Wind shear identification and warning method and device based on a wind measurement lidar

Abstract

The present invention discloses a low-altitude wind shear identification and warning system based on a wind measurement lidar. The present invention can utilize the measured radial velocity of the wind measurement lidar for the airport runway to perform real-time identification and warning of the low-altitude wind shear on the airport runway. First, a two-dimensional horizontal wind vector is obtained based on the measured radial velocity of the lidar. Then, the coordinates and wind vector of the measurement points are projected onto the runway coordinate system, and the measurement points falling within the monitoring areas of each runway are screened to give warnings for headwind and crosswind. The center of the shear section with a wind shear greater than the specified threshold is projected onto the central axis of the runway, the distribution of the centers of the wind shear sections greater than the wind shear threshold on the runway is statistically analyzed, the occurrence location of the wind shear is determined according to the number of shear sections, and a real-time warning message is given. The wind shear identification method of the present invention can quickly, accurately, and clearly identify and warn of wind shear, ensuring the flight safety of aircraft.

Description

Technical Field

[0001] The present invention relates to the fields of wind measurement lidar and airport meteorological support, and particularly to a method and device for wind shear identification and early warning based on wind measurement lidar. Background Art

[0002] With the continuous growth of the total volume of air transportation, the flight density of aircraft has also expanded rapidly, and airport wind shear accidents have been continuously reported. Encountering low-altitude wind shear will cause an instantaneous change in the aircraft speed, which will in turn cause a change in the aircraft lift, resulting in the flight track deviating from the airway and causing an accident. The international aviation community believes that the consequences caused by wind shear during the entire flight process mainly seriously affect the takeoff and landing processes of the aircraft. Therefore, people have given the low-altitude wind shear the titles of the "invisible killer" and "air trap" that affect aircraft flight safety. The low-altitude wind shear seriously threatens flight safety. In addition, too strong a tailwind will cause a sharp drop in lift, easily leading to an accident, and too strong a crosswind will easily cause the aircraft to deviate from the runway. These dangerous weather conditions have characteristics such as strong intensity, short duration, and intermittent occurrence, seriously endangering the safety of aircraft during the takeoff and landing phases and the cruise phase. Therefore, the accurate detection and timely early warning of dangerous weather are very important.

[0003] At present, there are many means for detecting the airport atmospheric wind field, but each has its own advantages, disadvantages, and different application scenarios. For example, an ultrasonic anemometer can only achieve single-point measurement, a wind profiler cannot monitor the full-field horizontal wind field, and a Doppler weather radar is not applicable under clear sky conditions. The Doppler lidar for wind measurement has high spatio-temporal resolution and a flexible scanning method, and has gradually been applied to the detection of the airport atmospheric wind field in recent years. At present, the accuracy and stability of the early warning algorithm for dangerous weather based on wind measurement lidar are poor. In actual operations, it mainly relies on forecasters and a variety of detection devices, and there is still room for improvement in accuracy and coverage. At present, when using lidar to detect wind shear, the radar needs to be close enough to the runway to ensure that the glide path direction is as parallel as possible to the scanning beam direction, and it is difficult to take into account multiple runways. And using a single profile to identify wind shear is prone to missing wind shear reports. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for low-altitude wind shear early warning based on lidar. Based on only using one wind measurement lidar, according to the data measured in real time by the wind measurement lidar, the wind speed changes of multiple airport runways are monitored to achieve wind shear early warning.

[0005] The present invention is implemented as follows: A method for wind shear identification and early warning based on wind measurement lidar includes:

[0006] Using a scanning wind measurement lidar to perform radar scanning on a target area within a preset elevation angle and azimuth angle range;

[0007] Obtain the echo signal corresponding to each radar scan, and based on each of the echo signals, obtain the measured radial wind speed:

[0008] Synthesize a two-dimensional horizontal wind field according to the measured radial wind speed;

[0009] Decompose the horizontal wind field into a component parallel to the target runway direction and a component perpendicular to the target runway direction;

[0010] According to a preset target monitoring area, screen out the measured point wind fields within the monitoring area;

[0011] Calculate the headwind component and the crosswind component according to the screened measured point wind fields and the preset flight direction; give a headwind warning and a crosswind warning according to the distribution of the calculated headwind component and crosswind component on the target runway;

[0012] Take the difference between the wind speeds of all measured points in the target monitoring area pairwise, and calculate a preset wind shear parameter; according to the calculation results, obtain the wind shear center and the shear section length corresponding to when both the wind shear magnitude and the wind shear intensity factor are greater than their respective preset thresholds;

[0013] Project the wind shear center obtained when it is greater than the preset wind shear threshold to a predetermined position on the target runway; give a wind shear warning according to the distribution of the wind shear center on the target runway.

[0014] Further, the synthesizing a two-dimensional horizontal wind field according to the measured radial wind speed includes:

[0015] Use the variational method to calculate the two-dimensional wind field components, and its objective function is as follows:

[0016] ;

[0017] where:

[0018] ;

[0019] ;

[0020] ;

[0021] ;

[0022] where is the background velocity term, is the radial velocity term, is the tangential velocity; is the smoothing term, which is determined by divergence, vorticity and the Laplacian operator; is the weight of the background velocity term, is the weight of the radial velocity term, is the weight of the tangential velocity; is the weight of the smoothing term. and are the velocity components in the north-south and east-west directions respectively; and are the initial values of the velocity components in the north-south and east-west directions respectively; is the measured radial velocity, is the estimated radial velocity; is the azimuth angle; i, j are the subscripts of the grid nodes, is the length of the grid node;

[0023] The estimated tangential velocity is expressed as:

[0024] ;

[0025] To ensure that the projection of the inverted horizontal wind field in the radar radial direction is as consistent as possible with the true wind field, the estimated radial velocity value and the measured radial velocity are used to recalculate the velocity components in the north-south and east-west directions, and the second horizontal velocity vector is:

[0026] ;

[0027] ;

[0028] wherein, is the second velocity component in the north-south direction; is the second velocity component in the east-west direction.

[0029] Furthermore, decomposing the horizontal wind field into a downwind component parallel to the target runway direction and a crosswind component perpendicular to the target runway direction includes:

[0030] Let the angle between the target runway and the due north direction be , the center coordinate of the radar coordinate system is , taking the runway center as the origin , setting the direction parallel to the runway center axis as axis, and the direction perpendicular to the runway center axis as axis, establishing a plane rectangular coordinate system , then the measuring point coordinates of the runway , ) are:

[0031] ;

[0032] ;

[0033] The corresponding downwind component and crosswind component are expressed as:

[0034] ;

[0035] .

[0036] Furthermore, according to the runway monitoring area, the measured point wind fields within the monitoring area are screened out, including:

[0037] First, the runway The monitoring area is divided into 7 regions, numbered 3MF, 2MF, 1MF, RWY, 1MD, 2MD, and 3MD respectively;

[0038] In the runway coordinate system below, the corresponding regions are respectively:

[0039] 3MF ;

[0040] 2MF ;

[0041] 1MF ;

[0042] RWY ;

[0043] 1MD ;

[0044] 2MD ;

[0045] 3MD ;

[0046] Among them is 1 unit length, is the length of runway k;

[0047] Extract the wind speeds falling within the target monitoring area according to the definition of the above monitoring area.

[0048] Furthermore, calculate the downwind component and crosswind component according to the screened measured point wind fields and the preset flight direction; give downwind warnings and crosswind warnings based on the distributions of the calculated downwind component and crosswind component on the runway; including:

[0049] Calculate the wind direction according to the screened measured point wind fields;

[0050] According to the preset determination conditions, when the wind direction is consistent with the preset flight direction, it is determined as the downwind component; when the wind direction is perpendicular to the preset flight direction, it is determined as the crosswind component;

[0051] When the proportion of the measuring points where the obtained downwind component is greater than the specified downwind threshold exceeds the preset first threshold, a downwind warning is given;

[0052] When the proportion of the measuring points where the obtained crosswind component is greater than the specified crosswind threshold exceeds the preset second threshold, a crosswind warning is given.

[0053] Furthermore, for the measuring points in the target runway monitoring area, calculate the preset wind shear parameter; according to the calculation result, obtain the wind shear center and the shear section length corresponding to the wind shear magnitude greater than the preset wind shear threshold; including:

[0054] For the measuring points in the target runway monitoring area, calculate the wind shear magnitude ; the wind shear magnitude includes downwind shear , crosswind shear and horizontal shear ;

[0055] Among them, the downwind shear );

[0056] The crosswind shear ;

[0057] The horizontal shear ;

[0058] , represent any two points in the monitoring area, with coordinates and ;

[0059] The length of the shear section is ;

[0060] The shear center is ;

[0061] The wind shear intensity factor ;

[0062] According to the wind shear intensity factor , filter out the wind shear sections with gentle changes; is the airspeed of the target aircraft;

[0063] When the wind shear magnitude and the wind shear intensity factor are both greater than their respective preset thresholds, record the shear section information .

[0064] Further, projecting the wind shear center obtained when it is greater than a preset wind shear threshold onto a predetermined position of the target runway includes:

[0065] Projecting the wind shear center obtained when it is greater than a preset wind shear threshold onto the central axis of the target runway.

[0066] Further, giving a wind shear warning according to the distribution of the wind shear center on the target runway, including

[0067] Counting the number of shear section centers in each monitoring area, and when the number of shear centers in the target monitoring area is greater than a specified threshold, giving a wind shear warning message.

[0068] Further, the present invention also provides a wind shear identification and warning device based on a wind measurement lidar, including:

[0069] A scanning module, configured to perform radar scanning on a target area by using a scanning wind measurement lidar within a preset elevation angle and azimuth angle range;

[0070] A wind field data acquisition module, configured to obtain an echo signal corresponding to each radar scan, and obtain an actually measured radial wind speed based on each of the echo signals:

[0071] A horizontal wind field acquisition module, configured to synthesize a two-dimensional horizontal wind field according to the actually measured radial wind speed;

[0072] A horizontal wind field decomposition module, configured to decompose the horizontal wind field into a component parallel to the direction of the target runway and a component perpendicular to the direction of the target runway;

[0073] A wind field screening module, configured to screen out the measured point wind fields within the monitoring area according to a preset target monitoring area;

[0074] A headwind and crosswind warning module, configured to calculate a headwind component and a crosswind component according to the screened measured point wind fields and a preset flight direction; giving a headwind warning and a crosswind warning according to the distribution of the calculated headwind component and crosswind component on the target runway;

[0075] A wind shear calculation module, configured to calculate a preset wind shear parameter by taking the difference between the wind speeds of all measured points within the target monitoring area pairwise; obtaining a wind shear center and a shear section length corresponding to when both the wind shear magnitude and the wind shear intensity factor are respectively greater than their respective preset thresholds according to the calculation result;

[0076] A wind shear warning module, configured to project the wind shear center obtained when it is greater than a preset wind shear threshold onto a predetermined position of the target runway; giving a wind shear warning according to the distribution of the wind shear center on the target runway.

[0077] Further, the headwind and crosswind warning module includes:

[0078] A wind direction calculation unit for calculating the wind direction according to the selected measured point wind field;

[0079] A headwind component and crosswind component acquisition unit for determining the headwind component according to a preset determination condition when the wind direction is consistent with the preset flight direction; and determining the crosswind component when the wind direction is perpendicular to the preset flight direction;

[0080] A headwind warning unit for giving a headwind warning when the proportion of the number of measured points with the acquired headwind component greater than the specified headwind threshold exceeds a preset first threshold;

[0081] A crosswind warning unit for giving a crosswind warning when the proportion of the number of measured points with the acquired crosswind component greater than the specified crosswind threshold exceeds a preset second threshold.

[0082] In summary, the present invention provides a method for wind shear identification and warning based on a wind measurement lidar. The method uses a scanning wind measurement lidar to obtain echo signals corresponding to each radar scan, and based on each of the echo signals, obtains the measured radial wind speed: synthesizes a two-dimensional horizontal wind field according to the measured radial wind speed; decomposes the horizontal wind field into a component parallel to the target runway direction and a component perpendicular to the target runway direction; screens out the measured point wind fields in the monitoring area; calculates the headwind component and crosswind component according to the selected measured point wind field and the preset flight direction; gives a headwind warning and a crosswind warning according to the distribution of the calculated headwind component and crosswind component on the target runway; calculates the preset wind shear parameter by taking the difference between the wind speeds of all measured points in the target monitoring area in pairs; projects the wind shear center when the acquired value is greater than the preset wind shear threshold to a predetermined position on the target runway; and gives a wind shear warning according to the distribution of the wind shear center on the target runway. The wind shear identification method of the present invention can quickly, accurately and clearly identify and warn the wind shear of multiple runways in the target area, ensure the flight safety of the aircraft, and has the advantages of no missed reports, strong flexibility, high spatio-temporal resolution and high accuracy. Description of the Drawings

[0083] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0084] Figure 1 It is a flowchart of the method for wind shear identification and warning based on a wind measurement lidar provided by the embodiment of the present invention;

[0085] Figure 2 Flow chart of the headwind and crosswind warning method provided by the embodiment of the present invention;

[0086] Figure 3 Schematic diagram of the headwind recognition case provided by the embodiment of the present invention;

[0087] Figure 4 Schematic diagram of the wind shear case provided by the embodiment of the present invention;

[0088] Figure 5 Structural block diagram of the wind shear recognition and warning device based on the wind measurement lidar provided by the embodiment of the present invention;

[0089] Figure 6 Structural block diagram of the headwind and crosswind warning module provided by the embodiment of the present invention. Detailed implementation manners

[0090] The following combines the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0091] Embodiment:

[0092] The present invention discloses a wind shear recognition and warning method based on a wind measurement lidar, Figure 1 which is the flow chart of the method provided by the embodiment of the present invention, and its specific implementation is as follows:

[0093] Step S1: Use a scanning wind measurement lidar to perform radar scanning on the target area within a preset elevation angle and azimuth angle range.

[0094] Specifically, the lidar performs a low-elevation PPI scan to collect the horizontal radial wind field in real time. Among them, PPI is the abbreviation of Plan Position Indicator, a planar position indicator.

[0095] The elevation angle is preferably set to 0°-7°, so that the aircraft glide path area on the ground runway can be monitored simultaneously.

[0096] The azimuth angle corresponds to the area of the target area.

[0097] Step S2: Obtain the echo signal corresponding to each radar scan, and obtain the measured radial wind speed based on each of the echo signals.

[0098] Specifically, after obtaining the echo signal corresponding to each radar scan, the measured radial wind speed can be calculated according to a preset algorithm.

[0099] The wind measurement lidar obtains the frequency information of the echo signal according to a preset algorithm. The corresponding relationship between the frequency information, the seed light frequency, and the wind speed is:

[0100] v - v0 = V * 2 / λ;

[0101] where v is the signal frequency returned by the target, v0 is the seed light frequency, V is the wind speed, and λ is the seed light wavelength. The measured radial wind speed can be obtained according to the above formula.

[0102] Step S3: Synthesize a two-dimensional horizontal wind field based on the measured radial wind speed.

[0103] Specifically, the method for inverting the horizontal wind vector according to the present invention is as follows:

[0104] Taking the lidar as the origin, the due north direction as the axis, and the due west direction the axis, a plane radar coordinate system is established. The radar azimuth angle is , with the azimuth angle of 0 degrees pointing due north and 90 degrees pointing due east. Then the coordinates of each range gate of the radar can be expressed as:

[0105] ,

[0106] where is the radar elevation angle, is the radar detection radius.

[0107] The variational method is used to calculate the two-dimensional wind field components, and its objective function is as follows:

[0108]

[0109] where:

[0110]

[0111]

[0112]

[0113]

[0114] where is the background velocity term, is the radial velocity term, is the tangential velocity; is the smoothing term, which is determined by the divergence, vorticity, and Laplacian operator; is the weight of the background velocity term, is the weight of the radial velocity term, is the weight of the tangential velocity; is the weight of the smoothing term. and are the component velocities in the north-south and east-west directions respectively, and are expressed by polynomial expansion, such as the second-order Legendre polynomial, etc. Let we can obtain and ; and are the initial values of the component velocities in the north-south and east-west directions respectively; is the measured radial wind velocity, is the estimated radial velocity; is the azimuth angle; i, j are the subscripts of the grid nodes, is the length of the grid node;

[0115] The further tangential velocity can be expressed as

[0116] ;

[0117] To ensure that the projection of the inverted horizontal wind field in the radar radial direction is as consistent as possible with the true wind field, the second horizontal velocity vector is recalculated as:

[0118] ;

[0119] ;

[0120] wherein, is the component velocity in the second north-south direction; is the component velocity in the second east-west direction.

[0121] Step S4: Decompose the horizontal wind field into components parallel to the target runway direction and perpendicular to the target runway direction.

[0122] Let the target runway make an angle of with the due north direction, and the center coordinate of the radar coordinate system is . Taking the runway center as the origin , the direction parallel to the runway central axis is set as axis, and the direction perpendicular to the runway central axis is set as axis, and a plane rectangular coordinate system is established. Then the measurement point coordinates of the runway , ) are:

[0123] ;

[0124] ;

[0125] The corresponding downwind component and the crosswind component are expressed as:

[0126] ;

[0127] .

[0128] Step S5: According to the runway monitoring area, filter out the measured point wind fields within the monitoring area.

[0129] In a preferred embodiment, first, the runway monitoring area is divided into 7 areas, numbered 3MF, 2MF, 1MF, RWY, 1MD, 2MD, 3MD respectively;

[0130] In the runway coordinate system the corresponding areas are:

[0131] 3MF ;

[0132] 2MF ;

[0133] 1MF ;

[0134] RWY ;

[0135] 1MD ;

[0136] 2MD ;

[0137] 3MD ;

[0138] wherein is 1 unit length, is the length of runway k;

[0139] Extract the wind speeds falling within the target monitoring area according to the definition of the above monitoring area.

[0140] Step S6: Calculate the downwind component and the crosswind component according to the filtered measured point wind fields and the preset flight direction; Give downwind warnings and crosswind warnings based on the distributions of the calculated downwind component and crosswind component on the target runway.

[0141] As Figure 2 shown, step S6 includes:

[0142] S601. Calculate the wind direction according to the filtered measured point wind fields;

[0143] S602. According to the preset determination conditions, when the wind direction is consistent with the preset flight direction, it is determined as the downwind component; when the wind direction is perpendicular to the preset flight direction, it is determined as the crosswind component.

[0144] S603. When the proportion of the measurement points where the obtained downwind component is greater than the specified downwind threshold exceeds the preset first threshold, a downwind warning is given.

[0145] S604. When the proportion of the measurement points where the obtained crosswind component is greater than the specified crosswind threshold exceeds the preset second threshold, a crosswind warning is given.

[0146] Specifically, in one embodiment, the first threshold can be 80%; the specified downwind threshold can be 10 kt (5.1 m / s); when the proportion of the number of measurement points where the downwind component (wind direction is consistent with the flight direction) in the monitoring area > 10 kt (5.1 m / s) exceeds 80%, a downwind warning (HWA) is issued for this area.

[0147] The first threshold can be 80%; the specified downwind threshold can be 15 kt (7.7 m / s); when the proportion of the number of measurement points where the crosswind component (wind direction is perpendicular to the flight direction) in the monitoring area > 15 kt (7.7 m / s) exceeds 80%, a crosswind warning (CWA) is issued for this area.

[0148] The following uses a specific measurement data to explain the downwind identification and warning method.

[0149] As Figure 3 shown, (a)-(d) are the distributions of the downwind components of the 4 runways (35L / 17R, 35R / 17L, 01L / 19R, 29R / 11L) of Beijing Daxing Airport respectively, and the warning messages given according to the method of the present invention are

[0150] 'UTC 2021-06-20 09:53:17 17R HWA +5.0 2MD '

[0151] 'UTC 2021-06-20 09:53:17 17R HWA +5.5 1MD '

[0152] 'UTC 2021-06-20 09:53:17 35L HWA +6.7 RWY'

[0153] 'UTC 2021-06-20 09:53:17 35L HWA +7.0 1MF '

[0154] 'UTC 2021-06-20 09:53:17 35L HWA +6.6 2MF '

[0155] 'UTC 2021-06-20 09:53:17 35L HWA +6.3 3MF '

[0156] Among them, the warning message 'UTC 2021-06-20 09:53:17 35L HWA +6.6 2MF 'is consistent with the position reported by the crew ( Figure 3 (a) shaded position).

[0157] Step S7: Calculate the preset wind shear parameters for the measuring points in the monitoring area of the target runway; obtain the wind shear center and the shear section length corresponding to the wind shear magnitude greater than the preset wind shear threshold according to the calculation results.

[0158] Calculate the wind shear magnitude for the measuring points in the monitoring area of the target runway ; The wind shear magnitude includes headwind shear , crosswind shear and horizontal shear ;

[0159] Among them, headwind shear );

[0160] Crosswind shear ;

[0161] Horizontal shear ;

[0162] , represent any two points in the monitoring area, with coordinates and ;

[0163] The length of the shear section is ;

[0164] The shear center is ;

[0165] Wind shear intensity factor ;

[0166] Filter out the wind shear sections with gentle changes according to the wind shear intensity factor ; is the airspeed of the target aircraft;

[0167] When both the wind shear magnitude and the wind shear intensity factor are respectively greater than their preset thresholds, record the shear section information .

[0168] Step S8: Project the wind shear center obtained when it is greater than the preset wind shear threshold onto a predetermined position of the target runway; give a wind shear warning according to the distribution of the wind shear center on the target runway.

[0169] Specifically, projecting the wind shear center obtained when it is greater than the preset wind shear threshold onto a predetermined position of the target runway includes: projecting the wind shear center obtained when it is greater than the preset wind shear threshold onto the central axis of the target runway. In this way, the central position around the target runway can be obtained.

[0170] Giving a wind shear warning according to the distribution of the wind shear center on the target runway includes:

[0171] Count the number of shear segment centers in each monitoring area. When the number of shear centers in the target monitoring area is greater than the specified threshold, give a wind shear warning message.

[0172] It should be noted that the target runway of the present invention can be one or more. By using the method of the present invention to calculate each target runway separately, the wind speed information and wind shear information near multiple runways can be obtained, and the headwind warning, crosswind warning and wind shear warning in each area can be given respectively.

[0173] The following uses a specific measurement data to explain the headwind recognition and warning method:

[0174] As Figure 4 shown, (a)-(d) respectively show the distribution of the wind shear centers of the 4 runways (35L / 17R, 35R / 17L, 01L / 19R, 29R / 11L) of Beijing Daxing Airport. The warning messages given according to the method of the present invention are:

[0175] 'UTC 2021-05-26 10:36:50 19R WSA -7.9 1M '

[0176] 'UTC 2021-05-26 10:36:50 01L WSA -7.7 RWY'

[0177] 'UTC 2021-05-26 10:36:50 01L WSA +8.5 1M '

[0178] Among them, 'UTC 2021-05-26 10:36:50 01L WSA -7.7 RWY' is consistent with the position reported by the crew ( Figure 4 (a) shaded position).

[0179] As Figure 5 shown, the present invention also provides a wind shear recognition and warning device based on a wind measurement lidar, including:

[0180] A scanning module, configured to use a scanning wind lidar to perform radar scanning on a target area within a preset elevation angle and azimuth angle range;

[0181] A wind field data acquisition module, configured to obtain an echo signal corresponding to each radar scan, and based on each of the echo signals, obtain an actual measured radial wind speed:

[0182] A horizontal wind field acquisition module, configured to synthesize a two-dimensional horizontal wind field based on the actual measured radial wind speed;

[0183] A horizontal wind field decomposition module, configured to decompose the horizontal wind field into a component parallel to the target runway direction and a component perpendicular to the target runway direction;

[0184] A wind field screening module, configured to screen out the measured point wind fields within the monitoring area according to a preset target monitoring area;

[0185] A headwind and crosswind warning module, configured to calculate a headwind component and a crosswind component according to the screened measured point wind fields and a preset flight direction; give a headwind warning and a crosswind warning according to the distribution of the calculated headwind component and crosswind component on the target runway;

[0186] A wind shear calculation module, configured to calculate a preset wind shear parameter by taking the difference between the wind speeds of all measured points within the target monitoring area in pairs; according to the calculation result, obtain the wind shear center and the shear section length corresponding to when both the wind shear magnitude and the wind shear intensity factor are greater than their respective preset thresholds;

[0187] A wind shear warning module, configured to project the wind shear center obtained when it is greater than a preset wind shear threshold onto a predetermined position of the target runway; give a wind shear warning according to the distribution of the wind shear center on the target runway.

[0188] As Figure 6 shown, the headwind and crosswind warning module includes:

[0189] A wind direction calculation unit, configured to calculate the wind direction according to the screened measured point wind fields;

[0190] A headwind component and crosswind component acquisition unit, configured to, according to a preset determination condition, when the wind direction is consistent with the preset flight direction, determine it as the headwind component; when the wind direction is perpendicular to the preset flight direction, determine it as the crosswind component;

[0191] A headwind warning unit, configured to give a headwind warning when the proportion of the number of measured points where the obtained headwind component is greater than a specified headwind threshold exceeds a preset first threshold;

[0192] A crosswind warning unit, configured to give a crosswind warning when the proportion of the measurement points where the acquired crosswind component is greater than a specified crosswind threshold exceeds a preset second threshold.

[0193] In summary, the present invention provides a method for identifying and warning wind shear based on a wind measurement lidar. The method includes: using a scanning wind measurement lidar to acquire echo signals corresponding to each radar scan, and obtaining the measured radial wind speed based on each of the echo signals; synthesizing a two-dimensional horizontal wind field according to the measured radial wind speed; decomposing the horizontal wind field into a component parallel to the target runway direction and a component perpendicular to the target runway direction; screening out the measured point wind fields within the monitoring area; calculating the headwind component and the crosswind component according to the screened measured point wind fields and a preset flight direction; giving a headwind warning and a crosswind warning according to the distributions of the calculated headwind component and crosswind component on the target runway; calculating a preset wind shear parameter by taking the difference between the wind speeds of all the measurement points in the target monitoring area pairwise; projecting the wind shear center when the acquired value is greater than a preset wind shear threshold to a predetermined position on the target runway; and giving a wind shear warning according to the distribution of the wind shear center on the target runway. The wind shear identification method of the present invention can quickly, accurately and clearly identify and warn the wind shear of multiple runways in the target area, ensure the flight safety of the aircraft, and has the advantages of no missed alarms, strong flexibility, high spatio-temporal resolution and high accuracy.

[0194] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A wind shear identification and warning method based on a wind measurement lidar, characterized in that, Including: Using a scanning anemometric lidar to perform radar scanning on a target area within a preset elevation angle and azimuth range; Obtaining echo signals corresponding to each radar scan, and obtaining measured radial wind speeds based on each of the echo signals; Synthesizing a two-dimensional horizontal wind field according to the measured radial wind speeds; Decomposing the horizontal wind field into a component parallel to the direction of the target runway and a component perpendicular to the direction of the target runway; According to a preset target monitoring area, screening out the measured point wind fields within the monitoring area; Calculating a headwind component and a crosswind component according to the screened measured point wind fields and a preset flight direction; giving a headwind warning and a crosswind warning according to the distributions of the calculated headwind component and crosswind component on the target runway; Taking the differences between the wind speeds of all measured points within the target monitoring area pairwise, and calculating a preset wind shear parameter; according to the calculation results, obtaining the wind shear center and the shear section length corresponding to when both the wind shear magnitude and the wind shear intensity factor are greater than their respective preset thresholds; Projecting the wind shear center obtained when it is greater than the preset wind shear threshold onto a predetermined position on the target runway; giving a wind shear warning according to the distribution of the wind shear center on the target runway.

2. The method according to claim 1, characterized in that, The synthesizing a two-dimensional horizontal wind field according to the measured radial wind speeds includes: Calculate the two-dimensional wind field components using the variational method, and its objective function is as follows: ； Wherein: ； ； ； ； Among them is the background velocity term, is the radial velocity term, is the tangential velocity; is the smoothing term, determined by divergence, vorticity and Laplacian operator; is the weight of the background velocity term, is the weight of the radial velocity term, is the weight of the tangential velocity; is the weight of the smoothing term, and are the velocity components in the north-south and east-west directions respectively; and are the initial values of the velocity components in the north-south and east-west directions respectively; is the measured radial wind velocity, is the estimated radial velocity; is the azimuth angle; i, j are the subscripts of grid nodes, is the length of the grid node; Estimated tangential velocity Expressed as: ； The second horizontal velocity vector is: ； ； Among them, is the second north-south component velocity; is the second east-west component velocity.

3. The method according to claim 1 or 2, characterized in that, Decomposing the horizontal wind field into a headwind component parallel to the direction of the target runway and a crosswind component perpendicular to the direction of the target runway includes: Set the target runway The included angle with the due north direction is , and the central coordinate of the radar coordinate system is . Taking the runway center as the origin , set the direction parallel to the runway central axis as axis, and the direction perpendicular to the runway central axis as axis, and establish a plane rectangular coordinate system . Then the measurement point coordinates of the runway , ) are as follows: ； ； Corresponding downwind component and crosswind component are expressed as: ； 。 4. The method according to claim 3, wherein According to a runway monitoring area, screening out the measured point wind fields within the monitoring area includes: First, the target runway The monitoring area is divided into 7 areas, numbered 3MF, 2MF, 1MF, RWY, 1MD, 2MD, and 3MD respectively; In the runway coordinate system the corresponding areas are respectively: 3MF ; 2MF ; 1MF ; RWY ; 1MD ; 2MD ; 3MD ; wherein is one unit length, is the length of runway k; Extracting the wind speeds falling within the target monitoring area according to the definition of the above-mentioned monitoring area.

5. The method according to claim 4, wherein Calculating a headwind component and a crosswind component according to the screened measured point wind fields and a preset flight direction; giving a headwind warning and a crosswind warning according to the distributions of the calculated headwind component and crosswind component on the runway includes: Calculating the wind direction according to the screened measured point wind fields; According to a preset determination condition, when the wind direction is consistent with the preset flight direction, it is determined as the headwind component; when the wind direction is perpendicular to the preset flight direction, it is determined as the crosswind component; When the proportion of the number of measured points where the obtained headwind component is greater than a specified headwind threshold exceeds a preset first threshold, giving a headwind warning; When the proportion of the number of measured points where the obtained crosswind component is greater than a specified crosswind threshold exceeds a preset second threshold, giving a crosswind warning.

6. The method according to claim 1, characterized in that Taking the differences between the wind speeds of all measured points within the target monitoring area pairwise, and calculating a preset wind shear parameter; according to the calculation results, obtaining the wind shear center and the shear section length corresponding to when the wind shear magnitude is greater than a preset wind shear threshold includes: Calculate the magnitude of wind shear for the measurement points within the target runway monitoring area ; The magnitude of the wind shear includes headwind shear , crosswind shear and horizontal shear ; Among them, the headwind shear ; Crosswind Shear ; Horizontal shear ; , represent any two points within the monitoring area, with coordinates and ; The length of the shear section is ; The shear center is ; Wind shear intensity factor ; According to the wind shear intensity factor , filter out the wind shear segments with gentle changes; is the airspeed of the target aircraft; When the magnitude of wind shear and the wind shear intensity factor are both greater than their respective preset thresholds, record the shear section information .

7. The method according to claim 1, characterized in that, Projecting the wind shear center obtained when it is greater than the preset wind shear threshold onto a predetermined position on the target runway includes: Projecting the wind shear center obtained when it is greater than the preset wind shear threshold onto the central axis of the target runway.

8. The method according to claim 1, wherein Giving a wind shear warning according to the distribution of the wind shear center on the target runway includes: Counting the number of shear section centers in each monitoring area, and when the number of shear centers within the target monitoring area is greater than a specified threshold, giving a wind shear warning message.

9. A wind shear identification and warning device based on a wind measurement lidar, characterized in that, Including: A scanning module, configured to use a scanning wind lidar to perform radar scanning on a target area within a preset elevation angle and azimuth angle range; A wind field data acquisition module, configured to obtain echo signals corresponding to each radar scan, and obtain measured radial wind speeds based on each of the echo signals; A horizontal wind field acquisition module, configured to synthesize a two-dimensional horizontal wind field based on the measured radial wind speeds; A horizontal wind field decomposition module, configured to decompose the horizontal wind field into a component parallel to the target runway direction and a component perpendicular to the target runway direction; A wind field screening module, configured to screen out the measured point wind fields within the preset target monitoring area according to the preset target monitoring area; A headwind and crosswind warning module, configured to calculate a headwind component and a crosswind component based on the screened measured point wind fields and a preset flight direction; give a headwind warning and a crosswind warning according to the distribution of the calculated headwind component and crosswind component on the target runway; A wind shear calculation module, configured to calculate a preset wind shear parameter by taking the difference between the wind speeds of all measured points in the target monitoring area pairwise; according to the calculation result, obtain the wind shear center and the shear section length corresponding to when both the wind shear magnitude and the wind shear intensity factor are greater than their respective preset thresholds; A wind shear warning module, configured to project the wind shear center obtained when it is greater than the preset wind shear threshold to a predetermined position on the target runway; give a wind shear warning according to the distribution of the wind shear center on the target runway.

10. The device according to claim 9, characterized in that, The headwind and crosswind warning module includes: A wind direction calculation unit, configured to calculate the wind direction based on the screened measured point wind fields; A headwind component and crosswind component acquisition unit, configured to determine a headwind component when the wind direction is consistent with the preset flight direction according to a preset determination condition; determine a crosswind component when the wind direction is perpendicular to the preset flight direction; A headwind warning unit, configured to give a headwind warning when the proportion of the number of measured points with the obtained headwind component greater than a specified headwind threshold exceeds a preset first threshold; A crosswind warning unit, configured to give a crosswind warning when the proportion of the number of measured points with the obtained crosswind component greater than a specified crosswind threshold exceeds a preset second threshold.

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