[0058] The preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The accompanying drawings constitute a part of the application and are used together with the embodiments of the present invention to explain the principle of the present invention, and are not used to limit the scope of the present invention.
[0059] Such as figure 1 As shown, when the target is in the near zone or over the headspace, the target that should have directly crossed the headspace of the station is displayed on the radar terminal. Due to the angle measurement and ranging error, an arc-shaped trajectory bypasses the station. This problem is caused by two errors, the angle measurement error and the ranging error; the angle measurement error is caused by different OBA (OffBoresight Angle) meters caused by the inconsistent antenna elevation in different airspaces; the ranging error is the measured distance The slope distance is caused by the introduction of height.
[0060] In the specific embodiment 1 of the present invention, a method for determining the azimuth and distance when a target crosses the headspace is disclosed to solve the above-mentioned problems, such as figure 2 As shown, including the following steps:
[0061] Step S1: Obtain the erection height H1 of the secondary radar antenna of the site and the normal azimuth A of the radar antenna; the erection height can be input by GPS/Beidou or manually.
[0062] Step S2: Receive the secondary radar response pulse signal through the antenna, and calculate the target height H2, the distance R1 (slant distance) between the target and the radar antenna, and the current amplitude difference of the sum and difference channels;
[0063] Step S3: Obtain the elevation angle of the current antenna beam and the straight-line true distance between the target and the radar antenna according to the erection height of the secondary radar antenna of the local station H1, the target height H2, and the distance R1 between the target and the radar antenna; image 3 Shown:
[0064] The difference ΔH between the target height and the antenna height of the site:
[0065] ΔH=H2-H1 (1)
[0066] According to the trigonometric function sinθ=ΔH/R1, get the elevation angle θ of the current antenna beam:
[0067]
[0068] The straight-line true distance R between the target and the radar antenna:
[0069] R=R1×cosθ (3);
[0070] Step S4: According to the elevation angle θ of the current antenna beam, call the corresponding OBA table, according to the current and difference channel amplitude difference, query the OBA table to obtain the current target's azimuth deviation from the normal value ΔA (that is, the OBA angle measurement obtained Offset value);
[0071] Step S5: Determine the current target's azimuth F according to the normal azimuth A of the local radar antenna and the deviation of the current target's azimuth from the normal value ΔA:
[0072] F=A+ΔA (4).
[0073] Before performing the steps of the present invention, a plurality of OBA tables are divided according to different antenna beam elevation angle ranges, and the specific implementation method is as follows:
[0074] Obtain OBA tables under different antenna beam elevation angles through darkroom testing, or obtain response signals from the airspace through the secondary radar equipment running for sufficient time to learn and generate OBA tables under different antenna beam elevation angles, or manually edit OBA data according to theory , Generate OBA tables under different antenna beam elevation angles.
[0075] The OBA tables under different antenna beam elevation angles are injected into the secondary radar equipment through the radar terminal, which is used to select the corresponding OBA table according to the beam elevation angle of the current antenna actually working to determine the target's azimuth deviation from the normal value.
[0076] Compared with the prior art, the method for determining the azimuth and distance when the target passes the headspace provided by this embodiment adopts different processing methods for the above two errors: (1) Using the airspace pitch OBA division method for the angle measurement error , Using OBA meters under different antenna beam elevation angles to improve the accuracy of the secondary radar's angle measurement when passing the headspace; (2) The range-finding projection method is used for the range error to ensure the true distance and the radar terminal in the near zone and the headspace The display distance is the same.
[0077] Such as Figure 4 with Figure 5 As shown, if the amplitude difference between the response signal and the difference channel of a certain query is 6dB; the original method is used and only one OBA meter is used, then only Figure 4 Perform angle measurement, and the measured offset angle ΔA=0.62 degrees; using the method in the present invention, the OBA table at the corresponding pitch angle will be used according to the target pitch, and the target will be used in the far area Figure 4 Measure the angle, the measured offset angle ΔA=0.62°, if the target is over the headspace, use Figure 5 The angle measurement is performed, and the measured offset angle ΔA=10.22°; the accuracy of angle measurement in the near area is improved by 9.6° by using this method.
[0078] In the second embodiment of the present invention, there is provided a device for determining the position and distance of the target when it passes the headspace, such as Image 6 As shown, it includes a radar antenna, a receiver module, a signal processing module, and a radar terminal, among which,
[0079] The radar antenna is used to radiate electromagnetic signals into space and receive secondary radar response pulse signals;
[0080] The receiver module is used to receive the secondary radar response pulse signal, after limiting, filtering, mixing, amplifying, and forming a digital signal after AD sampling, and calculating the target height, target and secondary radar antenna from it The distance between the current and the channel and the difference channel amplitude, phase data;
[0081] The signal processing module is configured to obtain the elevation angle of the current antenna beam and the straight-line true distance between the target and the radar antenna according to the erection height of the secondary radar antenna of the local station, the target height, and the distance between the target and the radar antenna; It is also used to call the corresponding OBA table according to the elevation angle of the current antenna beam, and obtain the current target’s azimuth deviation from the normal value by querying the OBA table according to the current and difference channel amplitude difference; The normal bearing and the bearing of the current target deviate from the normal value to determine the bearing of the current target.
[0082] The radar terminal is used to display the true straight-line distance between the target and the radar antenna and the azimuth of the current target, and is also used to generate an OBA table, and load the OBA table to the signal processing module.
[0083] Preferably, the signal processing module further stores a plurality of OBA tables, the plurality of OBA tables are divided according to different antenna beam elevation angle ranges, so as to select the corresponding OBA table according to the measured antenna beam elevation angle to determine the target The bearing deviates from the normal value.
[0084] Preferably, in the signal processing module, the following operations are specifically performed to obtain the elevation angle of the current antenna beam:
[0085] Obtain the difference ΔH between the target height and the height of the site:
[0086] ΔH=H2-H1 (5)
[0087] Among them, H1 is the erection height of the secondary radar antenna of this station, and H2 is the target height;
[0088] According to the trigonometric function sinθ=ΔH/R1, get the elevation angle θ of the current antenna beam:
[0089]
[0090] Among them, R1 is the distance between the target and the radar antenna.
[0091] Preferably, in the signal processing module, the following operations are specifically performed to determine the orientation F of the current target:
[0092] F=A+ΔA (7)
[0093] Among them, A is the normal azimuth of the radar antenna of the station, and ΔA is the deviation of the current target's azimuth from the normal.
[0094] Preferably, in the signal processing module, the following operations are specifically performed to obtain the straight-line true distance R between the target and the radar antenna:
[0095] R=R1×cosθ (8)
[0096] The present invention provides a brand-new method and optimization device for processing targets over the headspace, including but not limited to systems such as secondary radars or primary radars. The technology requires simple equipment topology, low implementation cost, and fully automatic operation. Without any manual intervention, it can automatically adapt to the whole airspace pitch and omni-directional target processing requirements, especially to improve the angle and range measurement capabilities of headspace targets, and provide reliable targets for radar operators/air traffic control commanders Information, effectively guarantee flight safety. Its deformation methods such as radar being mounted on an airplane, and the processing method for the probing of sea targets or ground targets are also included in the present invention.
[0097] The foregoing method embodiments and device embodiments are based on the same principle, and their correlations can be used for reference from each other, and the same technical effects can be achieved.
[0098] Those skilled in the art can understand that all or part of the procedures for implementing the methods in the above-mentioned embodiments can be implemented by a computer program instructing relevant hardware, and the program can be stored in a computer-readable storage medium. Wherein, the computer-readable storage medium is a magnetic disk, an optical disk, a read-only storage memory or a random storage memory, etc.
[0099] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or changes within the technical scope disclosed by the present invention. All replacements shall be covered within the protection scope of the present invention.
