CN108802425A - A kind of airborne measuring wind speed laser radar system - Google Patents

Abstract

The invention relates to an airborne wind speed measurement laser radar system, which includes a narrow linewidth laser pulse light source module, a radar transceiver optical antenna module and a signal receiving and processing module; the narrow linewidth laser pulse light source module includes a narrow linewidth seed light source, an optical fiber Pre-amplifier, acousto-optic modulator, C-band boost semiconductor optical amplifier and optical fiber main amplifier; the radar transceiver optical antenna module is connected to a narrow linewidth laser pulse light source module, which includes an optical fiber circulator, an optical switch and an optical antenna; the signal receiving The processing module is respectively connected to the narrow-linewidth laser pulse light source module and the radar transceiver optical antenna module; the signal receiving and processing module includes an optical fiber adjustable attenuator, an optical fiber combiner, a balanced photodetector, a signal processing circuit and an embedded computer. The invention has reasonable structural design, stable and reliable use, can provide real-time wind speed data for an airborne air data computer, improves aircraft performance, and ensures flight safety.

Description

An airborne wind speed measurement lidar system

technical field

The invention belongs to the technical field of laser radar detection, and in particular relates to an airborne wind speed measurement laser radar system.

Background technique

If an aircraft encounters a strong airflow during flight, it will pose a great threat to flight safety. Forward atmospheric turbulence and transverse shear wind are one of the main causes of flight accidents. Therefore, the real-time measurement of the atmospheric wind field and airflow changes during the flight of the aircraft is an important task requirement during the flight.

The equipment installed on the aircraft to measure wind speed can be divided into two methods: fixed-point measurement and telemetry. Among the devices for measuring wind speed at fixed points, the traditional on-board wind speed measuring device is the pitot tube. For the flight environment with low air density and low dynamics in the stratosphere, the pressure change caused by the dynamic pressure often cannot be accurately measured. Although the embedded air data system adopted by the new fighter can replace the traditional pitot, the range and accuracy of the pressure sensor cannot meet the requirements for high-altitude and low-speed aircraft. The hot-wire and hot-film anemometers mainly calculate the wind speed by detecting the heat-sensitive temperature dissipation and heat transfer rate exposed to the fluid, but these two kinds of anemometers are limited by the saturation of single-ended input signals, and the range of wind speed measurement is different. High, and temperature measurement requires a certain response time. Although the micro-pressure sensor has the advantages of high sensitivity, light weight, and corrosion resistance, the material itself has temperature drift problems, and it needs to be corrected during continuous operation, and the speed measurement accuracy is not high. Based on the Doppler effect of relative motion, the ultrasonic velocimeter measures the propagation time of ultrasonic waves in a certain direction, and can obtain the propagation speed of downwind or headwind, with high accuracy, but because the sound wave sending and receiving devices have a blocking effect on the wind in the atmosphere, Especially when the wind and the sound wave are sent and received in the same direction, it is easy to cause a large error, and the structure is complicated, which is not easy to realize on the floating platform. The common disadvantage of fixed-point wind speed measurement equipment is that the airflow is easily affected by the shape of the aircraft and changes, so it needs to be calibrated according to the specific shape of the aircraft and the installation location of the equipment.

The typical representative of wind speed telemetry equipment is LiDAR, which has the advantages of high precision, fast response, wide coverage, and measurement results are not affected by the carrier platform. At present, the United States, Japan, France and other countries have mainly reported examples of using airborne lidar to remotely measure the wind speed of aircraft.

Contents of the invention

Aiming at the above-mentioned problems in the background technology, the present invention proposes an airborne wind speed measurement lidar system with reasonable structure design, stable and reliable use, which can provide real-time wind speed data for the airborne air data computer, improve aircraft performance, and ensure flight safety.

Technical scheme of the present invention is as follows:

The above-mentioned airborne wind speed measurement laser radar system includes a narrow linewidth laser pulse light source module, a radar transceiver optical antenna module and a signal receiving and processing module;

The narrow-linewidth laser pulse light source module includes a narrow-linewidth seed light source, an optical fiber preamplifier, an acousto-optic modulator, a C-band boost semiconductor optical amplifier, and an optical fiber main amplifier; the output end of the narrow-linewidth seed light source is connected to the The input end of the optical fiber preamplifier; the output end of the optical fiber preamplifier is connected to the input end of the acousto-optic modulator; the output end of the acousto-optic modulator is connected to the input end of the C-band booster semiconductor optical amplifier; the The output end of the C-band boosting semiconductor optical amplifier is connected to the input end of the optical fiber main amplifier;

The radar transceiver optical antenna module is connected to the narrow linewidth laser pulse light source module, which includes an optical fiber circulator, an optical switch and an optical antenna; the input end of the optical fiber circulator is connected to the output end of the optical fiber main amplifier; the The input end of the optical switch is connected to one of the output ends of the optical fiber circulator through an optical fiber, and the output end of the optical switch is connected to the optical antenna;

The signal receiving and processing module is respectively connected to the narrow-linewidth laser pulse light source module and the radar transceiver optical antenna module; the signal receiving and processing module includes an optical fiber adjustable attenuator, an optical fiber combiner, a balanced photodetector, and a signal processing circuit and an embedded computer; the input end of the optical fiber adjustable attenuator is connected to the other output end of the optical fiber pre-amplifier; the input end of the optical fiber combiner is respectively connected to the other output end of the optical fiber circulator and the The output end of the optical fiber adjustable attenuator; the input end of the balanced photodetector is connected to the output end of the optical fiber combiner; the input end of the signal processing circuit is connected to the output end of the balanced photodetector, so The output end of the signal processing circuit is connected to the embedded computer.

The airborne wind speed measurement lidar system, wherein: the narrow-linewidth seed light source can be any one of a single-frequency narrow-linewidth semiconductor laser outputting continuous laser light in the 1.5 μm band, a DBR/DFB fiber laser, and a solid-state laser; The spectral linewidth of the narrow-linewidth seed light source is less than 15kHz, the polarization state is linear polarization, and the single-mode polarization-maintaining fiber is output, and the output light power is 1-100mW.

The airborne wind speed measurement lidar system, wherein: the optical fiber pre-amplifier adopts a single-mode polarization-maintaining fiber amplifier or a double-clad single-mode polarization-maintaining fiber amplifier, or a single-mode polarization-maintaining fiber amplifier and a double-clad single-layer A multi-stage fiber amplifier composed of a combination of mode-maintaining fiber amplifiers.

The airborne wind speed measurement lidar system, wherein: the rising edge of the modulated pulse of the acousto-optic modulator is less than 100ns, and the frequency is shifted up by 80MHz; the acousto-optic modulator modulates the beam output by the optical fiber pre-amplifier to a full width 500ns pulsed light, pulse repetition frequency 10kHz.

The airborne wind speed measurement laser radar system, wherein: the C-band boosting semiconductor optical amplifier is a polarization-maintaining optical fiber pigtail, which adopts electrical pulse pumping synchronous with the input pulse light; the optical fiber main amplifier is a double-pack layer polarization maintaining fiber amplifier.

The airborne wind speed measurement laser radar system, wherein: the optical switch can adopt any one of a mechanical optical switch with a polarization-maintaining optical fiber pigtail, a mems optical switch, and a magneto-optical switch; the optical switch and the optical fiber ring The optical fiber connection between the devices adopts the method of fusion splicing.

The airborne wind speed measurement lidar system, wherein: the optical antennas are three optical antennas with the same structure and all adopt a single aspheric mirror, the light aperture of the aspheric mirror is 50mm, and the focal length is 180mm; The above optical antennas point to different directions, and the output beams are all focused to 200 meters in front of each other, and the Rayleigh length of the focused light spot is 30 meters.

The airborne wind speed measurement laser radar system, wherein: the signal processing circuit only collects and processes the backscattering signal of the aerosol particles in the Rayleigh length region of the optical antenna focus spot; the sampling frequency of the signal processing circuit is 400MHz, the precision is 14bit.

The airborne wind speed measurement laser radar system, wherein: the signal acquisition and processing flow of the signal processing circuit is as follows:

(1) According to the repetition frequency of the laser pulse is 10KHz, the frequency of the trigger signal for signal acquisition is also 10KHz, and the time interval between two triggers is 100μs;

(2) After receiving the trigger signal, the signal processing circuit performs high-speed digital signal conversion on the analog signal and collects it, and the number of sampling points is 200 points;

(3) After the sampling is finished, fill the sampled data with zeros to 1024 points and perform Fourier transform, obtain the power spectrum and accumulate the power spectrum until the specified number of times is accumulated, otherwise continue to wait for the trigger signal and repeat steps (2)-( 3);

(4) After the accumulation is completed, continue to carry out follow-up processing, adopt the maximum likelihood estimation algorithm to obtain the corresponding frequency to the power spectrum data accumulated before, calculate the corresponding radial wind speed, and the radial wind speed data is output to the embedded computer;

(5) Switch and transmit the optical antenna, and repeat steps (2)-(5).

The airborne wind speed measurement laser radar system, wherein: the sampling point in the correction (2) needs to remove the part of the signal saturation, that is, the data collected each time is delayed for a certain period of time after receiving the trigger signal and focused at 200 meters The 200-point data centered on the data at the place.

Beneficial effect:

The structure design of the airborne wind speed measurement laser radar system of the present invention is reasonable, the semiconductor pulse light amplifier is used to amplify the pulse light, and the modulation depth of the pulse is increased at the same time, so that the problem of pulse leakage can be solved by using only one acousto-optic modulator in the system, reducing The size of the laser can also reduce the cost; at the same time, the pulsed laser is emitted, and the beam is focused to hundreds of meters in front by the optical antenna to form a Rayleigh length area. The system only receives and processes the backscattering of atmospheric aerosols in the laser beam in this area. Signal; take full advantage of the high peak power of the pulsed laser to obtain a strong echo signal, suitable for use in environments with high aerosol density and low density.

Description of drawings

Fig. 1 is the structure schematic diagram of the airborne wind speed measuring lidar system of the present invention;

Fig. 2 is a pattern diagram of the distribution and orientation of optical antennas of the airborne wind speed measurement lidar system of the present invention.

Detailed ways

As shown in FIGS. 1 and 2 , the airborne wind speed measurement laser radar system of the present invention includes a narrow linewidth laser pulse light source module 1 , a radar transceiver optical antenna module 2 and a signal receiving and processing module 3 .

The narrow linewidth laser pulse light source module 1 includes a narrow linewidth seed light source 11 , a fiber preamplifier 12 , an acousto-optic modulator 13 , a C-band boost semiconductor optical amplifier 14 and a fiber main amplifier 15 .

The output end of the narrow-linewidth seed light source 11 is connected to the input end of the fiber preamplifier 12; wherein, the narrow-linewidth seed light source 11 can adopt a single-frequency narrow-linewidth semiconductor laser or a DBR/DFB fiber laser that outputs continuous laser light in the 1.5 μm band and any one of solid-state lasers; the spectral linewidth of the narrow-linewidth seed light source 11 is less than 15 kHz, the polarization state is linear polarization, output by a single-mode polarization-maintaining fiber, and the output optical power is 1-100 mW.

The output end of the optical fiber preamplifier 12 is connected to the input end of the acousto-optic modulator 13; A multi-stage fiber amplifier composed of a polarization fiber amplifier and a double-clad single-mode polarization-maintaining fiber amplifier.

The output end of the AOM 13 is connected to the input end of the C-band booster semiconductor optical amplifier 14; wherein, the modulation pulse rising edge of the AOM 13 is less than 100 ns, and the frequency is shifted up by 80 MHz, and it outputs the optical fiber preamplifier 12 The beam is modulated into a pulsed light with a full width of 500ns and a pulse repetition frequency of 10kHz.

The output end of the C-band boosting semiconductor optical amplifier 14 is connected to the input end of the optical fiber main amplifier 15; wherein, the C-band boosting semiconductor optical amplifier 14 is a polarization-maintaining optical fiber pigtail, and adopts an electric pulse pump synchronous with the input pulse light Pu.

The optical fiber main amplifier 15 is a double-clad polarization-maintaining optical fiber amplifier.

Wherein, the optical fiber preamplifier 12 receives the linearly polarized continuous laser light output by the narrow linewidth seed light source 11, and the optical fiber preamplifier 12 transmits the light beam to the acousto-optic modulator 13, and the acousto-optic modulator 13 outputs the optical fiber preamplifier 12 The light beam is modulated into pulsed light, and the acousto-optic modulator 13 transmits the modulated pulsed light to the C-band boosting semiconductor optical amplifier 14, and the C-band boosting semiconductor optical amplifier 14 further amplifies and modulates the optical pulse. The semiconductor optical amplifier 14 transmits the further amplified and modulated optical pulses to the optical fiber main amplifier 15, and the optical fiber main amplifier 15 amplifies and outputs the pulse optical power.

The radar transceiver optical antenna module 2 is connected to the narrow linewidth laser pulse light source module 1 , which includes a fiber optic circulator 21 , an optical switch 22 and an optical antenna 23 .

The input end of the optical fiber circulator 21 is connected to the output end of the optical fiber main amplifier 15 .

The optical switch 22 has an input end and a plurality of output ends, the input end of the optical switch 22 is connected to one of the output ends of the optical fiber circulator 21 through an optical fiber, and the output end of the optical switch 22 is connected to three optical antennas 23; wherein, the optical switch 22 The optical switch 22 can be any one of a mechanical optical switch with a polarization-maintaining fiber pigtail, a mems optical switch, and a magneto-optical switch; the optical switch 22 can switch the input beam to any output through electrical signal control, and the laser radar During work, the light beams are sequentially switched from each output end of the optical switch 22 to be emitted through the corresponding optical antenna 23, and then go round and round; at the same time, the optical fiber connection between the optical switch 22 and the optical fiber circulator 21 adopts a fusion splicing method to avoid When the connector is used, the reflected light from the end face of the fiber interferes with the local oscillator light.

The three optical antennas 23 have the same structure, and all adopt a single aspheric mirror, the aspheric mirror has a light aperture of 50mm and a focal length of 180mm; wherein, the three optical antennas 23 point to different directions, and the output beams are all focused to 200 meters ahead of each other. The Rayleigh length of the spot is 30 meters.

The signal receiving and processing module 3 is respectively connected to the narrow-linewidth laser pulse light source module 1 and the radar transceiver optical antenna module 2, and the signal receiving and processing module 3 includes an optical fiber adjustable attenuator 31, an optical fiber combiner 32, a balanced photodetector 33, Signal processing circuit 34 and embedded computer 35 .

The optical fiber tunable attenuator 31 is used to adjust the output local oscillator optical power of the optical fiber preamplifier 12 , and its input end is connected to the other output end of the optical fiber preamplifier 12 of the narrow linewidth laser pulse source module 1 .

The fiber combiner 32 is a 2×2 fiber combiner, and its input end is respectively connected to the other output end of the optical fiber circulator 21 of the radar transceiver optical antenna module 2 and the output end of the optical fiber adjustable attenuator 31 .

The input end of the balanced photodetector 33 is connected to the two output ends of the fiber combiner 32 .

The input end of this signal processing circuit 34 is connected to the output end of balanced photodetector 33, and the output end of this signal processing circuit 34 is connected to embedded computer 35; Wherein, this signal processing circuit 34 only collects and processes three optical antennas 23 focusing The backscattering signal of the aerosol particles in the area of Rayleigh length of the light spot; the sampling frequency of the signal processing circuit 34 is 400MHz, the precision is 14bit, and the signal is processed by FPGA (Field Programmable Gate Array) programming.

Wherein, for the echo signal received by each optical antenna 23, according to the pulse width 500ns, it can be determined that the single signal sampling time of the signal processing circuit 34 is 500ns, and according to the sampling frequency is 400MHz, it can be determined that the number of single sampling points is 200 points; The sub-sampled 200-point data is filled with zeros to 1024 points, window function is added, fast Fourier transform is performed, and then the power spectrum is calculated. The spectrum resolution after FFT transformation is less than 0.4MHz, and the corresponding speed accuracy is less than 0.3m/s; due to the The power spectrum accumulation algorithm can improve the accuracy of speed measurement. The signal power spectrum measured by a single optical antenna 23 is accumulated 5000 times, and the final speed accuracy is less than 0.1m/s.

The signal acquisition and processing flow of the signal processing circuit 34 is as follows:

(1) According to the laser pulse repetition frequency of 10KHz (or 5kHz, 8kHz, etc.), the frequency of the trigger signal for signal acquisition is also 10KHz, and the time interval between two triggers is 100μs;

(2) After receiving the trigger signal, the signal processing circuit 34 converts the analog signal to a high-speed digital signal and collects it, and the number of sampling points is 200;

(3) After the sampling is finished, fill the sampled data with zeros to 1024 points and perform Fourier transform; calculate the power spectrum and accumulate the power spectrum. If the number of accumulated times reaches the specified 5000 times, proceed to the next step, otherwise continue to wait for the trigger signal, repeat steps (2)-(3);

(4) After the accumulation is completed, continue to carry out follow-up processing, adopt the maximum likelihood estimation algorithm to obtain the corresponding frequency to the power spectrum data accumulated before, calculate the corresponding radial wind speed, and the radial wind speed data is output to the embedded computer 35;

(5) Switch the transmitting optical antenna 23, and repeat steps (2)-(5).

Wherein, due to the reflection of the end face of the optical fiber head and the reflection of the optical antenna 23 mirrors, the optical signal will cause the balance photodetector 33 to saturate, so the sampling point used for calculation will remove the part of the signal saturation, so the data collected each time is obtained from 200-point data that is delayed for a certain time after the trigger signal and centered on the data at the 200-meter focal point.

As shown in Figure 2, take the direction of the nose of the aircraft as the direction of the +X axis, and the direction of the belly of the aircraft as the direction of the +Z axis, and establish a right-handed coordinate system; The included angles are all 15°, pointing to different directions.

In the case of the arrangement of optical antennas as shown in Figure 2, the embedded computer 35 respectively receives the radial wind velocities in the directions directed by the three optical antennas 23 sent by the signal processing circuit 34, and solves the respective radial wind velocities on the body coordinate axis Scalar summation is carried out on each coordinate axis to obtain the respective wind speed components in the X, Y, and Z axis directions of the aircraft body coordinates.

The working principle of the present invention is as follows:

The low-power laser output by the narrow-linewidth seed light source 11 is amplified by the optical fiber pre-amplifier 12, and the optical fiber pre-amplifier 12 is divided into two outputs, one outputting light with a small part of power as a local oscillator signal, and the other outputting most of the power of light being amplified by the acoustic The optical modulator 13 modulates into pulsed light, and at the same time generates a frequency shift of tens of megahertz. The pulsed light is amplified by the C-band booster semiconductor optical amplifier 14, and the pulse modulation depth is increased at the same time. Finally, the laser is amplified by the optical fiber main amplifier 15 and then output The output light beam is incident from one input port of the optical fiber circulator 21, emerges through two output ports, and then switches the direction of the light beam through the optical switch 22 and emits it through three differently directed optical antennas 23; each optical antenna 23 emits a focused beam to the front To measure the light beam, each optical antenna 23 focuses the emitted light beam at the same distance, and the distance is hundreds of meters; the Doppler frequency-shifted echo signal is generated by the aerosol in the atmosphere scattering the laser light in the Rayleigh length region where the light beam is focused. The optical path returns, and the echo signal is output from the optical fiber circulator 21; the echo signal and the local oscillator light are combined through the 2×2 optical fiber combiner 32 and then incident on the balanced photodetector 33 to generate a heterodyne signal, which is sent into the signal The processing circuit 34 extracts the Doppler frequency to obtain the radial velocity information of each beam; after measuring the radial velocity of each beam respectively, the embedded computer 35 calculates the wind field information through the wind field inversion algorithm.

The invention has reasonable structural design, stable and reliable use, can provide real-time wind speed data for an airborne air data computer, improves aircraft performance, and ensures flight safety.

The above technical scheme uses pulsed light to measure the backscattering signal of aerosol in the air, and measures the radial wind speed in each direction through the different directions of the multi-optical antenna. After the wind field inversion, an airborne wind speed measurement radar can be realized, which can be applied to Aircraft true speed measurement and other application fields.

According to the above-mentioned embodiments, the present invention can be well realized. It is worth noting that, based on the premise of the above-mentioned design principles, in order to solve the same technical problem, even some insubstantial changes or modifications are made on the basis of the structure disclosed in the present invention, such as increasing the number of optical antennas, changing the optical The essence of the adopted technical solution is still the same as that of the present invention for changes such as the aperture of the antenna, different focusing distances, etc., so it should also be within the protection scope of the present invention.

Claims (10)

1. a kind of airborne measuring wind speed laser radar system, it is characterised in that：The radar system includes narrow-linewidth laser pulse Light source module, radar transmit-receive optical antenna module and signal receiving processing module；

The narrow-linewidth laser light-pulse generator module includes narrow linewidth seed light source, optical fiber prime amplifier, acousto-optic modulator, C waves Section boosting semiconductor optical amplifier and optical fiber main amplifier；The output end of the narrow linewidth seed light source connects the predispersed fiber and puts The input terminal of big device；The output end of the optical fiber prime amplifier connects the input terminal of the acousto-optic modulator；The acousto-optic modulation The output end of device connects the input terminal of the C-band boosting semiconductor optical amplifier；The C-band boosting semiconductor optical amplifier Output end connect the input terminal of the optical fiber main amplifier；

The radar transmit-receive optical antenna module connects the narrow-linewidth laser light-pulse generator module comprising optical fiber circulator, Photoswitch and optical antenna；The input terminal of the optical fiber circulator connects the output end of the optical fiber main amplifier；The light is opened The input terminal of pass connects the one of output end of the optical fiber circulator by optical fiber, described in the output end connection of the photoswitch Optical antenna；

The signal receiving processing module is separately connected the narrow-linewidth laser light-pulse generator module and radar transmit-receive optical antenna Module；The signal receiving processing module includes optical fiber adjustable attenuator, optical-fiber bundling device, balances photodetector, at signal Manage circuit and embedded computer；The input terminal of the optical fiber adjustable attenuator connects another output of the optical fiber prime amplifier End；The input terminal of the optical-fiber bundling device is separately connected another output end of the optical fiber circulator and the optical fiber adjustable damping The output end of device；The input terminal of the balance photodetector connects the output end of the optical-fiber bundling device；The signal processing The input terminal of circuit connects the output end of the balance photodetector, and the output end of the signal processing circuit is connected to described Embedded computer.

2. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The narrow linewidth seed light source The single mode narrow linewidth semiconductor laser, DBR/DFB optical fiber lasers, solid that 1.5 mu m wavebands output continuous laser can be used swash Any one in light device；The spectral line width of the narrow linewidth seed light source is less than 15kHz, and polarization state is linear polarization, and single mode is protected Inclined optical fiber output, 1~100mW of Output optical power.

3. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The optical fiber prime amplifier is adopted With single-mode polarization maintaining fiber amplifier or double clad single-mode polarization maintaining fiber amplifier, then using by single-mode polarization maintaining fiber amplifier The multi-stage fiber amplifier constituted with double clad single-mode polarization maintaining fiber amplifier combination.

4. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The tune of the acousto-optic modulator Rising edge of a pulse processed is less than 100ns, upper shift frequency 80MHz；The light beam that the acousto-optic modulator exports the optical fiber prime amplifier It is modulated to the pulsed light of overall with 500ns, pulse recurrence frequency 10kHz.

5. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The C-band boosting is partly led Body image intensifer is band polarization maintaining fiber pigtail, uses and is pumped with the electric pulse of input pulse phototiming；The main amplification of optical fiber Device is double clad polarization maintaining optical fibre amplifier.

6. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：Band can be used in the photoswitch Any one in the mechanical optical switch of polarization maintaining fiber pigtail, mems photoswitches, magneto-optic shutter；The photoswitch and fiber optic loop Optical fiber between shape device connects by the way of welding.

7. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The optical antenna is three The identical optical antenna of structure and it is all made of monolithic aspherical mirror, the clear aperture of the aspherical mirror is 50mm, and focal length is 180mm；Three optical antennas are directed toward different orientation, and output beam all focuses at respectively 200 meters of front, focal beam spot Rayleigh range be 30 meters.

8. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The signal processing circuit is only Acquire and handle the backscatter signal of particulate in the optical antenna focal beam spot Rayleigh range region；The signal The sample frequency of processing circuit is 400MHz, precision 14bit.

9. airborne measuring wind speed laser radar system as described in claim 1, it is characterised in that：The signal processing circuit Signal acquisition process flow is as follows：

(1) it is 10KHz according to the repetition rate of laser pulse it is found that the frequency of trigger signal for carrying out signal acquisition is similarly 10KHz, the time interval between triggering twice are 100 μ s；

(2) after receiving trigger signal, the signal processing circuit is adopted after analog signal is carried out high-speed digital signal conversion Collection, sampling number are 200 points；

(3) it after sampling, by sampled data zero padding to Fourier transform is done after 1024 points, seeks power spectrum and carries out power spectrum It is cumulative, until being added to stipulated number, trigger signal is otherwise continued waiting for, step (2)-(3) are repeated；

(4) it adds up and continues subsequent processing after completing, maximum likelihood estimation algorithm is used to preceding cumulative power spectrum data Corresponding frequency is obtained, corresponding radial wind speed is calculated, radial air speed data is exported to the embedded computer；

(5) switching emits the optical antenna, repeats step (2)-(5).

10. airborne measuring wind speed laser radar system as claimed in claim 9, it is characterised in that：Sampling in the correction (2) Point to remove signal saturation part, i.e., the data acquired every time be after receiving trigger signal postpone certain time and with 200 point datas of 200 meters of focal spot data grid technologies.