Low-altitude wind phased array acoustic detection radar device

Abstract

The invention discloses a low-altitude wind phased array acoustic detection radar device which comprises a phased array antenna array, a transmitting unit, a receiving unit, a beam control unit and a data processing unit. The phased-array antenna array comprises an equidistant square area array formed by a plurality of receiving / transmitting reversible transducers, the transducers in the same row have the same working frequency, and the transducers in different rows have different working frequencies; the transmitting unit is used for outputting a transmitting signal to the phased-array antenna array; the receiving unit is used for receiving an echo signal of the phased-array antenna array; the beam control unit comprises a transmit-receive switching device which is used for controlling transmit-receive switching of the phased-array antenna array. And the data processing unit is used for receiving and intelligently processing the echo signal. The method has the advantages that a better intelligent noise suppression effect is achieved, and more accurate weather detection information can be obtained.

Description

Technical Field

[0001] The present application relates to the technical field of meteorological detection, and in particular to a low-altitude wind phased array acoustic detection radar device. Background Art

[0002] Traditional low-altitude meteorological detection mainly uses wind towers for measurement. It is necessary to build a 100m or even 200m high iron tower and install meteorological detection sensors on the tower to achieve low-altitude meteorological detection. This detection method has complex equipment construction, high cost, poor maintenance, and cannot be used in a mobile manner, which has great limitations in applicability.

[0003] As an emerging wind measurement technology, acoustic radar wind measurement has been vigorously promoted and applied due to its wide detection range, high reliability, ease of use, low cost, and high cost performance. By directional emission of strong sound pulses of a certain frequency, receiving sound scattered echoes, analyzing the intensity of sound scattered echoes, and comparing the difference in the frequency of the emitted sound waves and the sound scattered echoes, the acoustic radar can calculate the changes in wind direction, wind speed, and vertical airflow over time and height.

[0004] Due to its own technical principles and application scenarios, acoustic radar will inevitably generate noise, and the echo signal contains many types of noise and strong noise signals, which will have an adverse effect on subsequent signal processing. At present, the noise suppression of acoustic radar includes physical noise reduction in the antenna device and noise reduction through filters and software at the signal receiving end. However, due to the complexity of the echo signal noise, it is still difficult to achieve a good noise reduction effect, which has an adverse effect on weather forecasting, especially wind and cloud measurement. Summary of the invention

[0005] The present application provides a low-altitude wind phased array acoustic detection radar device, which has the advantage of having a better noise suppression effect and is conducive to obtaining more accurate weather detection information.

[0006] The above-mentioned object of the present application is achieved through the following technical scheme: a low-altitude wind phased array acoustic detection radar device, comprising: A phased array antenna array, wherein the phased array antenna array comprises a plurality of reversible transceiver transducers forming an equidistant square array, wherein transducers in the same row have the same operating frequency, and transducers in different rows have different operating frequencies; A transmitting unit, the transmitting unit is used to output a transmitting signal to the phased array antenna array; A receiving unit, the receiving unit is used to receive an echo signal of a phased array antenna array; A beam control unit, the beam control unit comprising a transceiver switching device, the transceiver switching device is used to control the transceiver switching of the phased array antenna array; and a data processing unit for receiving and intelligently processing echo signals.

[0007] Furthermore, in the phased array antenna array, the operating frequency of each row of transducers gradually increases.

[0008] Furthermore, in the phased array antenna array, the operating frequency of each row of transducers is equidistantly distributed, and specifically the operating frequency of each row of transducers is:

[0009] in, is the operating frequency of the i-th row transducer, To set the base frequency, is the operating frequency difference between adjacent rows of transducers.

[0010] Furthermore, the transmitting unit has several paths, which are respectively used to transmit signals to different rows of transducers, and the output signal frequency of each path is adapted to the operating frequency of each row of transducers.

[0011] Furthermore, the receiving unit has several paths, which are respectively used to receive echo signals from transducers in different rows, and each path includes a transceiver switch, a transformer, a low noise amplifier, a filter and a programmable gain amplifier.

[0012] Furthermore, the transceiver switching device includes a plurality of solid-state electronic relays and a drive circuit connected in parallel. The drive circuit receives a transceiver switching control signal sent by a host computer and controls the action of the solid-state electronic relay. The solid-state electronic relay is used to control the connection between the phased array antenna array and the receiving unit or the transmitting unit.

[0013] Furthermore, the data processing unit includes a noise processing unit, and the noise processing unit is used to intelligently suppress the noise in the echo signal, the steps are: Perform fast Fourier transform on the obtained echo signals to obtain ,in, represents the fast Fourier transform result of the j-th echo signal; Compare the transformed echo signals of several paths, mark the frequency signals whose amplitude differences among the echo signals are within the preset value as noise signals and delete them to obtain , It represents the result after removing the noise from the j-th echo signal.

[0014] Furthermore, any n-way signal In the formula, n is a positive integer greater than or equal to 2 and less than the number of rows of the phased array antenna. For a signal of any frequency, if the amplitude ratio difference is less than τ, where τ is a preset threshold, the frequency signal is judged to be a noise signal.

[0015] Furthermore, the acoustic radar device also includes an antenna heating device, which includes an automatic temperature controller, a temperature sensor and a heating cable. The heating cable is coiled at the bottom of the transducer. The temperature sensor is arranged in the phased array antenna array or next to the phased array antenna array to detect the temperature of the phased array antenna array. The automatic temperature controller is used to control the heating cable to be energized when the temperature of the phased array antenna array is lower than a set value.

[0016] Furthermore, the acoustic radar device also includes an antenna cover, the opening of the antenna cover gradually increases, the phased array antenna array is installed at the bottom of the antenna cover, and a sound-absorbing sponge or a sound-absorbing panel is provided in the antenna cover; a protective net is provided at the opening of the antenna cover.

[0017] Furthermore, the acoustic radar device also includes an ultrasonic wind measuring device, an ultrasonic wind measuring instrument and a manual lifting rod, the ultrasonic wind measuring instrument includes a transmitting surface and a reflecting surface arranged relatively to each other, the transmitting surface and the reflecting surface are both arc-shaped, and four ultrasonic probes are arranged on the transmitting surface, and the ultrasonic probes are ultrasonic probes with integrated transmission and reception.

[0018] Furthermore, the manual lifting rod includes an external fixed rod, an internal telescopic rod, a fixed base, a clamp fixing seat, a locking sleeve, a live buckle, a limit pin, and an internal guide sleeve, wherein the fixed base and the clamp fixing seat are arranged on a fixed object, the external fixed rod is installed on the fixed base and the clamp fixing seat to achieve fixation, the internal telescopic rod is arranged in the external fixed rod and can be telescopically moved, the locking sleeve is arranged at the end of the external fixed rod, and has a live buckle thereon for adjusting the locking degree of the locking sleeve, when locking, the internal telescopic rod is clamped and fixed by the external fixed rod, and when not locked, the internal telescopic rod can be manually telescoped and extended to adjust the extension height of the internal telescopic rod.

[0019] To sum up, the beneficial effects of the present application are: the present application obtains echo detection signals of different frequencies through transducers of different operating frequencies, and then compares the same parts in different echo detection signals to identify noise that is difficult to filter out, thereby improving the denoising effect, which is conducive to obtaining more accurate meteorological detection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a low-altitude wind sound detection radar in a specific embodiment of the present application; Figure 2 is a schematic diagram of a radome in a specific embodiment of the present application; Figure 3 is a schematic diagram of a phased array antenna array in a specific embodiment of the present application; Figure 4 is a schematic diagram of an antenna heating device in a specific embodiment of the present application; Figure 5It is a schematic diagram of the emitting surface and reflecting surface of an ultrasonic anemometer in a specific embodiment of the present application; Figure 6 This is a schematic diagram of ultrasonic signal transmission of an ultrasonic anemometer in a specific embodiment of the present application; Figure 7 It is a schematic diagram of the principle of an ultrasonic anemometer in a specific embodiment of the present application; Figure 8 is a schematic diagram of the principle of ultrasonic wind measurement in a specific embodiment of the present application; Fig. 9 is a schematic diagram of a sound host in a specific embodiment of the present application; Fig.10 This is a schematic diagram of the principle of a transceiver switching device in a specific embodiment of the present application; Fig.11 It is a schematic diagram of the acoustic detection radar beam; Fig.12 It is a three-dimensional diagram of the simulation of the "west beam" array in a specific embodiment of the present application; Fig.13 is the normalized plane lobe of the beam in a specific embodiment of the present application Figure 1 ; Fig.14 is the normalized plane lobe of the beam in a specific embodiment of the present application Figure 2 ; Fig.15 This is a schematic diagram of the principle of a receiving unit in a specific embodiment of the present application; Fig.16 It is a schematic diagram of the principle of the sonar host in a specific embodiment of the present application; Fig.17 This is a functional block diagram of a data processing module in a specific embodiment of the present application; Fig.18 is a schematic diagram of data processing software in a specific embodiment of the present application; Fig.19 It is a flowchart of data processing software in a specific embodiment of the present application. DETAILED DESCRIPTION

[0021] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0022] Embodiment 1: A low-altitude wind phased array acoustic detection radar device includes a phased array antenna array, a transmitting unit, a receiving unit, a beam control unit and a data processing unit.

[0023] refer to Figure 3The phased array antenna array includes a plurality of reversible transceivers forming an equally spaced square array, wherein the transducers in the same row have the same operating frequency, and the transducers in different rows have different operating frequencies. As an example, in this embodiment, the phased array antenna array includes 64 reversible transceivers, and the 64 transducers are evenly arranged in an "8×8" pattern. The transducer size is ø24×20mm, and the spacing is 30mm, forming a square array of 234mm×234mm.

[0024] In the phased array antenna array, the operating frequency of each row of transducers gradually increases.

[0025] Particularly, in this embodiment, in the phased array antenna array, the operating frequency of each row of transducers is equidistantly distributed, and specifically the operating frequency of each row of transducers is:

[0026] in, is the operating frequency of the i-th row transducer, To set the base frequency, is the operating frequency difference between adjacent rows of transducers.

[0027] As an example, for an 8×8 phased array antenna array, is 20KHz, is 5KHz.

[0028] The transmitting unit is used to output a transmitting signal to the phased array antenna array; the transmitting unit has a plurality of paths, which are respectively used to transmit signals to transducers in different rows, and the output signal frequency of each path is adapted to the operating frequency of each row of transducers.

[0029] refer to Fig.15 , the receiving unit is used to receive the echo signal of the phased array antenna array; the receiving unit has several paths, which are used to receive the echo signals of different rows of transducers respectively, and each path includes a transceiver switch, a transformer, a low noise amplifier, a filter and a programmable gain amplifier. Since the echo signal is relatively weak, a low noise, low temperature drift operational amplifier is used to amplify the signal with a certain gain. In order to obtain the best impedance matching with the receiving transducer, a transformer is used for impedance transformation. Since the environmental noise contains a strong interference signal, in order to prevent the interference signal from generating unnecessary multiple harmonics after a high gain amplification, a differential amplifier is introduced at the rear end of the transformer, and the gain of the preamplifier circuit is controlled at about 60dB. For the signal after preamplification, it first passes through a bandpass filter, mainly according to the bandwidth of the transmitted signal, the echo signal is bandpass filtered to filter out the interference noise, and then according to the size of the signal, different gains of amplification and filtering are performed, and the received signal is sent to the data processing module, and the receiving gain is greater than 100dB.

[0030] For an 8×8 phased array antenna array, both the transmitting unit and the receiving unit have 8 channels, corresponding to 8 rows of transducers respectively.

[0031] refer to Fig.10 , the beam control unit includes a transceiver switching device, which is used to control the transceiver switching of the phased array antenna array; the transceiver switching device includes a number of parallel solid-state electronic relays and a drive circuit, the drive circuit receives the transceiver switching control signal sent by the host computer and controls the action of the solid-state electronic relay, and the solid-state electronic relay is used to control the connection between the phased array antenna array and the receiving unit or the transmitting unit. It can be understood that for an 8×8 phased array antenna array, the number of solid-state electronic relays is 8, 16, or 64, and the solid-state electronic relay is used to switch between the receiving unit and the transmitting unit.

[0032] The data processing unit is used to receive and intelligently process the echo signal. The data processing unit includes a noise processing unit, which is used to intelligently suppress the noise in the echo signal, and the steps are: Perform fast Fourier transform on the obtained echo signals to obtain ,in, represents the fast Fourier transform result of the j-th echo signal; Compare the transformed echo signals of several paths, mark the frequency signals whose amplitude differences among the echo signals are within the preset value as noise signals and delete them to obtain , It represents the result after removing the noise from the j-th echo signal.

[0033] The part of the noise whose frequency is within the filter bandpass is not easily removed by the filter, and the noise will be received approximately equally by the transducers in each row. Therefore, by comparing the transformed echo signals of several paths, the signal frequency with equal or close amplitude is the noise.

[0034] Furthermore, any n-way signal In the formula, n is a positive integer greater than or equal to 2 and less than the number of rows of the phased array antenna. For a signal of any frequency, if the amplitude ratio difference is less than τ, where τ is a preset threshold, the frequency signal is judged to be a noise signal.

[0035] The part of the noise that is close to the operating frequency of the transducer still exists in the previous processing step. By comparing n signals, where n is a positive integer greater than or equal to 2 and less than the number of rows of the phased array antenna array, for an 8×8 phased array antenna array, n is any positive integer between 2 and 7, the noise close to the operating frequency of a certain transducer can be found.

[0036] The denoised data is then output to a separate host computer for data analysis to obtain meteorological data, which is a prior art and will not be described in detail here.

[0037] The present application uses a filter to filter out the noise outside the passband, and then uses the scheme of the present application to remove the noise within the passband and the noise close to the transducer frequency, thereby achieving a better denoising effect.

[0038] Embodiment 2: A low altitude wind phased array acoustic detection radar device, referring to Figure 1 , including a sonar host, an ultrasonic wind measuring device and a phased array acoustic antenna device.

[0039] The phased array acoustic antenna device includes a radome, a protective net, and a phased array antenna array, and the phased array antenna array is the same as the phased array antenna array of the first embodiment. Figure 2 , the opening of the radome gradually increases and is horn-shaped. The phased array antenna array is installed at the bottom of the radome. Sound-absorbing sponges and sound-absorbing panels are provided in the radome to remove noise generated by the near environment. The radome is made of two-component polyurethane PU material, and the transducer array is formed by nylon glass fiber through a mold. The protective net is arranged at the top of the radome (that is, at its opening) to protect the sonar antenna and prevent falling objects from damaging the sonar array antenna. The protective net is made of metal, especially if rust-proof aluminum is selected as the material of the protective net, and then three-proof treatment is performed to ensure that the protective net can work reliably outdoors for a long time. As an example, the longitudinal and lateral spacing of the protective net is 85mm.

[0040] refer to Figure 4 The low-altitude wind sound detection radar also includes an antenna heating device, which includes an automatic temperature controller, a temperature sensor and a heating cable. The heating cable is coiled at the bottom of the transducer. The temperature sensor is arranged in the phased array antenna array or next to the phased array antenna array to detect the temperature of the phased array antenna array. The automatic temperature controller is used to control the heating cable to be powered on when the temperature of the phased array antenna array is lower than the set value. When the power switch of the antenna heating device is closed, the automatic temperature controller starts to work. Heating is started when the outside temperature is detected to be lower than 0º; when the temperature rises to 20º, heating is stopped. When it snows in winter, there may be snow inside the antenna. The antenna heating device can be used for defrosting and snow.

[0041] The ultrasonic wind measuring device is used to complete the detection of ground wind and output the detection results to the sonar host. The ultrasonic wind measuring device consists of an ultrasonic anemometer and a manual lifting rod. A shell is set outside the ultrasonic anemometer, and the shell material is aluminum alloy; it is anodized and then painted. In this embodiment, the outer dimensions of the ultrasonic anemometer and the shell are: diameter 64mm, height 68mm, weight 1kg, and a manual lifting rod.

[0042] The manual lifting rod includes an outer fixed rod, an inner telescopic rod, a fixed base, a clamp fixing seat, a locking sleeve, a snap lock, a limit pin, and an internal guide sleeve, wherein the fixed base and the clamp fixing seat are arranged on a fixed object, which can be a wall, a steel frame, a vehicle, etc. according to different application scenarios of the sodar. The fixed base is welded from high-strength stainless steel, and the outer fixed rod is installed on the fixed base and the clamp fixing seat to achieve fixation. One end of the outer fixed rod is fixedly connected or rotatably connected to the fixed base, and the other end is fixed by the clamp fixing seat. The inner telescopic rod is arranged inside the outer top rod and can be telescopically moved. The locking sleeve is arranged at the end of the outer fixed rod, and there is a snap lock on it. The snap lock can be spiral or wedge-shaped, which are both existing technical solutions, and are used to adjust the locking progress of the locking sleeve. When locked, the inner telescopic rod is held tightly by the inner telescopic rod and fixed. When not locked, the inner telescopic rod can be manually extended and retracted to adjust the extension height of the inner telescopic rod. The internal guide sleeve is arranged in the outer fixing rod, and is used to contact with the inner telescopic rod and reduce friction. The internal guide sleeve is made of polytetrafluoroethylene, which is wear-resistant and not easy to deform. Its main function is to guide and prevent the telescopic rod from becoming unstable due to excessive height when it is extended. The limit pin is arranged on the side wall of the outer fixing rod and extends into the long slide groove arranged on the side wall of the inner telescopic rod, which has limited the extension and contraction of the inner telescopic rod. The limit pin reaches the upper and lower dead points of the long groove to prevent the inner telescopic rod from retracting into the outer fixing rod and coming out. The outer fixing rod is made of cold-drawn stainless steel pipe, which has the characteristics of high strength and not easy to deform; the inner telescopic rod is made of cold-drawn aluminum pipe, which has high strength and light weight, and is convenient for manual extension and lowering. At the same time, when it is extended and fixed, it will not slide down due to excessive weight. The ultrasonic anemometer is connected through the threaded hole at the top of the inner telescopic rod and locked by the matching nut. As an example, the maximum extension height of the manual lifting rod is 300mm, which provides the necessary working height for the ultrasonic anemometer.

[0043] The ultrasonic anemometer includes an upper plate and a lower plate, the upper plate and the lower plate have a gap, and are connected by a central column. The ultrasonic anemometer is generally hourglass-shaped. The ultrasonic anemometer includes a transmitting surface and a reflecting surface that are relatively arranged. The transmitting surface and the reflecting surface are both arc-shaped. Four ultrasonic probes are arranged on the transmitting surface. The ultrasonic probes are transceiver-integrated ultrasonic probes.

[0044] refer to Figure 5-7According to the principle of ultrasonic wind measurement, the wind speed and wind direction are calculated by the time or frequency difference between the transmitting end transmitting the ultrasonic wave and the receiving end receiving the ultrasonic wave. If the distance between the transmitting end and the receiving end is short, the path of the transmitting signal is short, and the receiving end may not avoid the aftershock signal of the transmitting signal and cannot normally receive the transmitting signal, thereby causing the calculation error of the ultrasonic anemometer. Therefore, the transmitting signal of the ultrasonic anemometer needs to pass through a sufficiently long path to enlarge the time or frequency difference between the transmitting end transmitting the ultrasonic wave and the receiving end receiving the ultrasonic wave. In order to reduce the size of the ultrasonic anemometer, in the ultrasonic anemometer of this embodiment, four ultrasonic probes are selected to be installed on the transmitting surface, and the reflecting surface is arranged opposite to the transmitting surface and separated by a preset distance. Both the transmitting surface and the reflecting surface are curved surfaces. The signal emitted from the ultrasonic probe is received by the receiving probe after multiple reflections on the transmitting surface and the reflecting surface. Even if the preset distance between the transmitting surface and the reflecting surface is very small, the reflected signal is received by another ultrasonic probe after multiple reflections. Therefore, the reflection path of the reflected signal is long, thereby avoiding the influence of the aftershock signal of the transmitting signal. On the one hand, the calculation accuracy of the ultrasonic anemometer can be improved, and on the other hand, the preset distance between the emitting surface and the reflecting surface can be very small, thereby reducing the volume of the ultrasonic anemometer.

[0045] The beam opening angle of the transmitting signal of the selected ultrasonic probe is greater than 60°. On the one hand, it can ensure that the transmitting signal is reflected multiple times in the cavity of the transmitting shell and the reflecting shell. The longer the reflection path of the reflected signal is, the further the preset distance between the reflecting shell and the transmitting shell can be shortened. On the other hand, each ultrasonic transmitting signal is reflected to both sides after reaching the reflecting surface. Since multiple ultrasonic probes are evenly distributed on the transmitting surface, the transmitting signal of each ultrasonic probe can be received by its two adjacent ultrasonic probes at the same time. By acquiring more ultrasonic transmission and reception data, the accuracy of wind speed measurement of the ultrasonic anemometer is improved, and the measurement performance of the ultrasonic anemometer is improved.

[0046] In order to measure the wind speed and direction in each direction, the ultrasonic anemometer uses two pairs of probes to measure the wind speed in two horizontal directions at the same time in the directions perpendicular to each other on the horizontal plane, and then calculates the wind direction and wind speed on the horizontal plane by orthogonal synthesis, and transmits it to the sonar host through the serial port for fusion with the sonar data and sends it to the upper system. The schematic diagram of the ultrasonic anemometer is shown in the figure below. Figure 7 shown.

[0047] refer to Figure 8 , the ground wind is measured by an ultrasonic anemometer. Ultrasonic wave is the propagation process of mechanical vibration in the medium. If two pairs of ultrasonic probes are placed parallel along the X direction in the wind field, T1 and T2 are for transmission, R1 and R2 are for reception, and the distance between them is L.

[0048] Assume that the speed of sound in the air in the absence of wind is C, the component of the wind speed V along the X direction is Vx, and the component along the plane orthogonal to the X axis is Vy. The propagation time from T1 to R1 and from T2 to R2 in the positive and negative directions are: (1) (2) If the distance L is much larger than the wavelength of the sound wave, the sound wave can be simplified as a plane wave. In this case, the propagation time of the sound wave in the X direction is only related to the wind speed in the X direction. Then (1) and (2) can be simplified as: (3) (4) From equation (3) and equation (4), we can get:

[0049] Therefore, as long as the ultrasonic propagation time from the application of the excitation pulse to the transmitting probe to the reception of the first pulse by the receiving probe is measured under the conditions of downwind and headwind in a certain direction, the wind speed in that direction can be calculated. If the wind speed components in two different directions are measured, the total wind speed and wind direction can be calculated according to the principle of vector synthesis. Due to the symmetrical measurement method, the measurement result is independent of the sound speed, and there is no need for complex real-time correction of the sound speed.

[0050] The sonar host generates an acoustic emission signal; controls the phased array antenna to generate a specified beam; amplifies the acoustic echo signal received by the phased array antenna, processes the data and outputs the wind direction and wind speed of each altitude layer; records the ground wind direction and wind speed data of the ultrasonic wind measuring device and performs data fusion and outputs it to the host computer system. The ultrasonic wind measuring device completes the detection of ground wind and transmits the ground wind data to the sonar host. The sonar host is set in the form of a chassis and is set below the phased array acoustic antenna device.

[0051] refer to Fig. 9 , 16 The sonar host includes a power module, a signal processing module, a receiving module, a transmitting module and a beam control module. When the acoustic detection radar is working, the sonar host generates a short pulse signal, which is amplified by the transmitting module and sent to the antenna, and then the antenna transmits the acoustic pulse signal to the lower atmosphere. The pulse signal propagates directionally in the atmosphere.

[0052] The data processing module receives the instructions of the host computer system, pre-sets the working state according to the instructions, generates the acoustic wave signal required by the transmitting module, and sends it to the acoustic array antenna through the beam control module. The acoustic array antenna forms a specified beam according to the beam control module and transmits it, and receives the acoustic echo signal, and sends it to the receiving module through the beam control network. The receiving module amplifies the signal, processes it and sends it to the data processing module. The data processing module performs beam synthesis, signal extraction, accumulation and processing according to the received signal to obtain the echo power spectrum, and then calculates the wind direction and wind speed according to the Doppler frequency shift signal on each beam, and corrects the wind direction and wind speed according to the attitude information, and then performs data fusion with the ground wind measured by the ultrasonic wind measuring device, and sends it to the host computer system through the network in the specified format. The power supply module stabilizes and filters the 28V DC signal given by the host computer system and outputs the DC voltage required by each unit.

[0053] refer to Fig.10 The beam control module completes the switching among the five east, south, west, north and center beams of the phased array antenna, and forms five transmit beams and five receive beams through the transmit / receive switching; the beam switching is completed by the transmit / receive switching device through 16 solid-state electronic relays, and the transmit / receive switching device is the same as the transmit / receive switching device in Example 1.

[0054] When the acoustic detection radar is working, the sonar host generates a short pulse signal, which is amplified by the transmitting module and sent to the antenna, and then the acoustic pulse signal is emitted to the lower atmosphere through the antenna. The pulse signal propagates directionally in the atmosphere; when the transmitted signal encounters turbulence in the atmosphere, various scattering occurs. When the turbulence scale of various isotropic factors is equivalent to the wavelength of the sound wave, the scattering is strongest, and the echo in the opposite direction of the emission is called the backscattered echo. The acoustic detection radar antenna receives the backscattered echo and sends it to the receiving module through the beam control module. The receiving module amplifies and filters the signal and sends it to the data processing module. The data processing module collects and processes the echo signal in this direction, obtains the Doppler frequency shift in the radial direction, and then converts it into radial wind speed.

[0055] Acoustic radar measurement of three-dimensional wind speed requires synthesis of three radial wind speeds that are not in the same plane. This application uses a five-beam method, one vertical beam and four inclined beams, with an inclination angle between 15 and 30 degrees, and located in two mutually perpendicular planes, such as Fig.11 shown.

[0056] Based on the relationship between radial wind speed and Doppler frequency shift , get ,

[0057] Where C is the speed of sound in the air when there is no wind, λ is the wavelength of the sound wave, is the sound wave frequency, is the wind speed, The frequency shift of sound waves.

[0058] By calculating the radial Doppler frequency, the wind speed in each radial direction can be obtained. is the wind speed in the radial direction of the beam, U, V, and W represent the components of the wind speed vector in the east, north, and vertical directions, respectively. is the beam tilt angle, then

[0059]

[0060]

[0061]

[0062] Thus there is

[0063] U and V are two components of horizontal wind speed, and then they are combined into horizontal wind speed to get the horizontal wind speed. and offset angle They are

[0064] in It is a constant determined by the positive and negative values ​​of U and V.

[0065] In a specific scenario, the phased array antenna array is arranged from west to east, and the phase of each column is advanced by 90 degrees in sequence, so that the transmission beam can be controlled to tilt to the west. The three-dimensional simulation diagram of the "west beam" corresponding to the phased array antenna array is shown as follows: Fig.12 The normalized plane lobe diagram of the beam is shown as Figure 13-14 shown.

[0066] And so on: From west to east, the phase of each column lags by 90 degrees, which controls the transmit beam to tilt eastward; From north to south, the phase of each row is advanced by 90 degrees, which controls the transmit beam to tilt toward the north. From north to south, the phase of each row lags by 90 degrees, which controls the transmit beam to tilt toward the south. When all array elements are in phase, the transmit beam points vertically upward.

[0067] All array elements contain four phases: 0°, 90°, 180°, and 270°. Since the phases of 0° and 180°, and 90° and 270° differ by 180°, an inverter can be used to realize two inverted signals. Therefore, only two signals with a phase difference of 90° are needed to generate an oblique beam as shown in the figure. When the two signals have the same phase, a vertical beam is generated. This is the principle of the phased array during transmission.

[0068] The data processing module mainly completes the generation of transmission waveform, echo signal collection, transceiver signal array control, digital beamforming processing, signal-to-noise ratio optimization processing, layered power spectrum processing, wind parameter calculation, communication interface, etc. The functional block diagram of the data processing module is as follows Fig.17 As shown. The data processing module is implemented using ADI's low-power ADSP-SC589 as the core DSP circuit. The power consumption at high temperature is less than 2W, which can bring industry-leading digital signal processing performance. The ADSP-SC589 product complements the SHARC+ core and DSP accelerator series, and adds an ARM® Cortex-A5 processor. The FPU and Neon® DSP extended instruction set can handle additional real-time processing tasks and manage peripherals. These interfaces include Gigabit Ethernet interface, high-speed USB interface, serial port, mobile storage and a variety of other connection options to create a flexible and streamlined system design.

[0069] The data processing module is equipped with intelligent data processing software, see Fig.18 The data processing software includes signal self-check module, signal generation module, beam control module, signal acquisition and processing module, data fusion and processing module, and data communication module. Fig.19 , the software workflow is as follows: after the system is powered on, the system self-checks. If the system self-check is abnormal, an error message is prompted and the system stops working. If the system self-check is normal, the environmental noise is detected. Then wait for the command from the host computer and the start command to start the measurement. First, the waveform is transmitted, then the echo data is received and processed, and the intermediate results are saved. At the end of each sub-frame processing, the real-time clock is used to determine whether a frame time has arrived. If not, the work of a sub-frame is repeated; if it has arrived, a frame data processing function is called to sort out the data of each sub-frame in the frame, obtain the final result, and pass it out.

[0070] In a specific application scenario, the low-altitude wind detection radar is installed on a vehicle, a recess or a mounting frame is provided on the top of the vehicle for installing the low-altitude wind detection radar, and the ultrasonic wind measuring device is installed on the side of the vehicle.

[0071] The low-altitude wind phased array acoustic detection radar device in this embodiment is mainly used to detect the wind direction, wind speed and vertical airflow at a specified altitude layer from 0m to 200m in the air, and its effective detection height can even reach 500m. Compared with wind profile radar and sounding balloon, the low-altitude wind phased array acoustic detection radar device in this embodiment has higher detection accuracy for low-altitude wind and provides a vertical airflow detection function, which is a function that wind profile radar and sounding balloon do not have.

[0072] The low-altitude wind phased array acoustic detection radar device in this embodiment has a main detection range of: a) height: 0m~200m (55dBA humidity 70%RH); b) wind speed: 0m / s~30m / s; c) wind direction: 0~360º; the measurement accuracy is: a) wind speed: ≤1m / s (wind speed is less than 10m / s), ≤10% of wind speed (wind speed is greater than 10m / s); b) wind direction: ≤10° (wind speed is greater than 2m / s); c) vertical airflow: ≤0.5m / s.

[0073] The above is only a preferred implementation of the present application. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present application, and these all fall within the scope of protection of the present application.

Claims

1. A low-altitude wind phased array acoustic detection radar device, characterized in that: include: A phased array antenna array, wherein the phased array antenna array comprises a plurality of reversible transceiver transducers forming an equidistant square array, wherein transducers in the same row have the same operating frequency, and transducers in different rows have different operating frequencies; A transmitting unit, the transmitting unit is used to output a transmitting signal to the phased array antenna array; A receiving unit, the receiving unit is used to receive an echo signal of a phased array antenna array; A beam control unit, the beam control unit comprising a transceiver switching device, the transceiver switching device is used to control the transceiver switching of the phased array antenna array; and a data processing unit for receiving and intelligently processing echo signals.

2. The low-altitude wind phased array acoustic detection radar device according to claim 1 is characterized in that: In the phased array antenna array, the operating frequency of each row of transducers is equidistantly distributed. Specifically, the operating frequency of each row of transducers is: ； in, is the operating frequency of the i-th row transducer, To set the base frequency, is the operating frequency difference between adjacent rows of transducers.

3. The low-altitude wind phased array acoustic detection radar device according to claim 2 is characterized in that: The transmitting unit has several paths, each used to transmit signals to different rows of transducers, and the output signal frequency of each path is adapted to the working frequency of each row of transducers; The receiving unit has several paths, which are respectively used to receive echo signals of transducers in different rows. Each path includes a transceiver switch, a transformer, a low noise amplifier, a filter and a programmable gain amplifier.

4. The low-altitude wind phased array acoustic detection radar device according to claim 1, characterized in that: The data processing unit includes a noise processing unit, and the noise processing unit is used to intelligently suppress the noise in the echo signal, and the steps are: Perform fast Fourier transform on the obtained echo signals to obtain ,in, represents the fast Fourier transform result of the j-th echo signal; Compare the transformed echo signals of several paths, mark the frequency signals whose amplitude differences among the echo signals are within the preset value as noise signals and delete them to obtain , It represents the result after removing the noise from the j-th echo signal.

5. The low-altitude wind phased array acoustic detection radar device according to claim 4, characterized in that: Any n-way signal In the formula, n is a positive integer greater than or equal to 2 and less than the number of rows of the phased array antenna. For a signal of any frequency, if the amplitude ratio difference is less than τ, τ is a preset threshold, the frequency signal is judged to be a noise signal.

6. The low-altitude wind phased array acoustic detection radar device according to claim 1, characterized in that: The acoustic radar device also includes an antenna heating device, which includes an automatic temperature controller, a temperature sensor and a heating cable. The heating cable is coiled at the bottom of the transducer. The temperature sensor is arranged in the phased array antenna array or next to the phased array antenna array to detect the temperature of the phased array antenna array. The automatic temperature controller is used to control the heating cable to be energized when the temperature of the phased array antenna array is lower than a set value.

7. The low-altitude wind phased array acoustic detection radar device according to claim 1, characterized in that: The acoustic radar device also includes an radome, the opening of which gradually increases, the phased array antenna array is installed at the bottom of the radome, and a sound-absorbing sponge or a sound-absorbing plate is provided in the radome; a protective net is provided at the opening of the radome.

8. The low-altitude wind phased array acoustic detection radar device according to claim 1, characterized in that: The sonar device also includes an ultrasonic wind measuring device, an ultrasonic wind measuring instrument and a manual lifting rod. The ultrasonic wind measuring instrument includes a transmitting surface and a reflecting surface that are relatively arranged. The transmitting surface and the reflecting surface are both arc-shaped. Four ultrasonic probes are arranged on the transmitting surface, and the ultrasonic probes are ultrasonic probes that are integrated with transmitting and receiving.

9. The low-altitude wind phased array acoustic detection radar device according to claim 1, characterized in that: The manual lifting rod includes an external fixed rod, an internal telescopic rod, a fixed base, a clamp fixing seat, a locking sleeve, a live buckle, a limit pin, and an internal guide sleeve, wherein the fixed base and the clamp fixing seat are arranged on a fixed object, the external fixed rod is installed on the fixed base and the clamp fixing seat to achieve fixation, the internal telescopic rod is arranged in the external fixed rod and can be telescopically moved, the locking sleeve is arranged at the end of the external fixed rod, and has a live buckle on it for adjusting the locking degree of the locking sleeve, when locking, the internal telescopic rod is clamped and fixed by the external fixed rod, and when not locked, the internal telescopic rod can be manually extended and retracted to adjust the extension height of the internal telescopic rod.

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