured. The control device 1 can be a computer or a host computer, and the light source module 2 can be a seed source module. Furthermore, the light source module 2 includes a laser light source and a beam splitter, so that the continuous laser emitted by the laser light source is split into local oscillator light and signal light through the beam splitter. The FPGA module 12 can be a programmable gate logic control chip circuit.

[0056] In this embodiment, the laser wind measurement radar adjusts the mutual delay of two or more stages of acousto-optic modulators through the FPGA (field programmable gate array) on the hardware control circuit, so that the acousto-optic time of the next stage is tangent to the falling edge of the light waveform output by the previous stage acousto-optic modulator. In this way, the tailing phenomenon in the light waveform output by the previous stage acousto-optic modulator can be eliminated, and the blind area distance of the laser radar can be reduced.

[0057] In an exemplary embodiment, the first drive modulation signal is set as an analog signal.

[0058] In an exemplary embodiment, the second driving modulation signal is configured as a digital signal.

[0059] Exemplarily, the control unit 11 sends the modulation parameter instruction to the FPGA module 12 through the software program. After receiving the modulation parameter instruction, the FPGA module 12 generates a first modulation signal of an analog signal and transmits it to the first acousto-optic driver 13 through the radio frequency line, and generates a second modulation signal of a digital signal with the same value as the analog signal and transmits it to the second acousto-optic driver 14 through the radio frequency line, and converts the sine wave continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 into a pulsed sine wave, which is again sent to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through the radio frequency line; at this time, the light source module 2 emits a continuous laser, including a local oscillation light and a signal light, wherein the signal light is transmitted by loading The first modulated signal is frequency-shifted after the first acousto-optic modulator 3, and the signal light is converted into a pulsed laser, thereby obtaining the first modulated signal light; the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulated signal again, and at this time, the control unit 11 needs to dynamically adjust the delay before and after the FPGA module 12 to align the time of the first acousto-optic modulator 3 with the second acousto-optic modulator 5, so that the first modulated signal light can obtain the second modulated signal light through the second acousto-optic modulator 5, and the second modulated signal light enters the telescope module 7 to emit the second modulated signal light modulated into a pulsed laser into the atmosphere, and the backscattered light, that is, the echo signal, that passes through the atmosphere returns to the telescope module 7 again and enters the detection module 8. The detection module 8 receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be measured. The control device 1 can be a computer or a host computer, and the light source module 2 can be a seed source module. Further, the light source module 2 includes a laser light source and a beam splitter, so that the continuous laser emitted by the laser light source is split into a local oscillation light and a signal light through the beam splitter. Optionally, the FPGA module 12 is a programmable gate logic control chip circuit, the first acousto-optic driver 13 can be an analog acousto-optic driver, the second acousto-optic driver 14 is a digital acousto-optic driver, the first acousto-optic modulator 3 is an analog acousto-optic modulator, and the second acousto-optic modulator 5 is a digital acousto-optic modulator.

[0060] It can be understood that since the response of the analog signal is a gradual process, while the response of the digital signal is more direct and rapid, for example, after the same modulation parameter instruction is issued, the response process of the analog signal is 10, 20, 30, 40, 50, 60, 50, 40, 30, 20, 10, while the response process of the digital signal is 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0. In this embodiment, by setting the first modulation signal to an analog signal and setting the second modulation signal to a digital signal, the fast response feature of the digital signal can be fully utilized, thereby facilitating the subsequent rapid cutoff of the tailing.

[0061] In an exemplary embodiment, the wind measuring laser radar also includes: a first amplifying module 4, which is arranged between the first acousto-optic modulator 3 and the second acousto-optic modulator 5, and amplifies the first modulated signal light; wherein the first amplifying module 4 also brings a delay to the first modulated signal light; wherein the control device 1 also generates a delay parameter based on the delay, and modulates the first modulated signal and / or the second modulated signal based on the delay parameter, so that the time when the first acousto-optic modulator 3 modulates the signal light and the time when the second acousto-optic modulator 5 modulates the first modulated signal light are aligned.

[0062] Exemplarily, the control unit 11 sends the modulation parameter instruction to the FPGA module 12 through the software program. After receiving the modulation parameter instruction, the FPGA module 12 generates a first modulation signal set as an analog signal and transmits it to the first acousto-optic driver 13 through the radio frequency line, and generates a second modulation signal of a digital signal with the same value as the analog signal and transmits it to the second acousto-optic driver 14 through the radio frequency line, and converts the sine wave continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 into a pulsed sine wave, which is again sent to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through the radio frequency line; at this time, a continuous laser is emitted by the light source module 2, including local oscillation light and signal light, wherein the signal light is frequency-shifted after passing through the first acousto-optic modulator 3 loaded with the first modulation signal. , and convert the signal light into a pulsed laser, thereby obtaining a first modulated signal light; after pre-amplification by the first amplifier module 4, the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulated signal again. At this time, since the first amplifier module 4 also brings delay to the first modulated signal light, it is necessary to dynamically adjust the delay before and after the FPGA module 12 through the control unit 11 to align the time of the first acousto-optic modulator 3 with the second acousto-optic modulator 5. Only then can the first modulated signal light pass through the second acousto-optic modulator 5 to obtain the second modulated signal light. The second modulated signal light enters the telescope module 7 and emits the second modulated signal light modulated into a pulsed laser into the atmosphere. The backscattered light, i.e., the echo signal, that passes through the atmosphere returns to the telescope module 7 again and enters the detection module 8. The detection module 8 receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be measured. Among them, the first amplifier module 4 is a low-noise amplifier module, which can be an EDFA module.

[0063] Among them, the FPGA module 12 uses different clock signals to convert the programmed analog or digital signals used for triggering into radio frequency electrical signals through hardware filtering, voltage control, etc., and then sends them to the first acousto-optic driver 13 and the second acousto-optic driver 14 for pulse modulation.

[0064] Please refer to Figure 3 , Figure 3 This is a clock timing diagram of an FPGA chip in an embodiment, which adjusts the analog and digital time delays of the two outputs to ensure the time synchronization of the two signals. There is a main signal in the signal for stabilizing the frequency, and the other two signals are provided to the acousto-optic driver for frequency modulation conversion.

[0065] in, Figure 3 In the figure, TRIG_syn represents the synchronization signal clock, through which it can be confirmed that each triggered signal is of the same time, avoiding time staggering and inability to align; the second curve is the response curve of the first acousto-optic driver 13, and the third curve is the response curve of the second acousto-optic driver 14. The delay time is due to the time delay caused by the difference in the length of the optical fiber or RF line for each triggered output signal. It is necessary to adjust the misaligned time through the signal trigger adjustment of the FPGA.

[0066] After the first drive modulation signal set as an analog signal and the second drive modulation signal set as a digital signal given by the FPGA pass through the first acousto-optic driver 13 and the second acousto-optic driver 14, the sine wave signal continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 is converted into a pulse analog sine wave signal and a pulse digital sine wave signal, such as Figure 4 and Figure 5 As shown, Figure 4 is a schematic diagram of a pulse simulated sine wave signal of the first acousto-optic driver 13 in one embodiment, Figure 5 FIG. 4 is a schematic diagram of a pulse digital sine wave signal of the second acousto-optic driver 14 in one embodiment.

[0067] The electrical signal output by the first acousto-optic driver 13 is transmitted to the first acousto-optic modulator 3 through the radio frequency line, and the electrical signal output by the second acousto-optic driver 14 is transmitted to the second acousto-optic modulator 5 through the radio frequency line. The acousto-optic transducers inside the first acousto-optic modulator 3 and the second acousto-optic modulator 5 transmit sound waves with the same frequency as the driver to vibrate the crystal, thereby changing the refractive index of the crystal, so that the original input continuous light is transformed into a pulse light source. Figure 6 and Figure 6 As shown, Figure 6 is a schematic diagram of a simulated optical signal of the first modulated signal light output by the first acousto-optic modulator 3, Figure 7is a schematic diagram of an analog optical signal of the second modulated signal light outputted by the second acousto-optic modulator 5.

[0068] Since the propagation speed of light in the optical fiber is v=c / n, and there is a certain optical fiber distance L=vt between the first AOM 3 and the second AOM 5, there is a certain time delay, such as Figure 8 The above is a schematic diagram of the timing diagram of the optical signal output by the first AOM 3 and the timing diagram of the optical signal output by the second AOM 5 under the same electrical signal triggering condition. At this time, there is a delay between the optical signal output by the first AOM 3 and the optical signal output by the second AOM 5. If it is desired that the first modulated signal light modulated by the first AOM 3 can be output by the second AOM 5, the timing of the two AOMs needs to be aligned. In this embodiment, the delay of the two optical signals is adjusted by the FPGA clock, and the adjustment result is as follows: Fig. 9 shown. Fig. 9 The schematic diagram shows the timing diagram of the optical signal output by the first AOM 3 and the timing diagram of the optical signal output by the second AOM 5 under the same electrical signal triggering condition, and at this time, there is no delay between the optical signal output by the first AOM 3 and the optical signal output by the second AOM 5. The first modulated signal light modulated by the first AOM 3 can pass through the second AOM 5 and output the second modulated signal light.

[0069] In an exemplary embodiment, the wind measuring lidar also includes: a second amplifying module 6, which is arranged between the second acousto-optic modulator 5 and the telescope module 7, and amplifies the second modulated signal light; the second amplifying module 6 is also arranged between the telescope module 7 and the detection module 8, and amplifies the echo signal output by the telescope module 7 and transmits it to the detection module 8.

[0070] Exemplarily, the control unit 11 sends the modulation parameter instruction to the FPGA module 12 through the software program. After receiving the modulation parameter instruction, the FPGA module 12 generates a first modulation signal set as an analog signal and transmits it to the first acousto-optic driver 13 through the radio frequency line, and generates a second modulation signal of a digital signal with the same value as the analog signal and transmits it to the second acousto-optic driver 14 through the radio frequency line, and converts the sine wave continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 into a pulsed sine wave, which is again sent to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through the radio frequency line; at this time, the light source module 2 emits a continuous laser, including a local oscillation light and a signal light, wherein the signal light is frequency-shifted after passing through the first acousto-optic modulator 3 loaded with the first modulation signal, And the signal light is converted into a pulsed laser, thereby obtaining a first modulated signal light; after pre-amplification through the first amplifier module 4, the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulated signal again. At this time, the control unit 11 needs to dynamically adjust the delay before and after the FPGA module 12 to align the time of the first acousto-optic modulator 3 with the second acousto-optic modulator 5. The first modulated signal light can obtain the second modulated signal light through the second acousto-optic modulator 5. The second modulated signal light enters the second amplifier module 6 for final energy amplification and then enters the telescope module 7 to emit the second modulated signal light modulated into a pulsed laser into the atmosphere. The backscattered light, i.e., the echo signal, that passes through the atmosphere returns to the telescope module 7 again and enters the detection module 8 through the second amplifier module 6. The detection module 8 receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be measured. The second amplifier module 6 can be a power amplifier module, such as an EYDFA module.

[0071] In an exemplary embodiment, the detection module 8 includes: a coupler 82, which couples the echo signal and the local oscillator light, mixes the echo signal and the local oscillator light, and obtains a coupled light signal; a balanced detector 81, which receives the coupled light signal, beats the coupled light signal, and converts the coupled light signal after the beat into an electrical signal to obtain a wind speed signal of the target to be measured.

[0072] Exemplarily, the control unit 11 sends the modulation parameter instruction to the FPGA module 12 through the software program. After receiving the modulation parameter instruction, the FPGA module 12 generates a first modulation signal set as an analog signal and transmits it to the first acousto-optic driver 13 through the radio frequency line, and generates a second modulation signal of a digital signal with the same value as the analog signal and transmits it to the second acousto-optic driver 14 through the radio frequency line, and converts the sine wave continuously transmitted by the first acousto-optic driver 13 and the second acousto-optic driver 14 into a pulsed sine wave, which is again sent to the first acousto-optic modulator 3 and the second acousto-optic modulator 5 through the radio frequency line; at this time, a continuous laser is emitted by the light source module 2, including local oscillation light and signal light, wherein the signal light is frequency-shifted after passing through the first acousto-optic modulator 3 loaded with the first modulation signal, and the signal light is converted into a pulsed laser, thereby obtaining a first modulated signal light; after passing through the first amplification module After pre-amplification in block 4, the first modulated signal light enters the second acousto-optic modulator 5 loaded with the second modulated signal again. At this time, the control unit 11 needs to dynamically adjust the delay before and after the FPGA module 12 to align the time of the first acousto-optic modulator 3 with the first acousto-optic modulator 3. The first modulated signal light can obtain the second modulated signal light through the second acousto-optic modulator 5. The second modulated signal light enters the second acousto-optic modulator 5 for final energy amplification and then enters the telescope module 7 to emit the second modulated signal light modulated into a pulsed laser into the atmosphere. After the backscattered light, i.e., the echo signal, passes through the atmosphere and returns to the telescope module 7 again, it enters the coupler 82 through the second amplification module 6 and the local oscillator light emitted by the light source module 2 for mixing to obtain a coupled light signal. The coupled light signal enters the balanced detector 81 and is photoelectrically converted into an electrical signal beat frequency and then output to obtain the wind speed signal of the target to be measured. The coupler 82 can be a fiber coupler 82.

[0073] In an exemplary embodiment, the first modulated signal light has a first pulse width, and the second modulated signal light has a second pulse width; the first pulse width is greater than or equal to the second pulse width.

[0074] Due to the characteristics of the AOM itself, after the signal is transmitted, the sound wave has not yet stopped propagating in the crystal of the AOM, and there is a slow silencing process. During this period, when the light passes through the crystal of the AOM, it will still be repeatedly modulated by the crystal, so this delay time is also called tailing. The performance brought by tailing will affect the time of normal pulses, and in the process of radar detection, it will cause abnormal spectrum state, affecting the actual detection performance and the distance of the radar blind area. Please refer to Fig.10 and Fig.11 , Fig.10 It is a schematic diagram of an abnormal beat frequency signal detected by the detector when the tailing is not eliminated; Fig.11 Schematic diagram of the beat frequency signal detected by the detector after eliminating the tailing.

[0075] Exemplarily, the first modulated signal light has a first pulse width, and the second modulated signal light has a second pulse width; the first pulse width is greater than or equal to the second pulse width. The first pulse width is large, which can facilitate the second acousto-optic modulator 5 to cut the first modulated signal light, thereby obtaining a second pulse width less than or equal to the first pulse width.

[0076] Please refer to Fig.12 , Fig.12 Schematic diagram of the tail generated by the optical signal passing through the acousto-optic modulator. Fig.12 The effective pulse time and tail time in an optical pulse signal, as well as the area where the tail appears, are shown. It can be seen that the tail appears at the tail end of the optical pulse signal.

[0077] Please refer to Fig.13 , Fig.13 Schematic diagram when the tail cannot be eliminated. When the first drive modulation signal of the first AOM 3 is set to an analog signal, the second drive modulation signal of the second AOM 5 is also set to an analog signal, and the relative time of the second AOM 5 and the first AOM 3 does not coincide, the tail generated after the light passes through the first AOM 3 cannot be eliminated. Of course, at this time, the tail generated after the light passes through the first AOM 3 can be cut off by setting the pulse cut-off time of the second AOM 5 before the cut-off time of the same pulse of the first AOM 3.

[0078] Optionally, when the first driving modulation signal of the first AOM 3 is set to an analog signal, the second driving modulation signal of the second AOM 5 is set to a digital signal, and the relative time of the second AOM 5 and the first AOM 3 coincides, the tail generated by the light passing through the AOM can be cut off, such as Fig.14 The figure shows the state after the tail is eliminated.

[0079] In this embodiment, when the time of the first AOM 3 does not coincide with the relative time of the second AOM 5, the first modulated signal light cannot effectively pass through the pulse gate of the second AOM 5 to emit light normally, but is blocked by the second AOM 5. By adjusting the delay time of the second AOM 5, the time delay of the second AOM 5 coincides with the relative delay of the first AOM 3. When the driving modulation signal of the first AOM 3 is an analog signal, the falling time of the optical pulse of the first AOM 3 is relatively slow, about 50ns~60ns. When the driving modulation signal of the second AOM 5 is a digital signal, the falling edge speed of the second AOM 5 is relatively fast, about 20ns. The ultra-fast fall time of the second AOM 5 is used to block the fall time of the first AOM 3, and the laser output by the first AOM 3, for example, 30ns, is blocked, so that the tail of the optical waveform finally combined and output by the two AOMs can be greatly reduced or eliminated. Without affecting the power, the pulse width becomes narrower, thereby preventing the leakage of excess frequency caused by the pulse width widening.

[0080] Based on the same inventive concept, the embodiment of the present application also provides a wind measurement method using a wind laser radar. The solution provided by the method is similar to the solution described in the above wind laser radar. Therefore, the specific limitations of the wind measurement method embodiments of one or more wind laser radars provided below can be found in the above limitations on wind laser radars, which will not be repeated here. Fig.15 , Fig.15 15 is a flow chart of a wind measurement method using a wind laser radar in an embodiment, the method comprising: steps 1502 to 1510.

[0081] Step 1502 : The control device 1 sends a first modulation signal and a second modulation signal.

[0082] Step 1504 , control the light source module 2 to emit local oscillator light and signal light, where the local oscillator light and the signal light are continuous lasers.

[0083] Step 1506: Based on the first modulation signal, the signal light is subjected to frequency shift modulation and pulse modulation by the first acousto-optic modulator 3 to obtain a first modulated signal light.

[0084] Step 1508: Based on the second modulation signal, the first modulated signal light is frequency-shift modulated and pulse-modulated again by the second acousto-optic modulator 5 to obtain a second modulated signal light; the second modulated signal light is incident on the target to be measured via the telescope module 7, and the echo signal reflected by the target to be measured is received and output via the telescope module 7.

[0085] Step 1510: Control the detection module 8 to receive the echo signal and the local oscillation light, and generate a wind speed signal of the target to be measured based on the echo signal and the local oscillation light.

[0086] In an exemplary embodiment, the second modulated signal light includes a plurality of pulses, such as Fig.16 As shown, generating the wind speed signal of the target to be measured based on the echo signal and the local oscillation light includes steps 1602 to 1608.

[0087] Step 1602, the echo signal is mixed with the local oscillator light and then beat again to generate a wind speed signal of the target to be measured; the wind speed signal includes echo signals reflected after multiple pulses are incident on the target to be measured, and the echo signal includes multiple echo pulse signals.

[0088] Step 1604, within the reception time of each pulse signal of the multiple echo pulse signals, a range gate is divided; the range gate division is based on the end face signal emitted by the radar as a starting point, and a range gate is calibrated at every predetermined time interval.

[0089] Step 1606, accumulating the multiple echo pulse signals to obtain an accumulated echo pulse signal; filtering the accumulated echo pulse signal to remove noise to obtain a pending wind speed signal.

[0090] Step 1608: When the pending wind speed signal has no abnormal spectrum, the pending wind speed signal is the wind speed signal of the target to be measured.

[0091] Please also refer to Fig.17 , Fig.17 FIG. 1 is a schematic diagram of the steps of extracting wind speed information from an echo signal in an embodiment. Exemplarily, the echo signal reflected by the second modulated signal light through the atmosphere is mixed with the initial local oscillator light of the radar and then beat again, thereby obtaining effective wind speed data in the atmosphere. The echo signal and the local oscillator light are shown in formula (2) and formula (3) respectively.

[0092] (2)

[0093] (3)

[0094] Among them, E S (t) represents the light field intensity of the echo signal at the same time; E L (t) represents the light field intensity of the local oscillator light at the same time; U S Indicates the amplitude of the signal light; U L represents the amplitude of the local oscillator light; w S 、w L They are used to represent the frequencies of the echo signal light and the local oscillator light respectively; φ S ,φ L Indicates the initial phase distribution of the echo signal and the local oscillator light.

[0095] like Fig.17As shown, the signal is first collected, and the echo signal and the local oscillator light are beat on the balanced detector. After A / D conversion, noise filtering, signal amplification, etc., the echo signal raw data is formed after entering the computer. The echo signal of each pulse will form a raw data, thus completing the signal acquisition process.

[0096] Then the collected signals are processed. In order to effectively obtain the spatial resolution information corresponding to the wind speed, the range gate is divided within each pulse signal receiving time. Generally, the end face signal emitted by the radar is used as the starting point, and each interval is used as a range gate calibration, such as Fig.18 The figure shows the schematic diagram of the range gate division of the wind laser radar.

[0097] Exemplarily, the power spectrum of the echo signal is estimated. Optionally, the frequency of the time domain signal is evaluated using Fourier transform (FT), as shown in formula (4).

[0098] (4)

[0099] In formula (4), ω represents frequency, t represents time, and e -iωt Represents a complex function.

[0100] The spectrum data after power spectrum estimation is accumulated and denoised to obtain the accumulated echo pulse signal. Since the aerosol particles in the atmosphere are constantly fluctuating, there is a certain jitter in the echo signals and noise between different pulses. Through the accumulation method, the echo signals of the same frequency will be superimposed, and the noise of different frequencies will be eliminated, effectively improving the signal-to-noise ratio of detection.

[0101] Subsequently, the spectrum of the accumulated echo pulse signal is corrected. By comparing it with the frequency of the radar, the frequency of the echo signal can be corrected. In the spectrum correction stage, it can be found that if the waveform tail caused by the sound and light is not completely eliminated, the blind area will be too large, and the effective wind speed cannot be measured normally at the target distance, such as at a close distance; on the contrary, after the sound and light are eliminated, the blind area becomes smaller, and the effective wind speed can be measured at a close distance. Fig.19 and Fig. 20 As shown, Fig.19 A schematic diagram showing the situation where an abnormal spectrum exists at the target distance, Fig. 20 The figure shows a schematic diagram of the situation where there is no abnormal spectrum at the target distance after the tailing is eliminated.

[0102] In the embodiment of the present application, the laser wind radar effectively shortens the blind area by shortening the pulse width. The mutual delay of two or more stages of acousto-optic modulators in the fiber laser is adjusted accordingly through the FPGA on the hardware control circuit, so that the acousto-optic time of the latter stage is tangent to the falling edge of the light waveform output by the acousto-optic output of the previous stage, thereby eliminating the tail and effectively shortening the blind area.

[0103] It should be understood that although Figure 15-16 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 15-16 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0104] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0105] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A wind laser radar, characterized in that: include: A control device, which sends a first modulation signal and a second modulation signal; A light source module, emitting local oscillator light and signal light, wherein the local oscillator light and the signal light are continuous lasers; A first acousto-optic modulator is loaded with a first modulation signal, receives the signal light, and performs frequency shift modulation and pulse modulation on the signal light based on the first modulation signal to obtain a first modulated signal light; a second acousto-optic modulator, which is loaded with a second modulation signal, receives the first modulated signal light, and performs frequency shift modulation and pulse modulation on the first modulated signal light again based on the second modulation signal to obtain a second modulated signal light; A telescope module receives the second modulated signal light, transmits the second modulated signal light to a target to be measured, and receives and outputs an echo signal reflected by the target to be measured; The detection module receives the echo signal and the local oscillation light, thereby generating a wind speed signal of the target to be detected.

2. The wind laser radar according to claim 1, characterized in that: The control device comprises: A control unit, used for issuing modulation parameter instructions; An FPGA module receives the modulation parameter instruction and generates a first drive modulation signal and a second drive modulation signal based on the modulation parameter instruction; a first acousto-optic driver, receiving the first drive modulation signal and generating a first modulation signal based on the first drive modulation signal; a second acousto-optic driver, receiving the second drive modulation signal and generating a second modulation signal based on the second drive modulation signal; Wherein, according to the pulse timing of the FPGA module, the first modulation signal and the second modulation signal are adjusted so that the first modulation signal and the second modulation signal are synchronized in time.

3. The wind laser radar according to claim 1, characterized in that: Also includes: a first amplification module, disposed between the first acousto-optic modulator and the second acousto-optic modulator, for amplifying the first modulated signal light; The first amplification module also causes a delay to the first modulated signal light; The control device further generates a delay parameter based on the delay, and modulates the first modulation signal and / or the second modulation signal based on the delay parameter, so that the time when the first acousto-optic modulator modulates the signal light is aligned with the time when the second acousto-optic modulator modulates the first modulated signal light.

4. The wind laser radar according to claim 1, characterized in that: Also includes: A second amplification module, disposed between the second acousto-optic modulator and the telescope module, amplifies the second modulated signal light; The second amplifying module is also arranged between the telescope module and the detection module, and amplifies the echo signal output by the telescope module and transmits the amplified echo signal to the detection module.

5. The wind laser radar according to claim 2, characterized in that: The first driving modulation signal is set as an analog signal.

6. The wind laser radar according to claim 2 or 5, characterized in that: The second driving modulation signal is set as a digital signal.

7. The wind laser radar according to claim 1, characterized in that: The first modulated signal light has a first pulse width, and the second modulated signal light has a second pulse width; the first pulse width is greater than or equal to the second pulse width.

8. The wind laser radar according to claim 1, characterized in that: The detection module comprises: A coupler, coupling the echo signal and the local oscillator light, mixing the echo signal and the local oscillator light to obtain a coupled optical signal; The balanced detector receives the coupled optical signal, beats the coupled optical signal, and converts the coupled optical signal after the beat into an electrical signal to obtain a wind speed signal of the target to be measured.

9. A method for measuring wind using a wind laser radar, characterized in that: include: Sending a first modulation signal and a second modulation signal by a control device; Controlling the light source module to emit local oscillator light and signal light, wherein the local oscillator light and the signal light are continuous lasers; Based on the first modulation signal, the signal light is subjected to frequency shift modulation and pulse modulation by a first acousto-optic modulator to obtain a first modulated signal light; Based on the second modulation signal, the first modulation signal light is frequency-shift modulated and pulse-modulated again by a second acousto-optic modulator to obtain a second modulation signal light; the second modulation signal light is incident on the target to be measured via a telescope module, and an echo signal reflected by the target to be measured is received and output via the telescope module; The detection module is controlled to receive the echo signal and the local oscillation light, and to generate a wind speed signal of the target to be measured based on the echo signal and the local oscillation light.

10. The method according to claim 9, characterized in that The second modulated signal light includes a plurality of pulses, and the wind speed signal of the target to be measured is generated based on the echo signal and the local oscillator light, including: The echo signal is mixed with the local oscillator light and then beat again to generate a wind speed signal of the target to be measured; the wind speed signal includes echo signals reflected after the multiple pulses are incident on the target to be measured, and the echo signal includes multiple echo pulse signals; During the reception time of each pulse signal of the plurality of echo pulse signals, the range gate is divided; the range gate division is based on the end face signal emitted by the radar as the starting point, and a range gate is calibrated at every predetermined time interval; Accumulating the multiple echo pulse signals to obtain an accumulated echo pulse signal; filtering the accumulated echo pulse signal to remove noise to obtain a pending wind speed signal; When the pending wind speed signal has no abnormal spectrum, the pending wind speed signal is the wind speed signal of the target to be measured.

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