A Route Planning Method for Measuring Radiation Characteristics of a Moving Platform Phased Array Radar

Abstract

The radiation characteristics of a phased array radar are the spatio-temporal distribution characteristics of the radar transmission power, which are related to the combat and technical capabilities of the radar to detect targets. Traditional measurement methods are mainly used for static tests. When measuring the radiation characteristics of a phased array radar on a moving platform, due to the characteristics of its array surface system and beam arrangement, it is often necessary to customize the measurement method in combination with the specific detection scenario and environmental characteristics, and carry out measurement path planning. The above traditional measurement methods are no longer applicable. The present invention proposes a method for measuring route planning of the radiation characteristics of a phased array radar on a moving platform. Aiming at the transmission characteristics during the detection of the phased array radar, an unmanned aerial vehicle (UAV) is used to carry an electromagnetic radiation receiving device. According to the expected movement path of the radar under test in the test scenario, the prior spatio-temporal distribution of the radar radiation characteristics is obtained. Under the constraints of the flight boundary conditions of the UAV and the boundary conditions of the electromagnetic radiation receiving device, the measurement positions and measurement duration of the radiation characteristics are determined, and the UAV flight route is designed to cover all measurement positions and meet the measurement duration.

Description

Technical Field

[0001] The present invention belongs to the field of radar performance inspection, and particularly relates to a method for measuring route planning of radiation characteristics of a phased array radar based on a moving platform. Background Art

[0002] The phased array radar technology was proposed in the 1930s of the last century. Its good effects have promoted the rapid development of phased array radars. At present, phased array radars have become the development direction of radar systems by virtue of advantages such as fast beam scanning, excellent anti-interference performance, strong multi-functional and multi-tasking capabilities, and high system reliability. The radiation characteristics of a phased array radar are the spatio-temporal distribution characteristics of the radar transmitting power, which are related to the combat and technical capabilities of the radar to detect targets. Traditional measurement methods are mainly used for static tests. When measuring the radiation characteristics of a phased array radar on a moving platform, due to the characteristics of its array surface system and beam arrangement, it is often necessary to customize the measurement method in combination with the specific detection scenario and environmental characteristics, and perform measurement path planning. The above traditional measurement methods are no longer applicable. In recent years, measurement technologies based on unmanned aerial vehicles (UAVs) have gradually been applied to the test of the receiving pattern of a radar array surface. However, there is still little research on the method for measuring the radiation characteristics of a phased array radar on a moving platform using a UAV. Especially for the measurement route planning method in the case of platform movement and normal detection scenarios of phased array radars, it needs to be specifically designed according to the transmitting characteristics during the detection of phased array radars and the boundary conditions of UAV measurements, and further research is still needed. Summary of the Invention

[0003] The present invention overcomes the shortcomings in the prior art and proposes a method for measuring route planning of radiation characteristics of a phased array radar based on a moving platform. In view of the transmitting characteristics during the detection of phased array radars, a UAV is used to load an electromagnetic radiation receiving device. According to the expected movement path of the radar under test in the test scenario, the prior spatio-temporal distribution of the radar radiation characteristics is obtained. Under the constraints of the flight boundary conditions of the UAV and the boundary conditions of the electromagnetic radiation receiving device, the measurement positions and measurement duration of the radiation characteristics are determined, and the UAV flight route is designed to cover all measurement positions and meet the measurement duration. Specifically:

[0004] Step (1): According to the test scenario, determine the expected movement path of the phased array radar under test, and obtain the prior information of the longitude lon b , latitude lat b , and altitude h b ;

[0005] Step (2): According to the detection airspace of the phased array radar under test in the test scenario, determine the airspace where radiation characteristics need to be measured, and according to the wave position arrangement law of the transmitting beams in this airspace and the prior information of the radar, divide the airspace into different sub-airspaces, and determine the minimum lobe distribution period of each sub-airspace: in the azimuth dimension, the minimum lobe distribution period is obtained as △BW Az; In the pitch dimension, the minimum lobe distribution period △BW is obtained El ;

[0006] Step (3): According to the spatial sampling theorem, calculate the azimuth sampling interval and pitch sampling interval of the UAV relative to the phased array radar in the airspace to be measured;

[0007] Step (4): Determine the azimuth sampling angle and pitch sampling angle according to the angle sampling interval of the airspace to be measured, and obtain the sampling angles of each sampling point;

[0008] Step (5): Determine the maximum sampling distance, minimum sampling distance, and sampling distance of each sampling point of the UAV relative to the phased array radar;

[0009] Step (6): Determine the sampling height of each sampling point of the UAV according to the height of the phased array radar;

[0010] Step (7): Calculate the coordinate values of the position of the UAV relative to the phased array radar in the geographical coordinate system according to the sampling angles and sampling distances of each sampling point of the UAV;

[0011] Step (8): Calculate the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system according to the position of the radar and the position of the UAV relative to the radar;

[0012] Step (9): Calculate the longitude, latitude, and height of each sampling point of the UAV according to the sampling height and the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system;

[0013] Step (10): Determine the sampling duration of each sampling point of the UAV according to the number of samples and the sampling interval;

[0014] Step (11): Set and form the flight route of the UAV according to the longitude, latitude, height, and sampling duration of each sampling point of the UAV, and complete the flight route planning for measuring the radiation characteristics of the moving platform phased array radar.

[0015] Furthermore, in the low-angle region, due to lobe splitting, it is necessary to select the minimum lobe distribution period △BW of interest in the pitch dimension according to the characteristics of the split lobes El .

[0016] Furthermore, in step (3), the azimuth sampling interval △θ Az and the pitch sampling interval △θ El are specifically as follows:

[0017]

[0018] where k Az and k ElThe sampling factor is generally taken as 1 / 2 to 1 / 5. When the lobe distribution angular periods in different airspaces are different, different sampling intervals are designed accordingly.

[0019] Further, in step (4), the azimuth sampling angle θ Az and the elevation sampling angle θ El are determined, and the sampling angles (θ Az θ El ) of each sampling point are obtained, specifically as follows:

[0020]

[0021] Among them, θ Az0 is the initial azimuth sampling angle, and θ El0 is the initial elevation sampling angle.

[0022] Further, in step (5), the maximum sampling distance R max and the minimum sampling distance R min of each sampling point of the UAV relative to the phased array radar are determined, and the sampling distance R is specifically as follows:

[0023]

[0024] Among them, P t is the peak power of radar transmission, G t is the transmission gain of the radar, G i is the receiving gain of the electromagnetic radiation detection device, λ is the radar wavelength, L s is the system loss, S i is the sensitivity of the detection device, D i is the dynamic range of the detection device, k R is the proportionality factor, generally taken as 1 / 2.

[0025] Further, in step (6), the sampling height H of each sampling point of the UAV is determined specifically as follows:

[0026]

[0027] Among them, h is the radar height, r e is the equivalent earth radius, r e = 4r 0 / 3, and the earth radius r 0 is taken as 6367.444 km.

[0028] Further, in step (7), according to the sampling angles (θ Az θ El ) and the sampling distance R of each sampling point of the UAV, the coordinate values of the position of the UAV relative to the phased array radar in the geographic coordinate system are calculated specifically as follows:

[0029]

[0030] Further, in step (8), according to the position of the radar and the position of the UAV relative to the radar, calculate the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system Specifically:

[0031]

[0032] Among them, the radius of curvature of the earth's meridian The eccentricity of the earth R e is the semi-major axis of the earth, and R p is the semi-minor axis of the earth.

[0033] Further, in step (9), calculate the longitude lon r , latitude lat r , and altitude h r Specifically:

[0034]

[0035] Among them, the radius of curvature of the earth's meridian

[0036] Further, in step (10), the specific sampling duration T of each sampling point of the UAV is determined as:

[0037] T = N·Δt (8)

[0038] N is the number of samples, generally taking more than 5, and the sampling interval Δt generally takes the scanning period of the measured phased array radar beam at the current position.

[0039] The beneficial effects of the present invention are as follows:

[0040] (1) The present invention first proposes a flight path planning method for measuring the electromagnetic radiation characteristics of phased array radars by UAVs, and fully considers the electromagnetic radiation characteristics of phased array radars and their prior distributions, the boundary conditions of UAV flight, and the boundary conditions of electromagnetic radiation receiving equipment;

[0041] (2) The flight path planning method described in the present invention is applicable to the measurement of the radiation characteristics of various moving platform phased array radars, especially applicable to the measurement scenario of radar radiation characteristics under the normal detection of the radar and the normal movement of the platform where the radar is located, such as the measurement scenario of the radiation characteristics when detecting moving vehicle-mounted phased array radars and shipborne phased array radars, etc. Description of the Drawings

[0042] Figure 1 It is a schematic diagram of the measurement flight path planning

[0043] Figure 2For the measurement route planning flowchart

[0044] Figure 3 For the measurement route planning embodiment (sampling angle) Specific implementation manner

[0045] The present invention will be further described in detail below with reference to the accompanying drawings:

[0046] (1) According to the test scenario plan, a certain vehicle-mounted phased array radar moves northward in the desert along a straight path, and the longitude lon b , latitude lat b , altitude h b and other prior information are known.

[0047] (2) The array surface of this type of vehicle-mounted phased array radar is fixed relative to the vehicle body. Using the two-dimensional phase scanning search mode, the detection airspace is azimuth 135 - 225°, elevation 3 - 30°, and the radiation characteristics of this airspace are measured. The radar transmitting beams are arranged according to the geographic coordinate system. Since the beam width increases and the gain decreases when the phased array radar beam deviates from the normal direction of the array surface, the beam arrangement intervals near the normal direction of the array surface and near the edge of the array surface are different, and the minimum lobe distribution period △BW Az in the azimuth dimension is 3°, and the minimum lobe distribution period △BW El in the elevation dimension is 3°, excluding the low-angle region without lobe splitting;

[0048] (3) According to the following formula calculation, the azimuth sampling interval △θ Az of the rotor unmanned aerial vehicle relative to the phased array radar in the airspace to be measured is 1°, and the elevation sampling interval △θ El is 1°.

[0049]

[0050] (4) According to the angle sampling interval of the airspace to be measured, the possible azimuth sampling angles θ Az and elevation sampling angles θ El are determined. The azimuth sequences of 3 elevation angles (5°, 15°, 25°) and the elevation sequences of 3 azimuth angles (145°, 180°, 215°) are sampled key points, forming a three-horizontal and three-column sampling grid, as shown in Figure 3 , and the sampling angle combinations (θ Az θ El ) of each sampling point are obtained as follows, with a total of 357 sampling points:

[0051]

[0052] (5) Determine the maximum sampling distance R max and the minimum sampling distance R of each sampling point of the rotor unmanned aerial vehicle relative to the phased array radarmin , finally, the sampling distance R is obtained as 2 km.

[0053]

[0054] Among them, P t is the peak power of radar transmission, G t is the transmission gain of the radar, G i is the receiving gain of the electromagnetic radiation detection device, λ is the radar wavelength, L s is the system loss, S i is the sensitivity of the detection device, D i is the dynamic range of the detection device, k R is the proportionality factor, and here it is taken as 1 / 2.

[0055] (6) Determine the sampling height H of each sampling point of the rotor UAV according to the following formula. It is known that the minimum flight height H min of the rotor UAV is 10 m, and the maximum flight height H max is 3000 m. In this example, the sampling height range is 107 - 1002 m, within the flight height range of the UAV.

[0056]

[0057] Among them, h is the radar height of 2 m, r e is the equivalent earth radius, r e = 4r 0 / 3, and the earth radius r 0 is taken as 6367.444 km.

[0058] (7) According to the sampling angles (θ Az θ El ) and the sampling distance R of each sampling point of the rotor UAV, calculate the values of the position of the UAV relative to the phased array radar in the geographic coordinate system:

[0059]

[0060] (8) According to the position of the radar and the position of the UAV relative to the radar, calculate the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system

[0061]

[0062] Among them, the radius of curvature of the earth's meridian The eccentricity of the earth R e is the semi-major axis of the earth, R p is the semi-minor axis of the earth.

[0063] (9) Calculate the longitude lon of each sampling point of the rotary-wing UAV r , latitude lat r , altitude h r :

[0064]

[0065] Among them, the radius of curvature of the earth's meridian

[0066] (10) According to the following formula, the sampling duration T of each sampling point of the rotary-wing UAV is 5 s.

[0067] T = N·Δt (8)

[0068] Among them, N is the number of samples, which is taken as 5 in this example, and the sampling interval Δt is taken as the scanning period of the measured phased array radar beam at the current position, which is 1 s in this example.

[0069] (11) According to the longitude, latitude, altitude and sampling duration of each sampling point of the rotary-wing UAV, set and form the UAV flight route, and complete the flight route planning for measuring the radiation characteristics of the phased array radar on the moving platform.

[0070] The present invention is not limited to the above specific embodiments, and the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made according to the technical essence of the present invention to the above embodiments shall be included in the protection scope of the present invention.

Claims

1. A method for flight path planning for measuring the radiation characteristics of a phased array radar on a moving platform, characterized in that: Step (1): Determine the expected movement path of the phased array radar under test according to the test scenario, and obtain the prior information of the longitude lon b , latitude lat b , and altitude h b of the sampling points; Step (2): Determine the airspace where radiation characteristics need to be measured according to the detection airspace of the phased array radar under test in the test scenario, and divide the airspace into different sub-airspaces according to the wave position arrangement law of the transmitting beam in the airspace and the prior information of the radar, and determine the minimum lobe distribution period of each sub-airspace: In the azimuth dimension, the minimum lobe distribution period is obtained as △BW Az ; In the elevation dimension, the minimum lobe distribution period is obtained as △BW El ; Step (3): According to the spatial sampling theorem, calculate the azimuth sampling interval and the pitch sampling interval of the unmanned aerial vehicle (UAV) relative to the phased array radar in the airspace to be measured; Step (4): Determine the azimuth sampling angle and the pitch sampling angle according to the angle sampling interval of the airspace to be measured, and obtain the sampling angles of each sampling point; Step (5): Determine the maximum sampling distance, the minimum sampling distance, and the sampling distance of each sampling point of the UAV relative to the phased array radar; Step (6): Determine the sampling height of each sampling point of the UAV according to the height of the phased array radar; Step (7): Calculate the coordinate values of the position of the UAV relative to the phased array radar in the geographic coordinate system according to the sampling angles and sampling distances of each sampling point of the UAV; Step (8): Calculate the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system according to the position of the radar and the position of the UAV relative to the radar; Step (9): Calculate the longitude, latitude, and height of each sampling point of the UAV according to the sampling height and the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system; Step (10): Determine the sampling duration of each sampling point of the UAV according to the number of samples and the sampling interval; Step (11): Set and form the flight path of the UAV according to the longitude, latitude, height, and sampling duration of each sampling point of the UAV, and complete the flight path planning for measuring the radiation characteristics of the phased array radar on the moving platform; Determine the azimuth sampling angle θ in the step (4) Az and the pitch sampling angle θ El , and obtain the sampling angles (θ Az θ El ) of each sampling point, specifically as follows: Among them, θ Az0 is the initial azimuth sampling angle, and θ El0 is the initial pitch sampling angle; Determine the maximum sampling distance R of each sampling point of the UAV relative to the phased array radar in step (5) max and the minimum sampling distance R min , and the specific sampling distance R is as follows: Among them, P t is the peak power of radar transmission, G t is the transmission gain of radar, G i is the receiving gain of the electromagnetic radiation detection device, λ is the radar wavelength, L s is the system loss, S i is the sensitivity of the detection device, D i is the dynamic range of the detection device, k R is the proportionality factor; In step (7), according to the sampling angles (θ Az θ El ) and sampling distances R of each sampling point of the UAV, the coordinate values of the position of the UAV relative to the phased array radar in the geographic coordinate system are calculated specifically as follows: In step (8), according to the position of the radar and the position of the UAV relative to the radar, calculate the coordinate values of each sampling point of the UAV in the geocentric fixed coordinate system Specifically: Among them, the radius of curvature of the earth's meridian The eccentricity of the earth R e is the semi-major axis of the earth, and R p is the semi-minor axis of the earth; In step (9), calculate the longitude lon of each sampling point of the drone r , latitude lat r , and altitude h r Specifically: wherein, the radius of curvature of the earth's meridian 2. The method for flight path planning for measuring the radiation characteristics of a phased array radar on a moving platform according to claim 1, characterized in that: In the low-angle region, due to lobe splitting, it is necessary to select the minimum lobe distribution period △BW of the elevation dimension of interest according to the characteristics of the split lobes El .

3. The method for flight path planning for measuring the radiation characteristics of a phased array radar on a moving platform according to claim 1, characterized in that: Calculate the azimuth sampling interval △θ in step (3) Az and the pitch sampling interval △θ El Specifically: Among them, k Az and k El are sampling factors, generally taking values from 1 / 2 to 1 / 5.

4. The method for flight path planning for measuring the radiation characteristics of a phased array radar on a moving platform according to claim 1, characterized in that: In step (6), the specific method for determining the sampling height H of each sampling point of the UAV is as follows: where h is the radar altitude, and r e is the equivalent earth radius, and r e = 4r 0 / 3, and the earth radius r 0 is taken as 6367.444 km.

5. The method for flight path planning for measuring the radiation characteristics of a phased array radar on a moving platform according to claim 1, characterized in that: In step (10), the specific method for determining the sampling duration T of each sampling point of the UAV is as follows: T = N·Δt (8) where N is the number of samples, and the sampling interval Δt is the scanning period of the beam of the phased array radar to be measured at the current position.

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