Airspace expansion detection and display method for airborne active phased array weather radar

Abstract

The present invention provides a method for airborne active phased array weather radar airspace expansion detection and display, comprising the following steps: Step 1: Acquire 3D multi-layer scan reflectivity data of the space in front of the carrier aircraft at time T0; Step 2: Calculate reflectivity data of the spatial weather model at time T0; Step 3: Calculate the position change information of the carrier aircraft relative to T0 at time T1; Step 4: Calculate the weather echo data of the expanded airspace portion of the carrier radar at time T1; Step 5: Based on the result of Step 4, obtain the expanded airspace detection data at time T1 and display it on the radar screen. By interpolating and storing the airborne 3D scan data as 3D grid data, an airspace weather model is generated. When the carrier aircraft scans within the airspace weather model, the relative position relationship between the carrier radar and the weather model can be used to calculate weather echo data for a larger scanning range. At the same time, the 3D grid data in a specific radar azimuth can be extracted to obtain altitude and distance information of weather targets.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to an airspace expansion detection and display method for an airborne active phased array weather radar. Background Art

[0002] Airborne weather radars detect weather information ahead of aircraft, guiding pilots in route planning and proactively avoiding potential hazards. With the development of aviation, weather radars must possess more robust detection capabilities, enabling more accurate, comprehensive, and real-time detection and display of weather threats to flight safety. Conventional airborne weather radars, due to their mechanically scanned antennas, typically take 3-6 minutes to complete an airspace survey. Their small size and rapid changes prevent them from obtaining a detailed, three-dimensional representation of hazardous weather conditions, such as thunderstorms, downbursts, and wind shear. Airborne active phased array (AESA) weather radars use electronically controlled radar beams to scan, offering advantages over mechanical scanning. Furthermore, phased array weather radars easily implement digital beamforming, enabling simultaneous multi-beam scanning of spatial targets at different altitudes and directions. Airborne AESA weather radars, with their diverse functionality, high maneuverability, short response time, high data rate, robust anti-interference capabilities, and high reliability, are currently a key development direction for airborne weather radars.

[0003] Airborne active phased array weather radars rely on electronic scanning to synthesize antenna pattern variations. Generally, at normal antenna gain, azimuth electronic scanning cannot achieve a full 180-degree forward range of airspace detection. Consequently, the airborne weather radar display also fails to fully display weather information in the airspace ahead, significantly underperforming traditional mechanical scanning weather radar displays. Therefore, methods are urgently needed to increase airspace detection range and expand radar display capabilities within airborne active phased array weather radar systems. Summary of the Invention

[0004] In view of this, an embodiment of the present specification provides an airspace expansion detection and display method for an airborne active phased array weather radar, so as to achieve the purpose of improving the airspace detection range of the airborne active phased array weather radar.

[0005] The embodiments of this specification provide the following technical solutions: a method for airborne active phased array weather radar airspace expansion detection and display, comprising the following steps: step 1, obtaining three-dimensional multi-layer scanning reflectivity data of the space in front of the carrier aircraft at time T0; step 2, calculating the reflectivity data of the spatial weather model at time T0; step 3, calculating the position change information of the carrier aircraft relative to T0 at time T1; step 4, calculating the weather echo data of the expanded airspace portion of the carrier radar at time T1; step 5, obtaining the airspace detection data after expansion at time T1 based on the result of step 4 and displaying it on the radar screen.

[0006] Furthermore, step 1 is specifically as follows: Step 1.1, obtaining the signal data modulus F received by the active phased array weather radar after completing a line scanning cycle at time T0 i (Nx, Ny), where Nx and Ny represent the azimuth and range sampling points respectively, i represents the pitch layer number of the stereo scan, and the value range of i is 1, 2...M, where M is the total pitch layer number; Step 1.2, the signal data modulus F i (Nx, Ny) is filtered, smoothed, and subjected to system noise elimination to obtain the modulus F i '(Nx,Ny), the modulus value F i Substitute (Nx, Ny) into the weather radar equation to calculate the reflectivity factor Z i (Nx, Ny), and put all pitch layer reflectivity factor data in the same structure data Z01.

[0007] Furthermore, step 2 is specifically as follows: the structure data Z01 is converted into and formula The reflectivity data Z02 of the space weather model is calculated, where w represents the weight of the radar volume scan data sampling point; r0, a0, e0 represent the mid-range, azimuth and elevation of the radar volume scan data spherical coordinates respectively; r, a, e represent the grid point spherical coordinates; k r ,k a ,k e The smoothing parameters of the interpolation method in radial, azimuth and elevation respectively; f a Represents the interpolated grid point data value; f0(i) represents the reflectance value of the i-th sampling point in the relevant influence area of the reflectance value of the grid point (r, a, e); N represents the number of sampling points in the influence area of the reflectance value of the grid point (r, a, e).

[0008] Furthermore, step three is specifically as follows: the latitude, longitude and altitude of the carrier position information is (X0, Y0, H0), and the latitude, longitude and altitude position information of the carrier at time T1 is (X1, Y1, H1). The position change information P (px, py, ph) at time T1 relative to time T0 can be calculated through the standard earth WGS84 coordinate system.

[0009] Furthermore, step four is: using the position change information at time T1 relative to time T0 obtained in step three, combined with the space weather model reflectivity data Z02 obtained in step two, and the aircraft radar system parameter heading angle, beam width and pulse width data, calculate the extended airspace weather radar echo reflectivity data Z12 corresponding to time T1 by simulating radar scanning.

[0010] Step 4 is as follows: Step 4.1, the polar coordinates corresponding to the position change information P(px,py,ph) at time T1 relative to time T0 are expressed as P'(R,α,β), where R is the radial distance; α is the azimuth angle, and β is the pitch angle; Step 4.2, calculate a sampling volume of particle scattering echoes within the range of beam distance R to R+h / 2 Wherein, the radar transmission pulse width is τ, and the pulse transmission propagation distance is h; the Cartesian coordinates corresponding to the center of the starting point section and the end point section of the sampling volume in steps 4.3 and 4.2 are Step 4.4, according to the formula Calculate the Cartesian coordinate increment of the beam width cross-section when setting the pitch angle and azimuth angle. Step 4.5, the sampling volume corresponding to the set point in space is approximately within the Cartesian coordinate system. Step 4.6: Use the results of steps 4.1 to 4.5 to simulate scanning the space weather model reflectivity data Z02 to obtain the airborne phased array weather radar extended space reflectivity factor data information Z12.

[0011] Furthermore, the airborne phased array meteorological radar expanded airspace reflectivity factor data information Z12 obtained in step 4.6 is combined with the phased array radar actual detection airspace reflectivity echo data Z11 at time T1 to obtain the expanded airspace detection data Z13 at time T1. At the same time, the expanded airspace detection data Z13 at time T1 is transmitted to the radar screen for display.

[0012] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least the following: by interpolating and storing the airborne stereoscopic scanning data as three-dimensional grid data, an airspace meteorological model is obtained. When the carrier aircraft scans in the airspace meteorological model, the relative position relationship between the carrier aircraft radar and the meteorological model can be used to calculate the meteorological echo data of a larger scanning range. At the same time, the three-dimensional grid data in a certain azimuth direction of the radar can also be extracted to obtain the height-distance information of the meteorological target. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 It is a flowchart of an embodiment of the present invention. DETAILED DESCRIPTION

[0015] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0016] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0017] A method for airspace expansion detection and display of an airborne active phased array weather radar comprises the following steps:

[0018] Step 1: Obtain the three-dimensional multi-layer scanning reflectivity data of the space in front of the carrier aircraft at time T0;

[0019] Step 2: Calculate the reflectivity data of the space weather model at time T0;

[0020] Step 3: Calculate the position change information of the carrier aircraft at time T1 relative to T0;

[0021] Step 4: Calculate the weather echo data of the extended airspace of the carrier aircraft radar at time T1;

[0022] Step 5: Based on the result of step 4, obtain the airspace detection data after the expansion at time T1 and display it on the radar screen.

[0023] The present invention obtains an airspace meteorological model by interpolating and storing airborne stereoscopic scanning data as three-dimensional grid data. When the carrier aircraft scans in the airspace meteorological model, the relative position relationship between the carrier aircraft radar and the meteorological model can be used to calculate meteorological echo data of a larger scanning range. At the same time, the three-dimensional grid data in a certain direction of the radar can also be extracted to obtain the altitude-distance information of the meteorological target.

[0024] Step 1 is as follows:

[0025] Step 1.1: Obtain the signal data modulus F received by the active phased array weather radar after completing a line scan cycle at time T0. i (Nx, Ny), where Nx and Ny represent the sampling points in the azimuth and range directions, respectively; i represents the elevation layer number of the stereo scan; the value range of i is 1, 2…M, and M is the total elevation layer number;

[0026] Step 1.2: Modulus F of signal data i (Nx, Ny) is filtered, smoothed, and subjected to system noise elimination to obtain the modulus F i '(Nx,Ny), the modulus value F i Substitute (Nx, Ny) into the weather radar equation to calculate the reflectivity factor Z i (Nx, Ny), and put all pitch layer reflectivity factor data in the same structure data Z01.

[0027] At time T0, the electronic scanning advantage of the active phased array weather radar is utilized to obtain the forward spatial stereoscopic multi-scan weather echo data. After filtering, smoothing, and system noise elimination, the reflectivity factor is substituted into the weather radar equation to obtain the spatial stereoscopic multi-scan reflectivity data Z01 in polar coordinates.

[0028] Step 2 is as follows: transform the structure data Z01 into and formula The reflectivity data Z02 of the space weather model is calculated, where w represents the weight of the radar volume scan data sampling point; r0, a0, e0 represent the mid-range, azimuth and elevation of the radar volume scan data spherical coordinates respectively; r, a, e represent the grid point spherical coordinates; k r ,k a ,k e The smoothing parameters of the interpolation method in radial, azimuth and elevation respectively; f a Represents the interpolated grid point data value; f0(i) represents the reflectance value of the i-th sampling point in the relevant influence area of the reflectance value of the grid point (r, a, e); N represents the number of sampling points in the influence area of the reflectance value of the grid point (r, a, e).

[0029] Using spatial stereo multi-scan reflectivity data in polar coordinates, the three-dimensional grid is interpolated into grid point data in Cartesian coordinates, and the influence of the earth's curvature is added in the interpolation process so that the finally calculated three-dimensional grid contour surface data is equivalent to the same horizontal plane at the full range of the radar. The three-dimensional grid data is the reflectivity Z02 of the space weather model data at time T0.

[0030] Step three is as follows: the latitude, longitude and altitude of the carrier position information are (X0, Y0, H0), and the latitude, longitude and altitude of the carrier position information at time T1 is (X1, Y1, H1). The position change information P (px, py, ph) at time T1 relative to time T0 can be calculated using the standard earth WGS84 coordinate system.

[0031] By using the changes in the inertial navigation position information such as the geographical location information, longitude, latitude and altitude at time T1 relative to time T0 during the flight of the carrier aircraft, the position change information P at time T1 in the coordinates of time T0 is calculated.

[0032] Step 4 is: using the position change information at time T1 relative to time T0 obtained in step 3, combined with the space weather model reflectivity data Z02 obtained in step 2, and the aircraft radar system parameter heading angle, beam width and pulse width data, calculate the extended airspace weather radar echo reflectivity data Z12 corresponding to time T1 by simulating radar scanning.

[0033] Step 4 is as follows:

[0034] Step 4.1: The polar coordinates corresponding to the position change information P(px,py,ph) at time T1 relative to time T0 are expressed as P'(R,α,β), where R is the radial distance; α is the azimuth angle; and β is the pitch angle.

[0035] Step 4.2: Calculate a sampling volume of particle scattering echoes within the range of beam distance R to R+h / 2 Among them, the radar transmission pulse width is τ, and the pulse transmission propagation distance is h;

[0036] The Cartesian coordinates corresponding to the centers of the starting and ending sections of the sampling volume in steps 4.3 and 4.2 are

[0037] Step 4.4, according to the formula Calculates the Cartesian coordinate increment produced by the beamwidth cross-section for a given elevation and azimuth angle.

[0038] Step 4.5: The sampling volume corresponding to the set point in space is approximately in the Cartesian coordinate system.

[0039]

[0040] Step 4.6: Use the results of steps 4.1 to 4.5 to simulate scanning the space weather model reflectivity data Z02 to obtain the airborne phased array weather radar extended space reflectivity factor data information Z12.

[0041] The obtained carrier position information P is combined with the obtained space weather model data Z02, as well as the carrier radar system parameters such as heading angle, beam width, pulse width, etc., and the extended airspace weather radar echo reflectivity data Z12 corresponding to time T1 is calculated by simulating the radar scanning method.

[0042] Step five is specifically as follows: the airborne phased array meteorological radar expanded airspace reflectivity factor data information Z12 obtained in step 4.6 is combined with the phased array radar actual detection airspace reflectivity echo data Z11 at time T1 to obtain the expanded airspace detection data Z13 at time T1. At the same time, the expanded airspace detection data Z13 at time T1 is transmitted to the radar screen for display.

[0043] The obtained expanded airspace reflectivity echo data Z12 is combined with the actual detection airspace reflectivity echo data Z11 of the phased array radar at time T1 to obtain the final expanded large airspace range radar plane display data Z13; at the same time, the height-range dimension data of a certain azimuth can also be obtained based on the three-dimensional contour surface grid data and displayed on the radar screen.

[0044] Specific examples of applying the embodiments of the present invention are as follows:

[0045] Assuming the aircraft is flying at an altitude of 6km, the phased array weather radar scanning range is After the airspace is expanded, the scan display range is degrees, among which The embodiments of the present invention are described in detail as follows:

[0046] At time T0, three-dimensional multi-scanning reflectivity data of the space in front of the carrier aircraft is obtained.

[0047] The modulus F of the signal data received after the active phased array weather radar completes a line scanning cycle i (Nx, Ny), where Nx and Ny represent the azimuth and range sampling points respectively, i = 1, 2...M represents the pitch layer number of the stereo scan, and M is the total pitch layer number. After conventional filtering, smoothing, and system noise elimination, the modulus value F is obtained. i '(Nx,Ny), put F i Substitute (Nx, Ny) into the weather radar equation to calculate the reflectivity factor Z i (Nx, Ny), all pitch layer reflectivity factor data are placed in a structure data, denoted as Z01.

[0048] Calculation of reflectivity data of the space weather model at time T0.

[0049] The adaptive Barnes interpolation method is used to interpolate the polar coordinates stored in the stereoscopic scanning reflectivity factor data Z01 into a regular three-dimensional Cartesian coordinate grid under the standard atmospheric refraction and earth curvature, and obtain the spatial weather model reflectivity data Z02. The basic formula of the adaptive Barnes interpolation method is:

[0050]

[0051] in,

[0052] w: represents the weight of the radar volume scan data sampling point;

[0053] r0, a0, e0: represents the coordinates of the radar volume scan data sphere, slant range, azimuth, and elevation;

[0054] r,a,e: represents the grid point sphere coordinates;

[0055] k r ,k a ,k e : represents the smoothing parameters of the Barnes interpolation method in radial, azimuth and elevation;

[0056] f a : represents the interpolated grid point data value;

[0057] f0(i): represents the reflectance value of the i-th sampling point in the relevant influence area of the reflectance value of the grid point (r, a, e);

[0058] N: represents the number of sampling points in the influence area of the reflectivity value of the grid point (r, a, e).

[0059] Calculation of the aircraft position at time T1 relative to time T0.

[0060] According to the carrier's inertial navigation position information, the carrier's position information at time T0 is recorded as (X0, Y0, H0), and the carrier's position information at time T1 is (X1, Y1, H1). Through the standard earth WGS84 coordinate system, the position P (px, py, ph) at time T1 relative to time T0 can be calculated.

[0061] Calculation of meteorological echo data of the extended airspace of the aircraft radar at T1.

[0062] The polar coordinates corresponding to the relative position P(px,py,ph) of the aircraft radar are expressed as P'(R,α,β), where R is the radial distance; α is the azimuth, the aircraft line of sight is 0°, and the values are taken from the left to the right of the aircraft line of sight. β is the pitch angle;

[0063] The radar transmit pulse width is τ, the pulse transmission propagation distance is h, and the particle scattering echo within the range of beam distance R to R+h / 2 is considered to be a sampling volume V:

[0064]

[0065] The Cartesian coordinates corresponding to the centers of the starting and ending sections of the sampling volume are:

[0066]

[0067] The Cartesian coordinate increment generated by the beam width crossing the cross section at a certain elevation angle and azimuth angle is:

[0068]

[0069] The approximate range of the sampling volume corresponding to a point in space in the Cartesian coordinate system is:

[0070]

[0071] The above calculation process is used to simulate the scanning of the extended airspace of the carrier aircraft in the space weather model data Z02, and the extended airspace reflectivity factor data information of the airborne phased array weather radar is obtained, which is recorded as Z12;

[0072] The airspace detection radar screen is displayed at time T1.

[0073] The obtained expanded airspace reflectivity echo data Z12 is combined with the actual detection airspace reflectivity echo data Z11 of the phased array radar at time T1 to obtain the final expanded large airspace range radar plane display data Z13, which can be sent to the radar screen for display. At the same time, the height-distance dimension data of a certain azimuth can also be obtained based on the three-dimensional contour surface grid data and displayed on the radar screen.

[0074] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of patent protection, should still fall within the scope of this patent. Furthermore, the technical features of the present invention may be freely combined with one another, with other technical solutions, and with other technical solutions.

Claims

1. A method for airborne active phased array weather radar airspace expansion detection and display, characterized in that: The following steps are involved: Step 1: Obtain the three-dimensional multi-layer scanning reflectivity data of the space in front of the carrier aircraft at time T0; Step 2: Calculate the reflectivity data of the space weather model at time T0; Step 3: Calculate the position change information of the carrier aircraft at time T1 relative to T0; Step 4: Calculate the weather echo data of the extended airspace of the carrier aircraft radar at time T1; Step 5: Obtain the airspace detection data after the expansion at time T1 according to the result of step 4 and display it on the radar screen; The step 1 is specifically as follows: Step 1.1: Obtain the signal data modulus value received by the active phased array weather radar after completing a line scan cycle at time T0 , where Nx and Ny represent the sampling points in azimuth and range respectively. The value range of i is 1, 2…M, where M is the total number of pitch layers. Step 1.2: Modulus value of signal data After filtering, smoothing, and system noise elimination, the modulus value is obtained , the modulus value Substitute into the weather radar equation to calculate the reflectivity factor And put all pitch layer reflectivity factor data in the same structure data middle; The step 2 is specifically as follows: By formula and formula Calculate reflectivity data of space weather model ,in, Represents the weight of the radar volume scan data sampling points; They represent the mid-range, azimuth and elevation of the radar volume scan data spherical coordinates respectively; Represents the grid point sphere coordinates; They represent the smoothing parameters of the interpolation method in radial, azimuth and elevation respectively; Represents the interpolated grid point data value; Represents grid points Reflectivity value related to the reflectivity value of the i-th sampling point in the influence area; Represents grid points The number of sampling points within the influence area of the reflectivity value.

2. The airborne active phased array weather radar airspace expansion detection and display method according to claim 1, characterized in that: The specific step three is: the latitude, longitude and altitude of the carrier position information is (X0, Y0, H0), and the latitude, longitude and altitude of the carrier position information at time T1 is (X1, Y1, H1). The position change information at time T1 relative to time T0 can be calculated using the standard earth WGS84 coordinate system. .

3. The method for airborne active phased array weather radar airspace expansion detection and display according to claim 2, characterized in that: The step four is: Using the position change information at time T1 relative to time T0 obtained in step 3, combined with the spatial weather model reflectivity data obtained in step 2 , as well as the aircraft radar system parameters heading angle, beam width and pulse width data, and calculate the extended airspace weather radar echo reflectivity data corresponding to time T1 by simulating radar scanning. .

4. The airborne active phased array weather radar airspace expansion detection and display method according to claim 3, characterized in that: The step 4 is specifically as follows: Step 4.1: Position change information at time T1 relative to time T0 The corresponding polar coordinates are expressed as ,in is the radial distance; is the azimuth, is the pitch angle; Step 4.2: Calculate beam distance arrive A sampling volume of particle scattering echoes within the range ,in, is the radar transmit pulse width, is the pulse transmission propagation distance; The Cartesian coordinates corresponding to the centers of the starting and ending sections of the sampling volume in steps 4.3 and 4.2 are 、 ; Step 4.4, according to the formula Calculate the Cartesian coordinate increment of the beam width cross-section when setting the elevation and azimuth angles; Step 4.5: The sampling volume corresponding to the set point in space is approximately in the Cartesian coordinate system. 、 、 ; Step 4.6: Use the results from steps 4.1 to 4.5 to analyze the reflectivity data of the space weather model. Perform a simulated scan to obtain the extended airspace reflectivity factor data of the airborne phased array weather radar .

5. The airborne active phased array weather radar airspace expansion detection and display method according to claim 4, characterized in that: Use the airborne phased array weather radar expanded spatial reflectivity factor data information obtained in step 4.6 Compared with the actual detection airspace reflectivity echo data of the phased array radar at time T1 Combine and obtain the expanded spatial detection data at time T1 At the same time, the spatial detection data after the expansion of time T1 Transmitted to the radar screen for display.

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