Search wave position calculation method under interference indication

Abstract

The application discloses a search wave position calculation method under interference indication, comprising the following steps: S1, obtaining relevant data and initializing relevant parameters; S2, calculating the azimuth and pitch wave position data of the near-boundary and far-boundary points of a search space; and S3, arranging wave positions and performing beam coverage on the space of the line connecting the two wave positions of the near-boundary and the far-boundary. The application is applicable to the specific scene of a target+tracking radar dual station in a weapon system, and utilizes geometric principles to reduce the number of search wave positions required by a tracking radar for interference detection after receiving interference indication of a target radar.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and in particular to a method for calculating search wave position under interference indication. Background Technology

[0002] In air defense and anti-missile weapon systems, a low-precision radar is generally used for search and target designation. This low-precision radar is called the target designation radar or search radar. After the target is detected and confirmed, the target coordinate information is assigned to another high-precision radar, which is called the tracking radar. This process is called target designation.

[0003] In complex electromagnetic environments, target-finding radars may be subject to defensive noise suppression interference, rendering them unable to detect targets and only able to passively track the interference source. In this situation, only the azimuth and elevation angles of the interference source are obtained, and ranging is not possible. In this case, the information from tracking the interference source is assigned to the tracking radar, a process known as interference indication. Since only azimuth and elevation information are available, and range information is lacking, coordinate transformation and target-finding search are impossible. It can be assumed that the target may be within all detectable range segments in the indicated azimuth and elevation. If the two radars are far apart, the tracking radar must sequentially cover all possible airspace ranges relative to the azimuth and elevation directions given by the target-finding radar with its beam. A conventional calculation method involves projecting several range segments along the direction of the interference indication from the target-finding radar according to the beamwidth, performing coordinate transformation on the center distance point of each range segment to obtain the azimuth and elevation information relative to the tracking radar, such as... Figure 1 As shown. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a method for calculating search wave positions under interference indication. Specifically for the dual-station scenario of target indicator + tracking radar in a weapon system, this method utilizes geometric principles to reduce the number of search wave positions required for the tracking radar to perform interference detection after receiving interference indication from the target indicator radar.

[0005] To achieve the aforementioned objectives of the invention, the technical solution adopted to solve its technical problems is as follows: A method for calculating search wave position under jamming indication, employing at least two radar systems, where the information indicated by one target radar to the other tracking radar only includes azimuth and elevation information, but not range information. The calculation method specifically includes the following steps: Step S1: Obtain relevant data and initialize relevant parameters; Step S2: Calculate the azimuth and elevation position data of the near and far boundary points of the search airspace; Step S3: Arrange the beam positions and perform beam coverage on the airspace connecting the near and far boundary beam positions.

[0006] Furthermore, the relevant data acquired in step S1 includes: the azimuth of the tracking radar in the target radar coordinate system, the azimuth and elevation of the interference target indicated by the target radar, and the distance between the two radars.

[0007] Furthermore, the initialization parameters in step S1 are: the tracking radar target's maximum and minimum search distances.

[0008] Furthermore, the method for calculating the azimuth and elevation potential data of the near and far boundary points of the search airspace in step S2 is as follows: Calculate the azimuth angle A1 of the near-boundary scan boundary and the azimuth angle A2 of the far-boundary scan boundary: Calculate the angle α = Af - At between the target and the F radar relative to the S radar; Calculate the azimuth scan range θ: γ = asin(c*sinα / a); ε = asin(c*sinα / r); θ = γ - ε; Calculate the azimuth angle A1 of the near-boundary scan endpoint: β = α + γ; A1=Af-β; if A1<0, then +360°; Calculate the azimuth angle A2 of the far-boundary scan endpoint: ω = α + ε; A2 = Af - ω; if A2 < 0, then +360°; Calculate the near-boundary scan boundary pitch angle E1 and the far-boundary scan boundary pitch angle E2: If |α|=0, then: b = a + c; d = r + c; If |α|=180°, then: b=ac; d=rc; otherwise: b = a*sin(180-β) / sinα; d = r*sin(180-ω) / sinα; Calculate the near-boundary height h1 = b * tgEt; Calculate the far boundary height h2 = d * tgEt; Calculate the near-boundary pitch E1 = ctg(h1 / a); Calculate the far-bound pitch E2 = ctg(h2 / r); Obtain the near boundary (A1, E1) and far boundary (A2, E2) of the scan range.

[0009] By employing the above technical solutions, this invention has the following advantages and positive effects compared with the prior art: This invention improves the calculation method of search wave positions under jamming indication. For the specific scenario of dual-station target + tracking radar in weapon system, it uses geometric principles to reduce the number of search wave positions required for the tracking radar to perform jamming detection after receiving jamming indication from the target radar. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the search waveform under interference indication; Figure 2 This is a flowchart of a search wave position calculation method under interference indication according to the present invention; Figure 3 This is a schematic diagram of the planar coordinate system in this invention; Figure 4 This is a schematic diagram of the three-dimensional coordinate system in this invention; Figure 5 This is a schematic diagram of the search wave position scanning coverage between boundary points in this invention. Detailed Implementation

[0011] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0012] like Figure 2 As shown, this embodiment discloses a method for calculating the search beam position under interference indication. The system employs at least two radars. The information indicated by one target radar to the other tracking radar only includes azimuth and elevation information, but no range information. The calculation method specifically includes the following steps: Step S1: Obtain relevant data and initialize relevant parameters; Step S2: Calculate the azimuth and elevation position data of the near and far boundary points of the search airspace; Step S3: Arrange the beam positions and perform beam coverage on the airspace connecting the near and far boundary beam positions.

[0013] In this embodiment, the position of the target radar is represented by point S, and the position of the tracking radar is represented by point F. A planar polar coordinate system is established with point S as the origin and the line connecting S and F as the baseline. ST represents the furthest distance searched by radar F, denoted as r, and the closest distance as a. The distance between radars S and F is c. Concentric circles are drawn with radar F as the center and r and a as radii. T represents the projection of the farthest point of the target onto the ground, and T' represents the projection of the nearth point of the target onto the ground. The angle ∠TSF between TS and SF is defined as α, which is the target entry azimuth angle. ∠TFT' is defined as θ, which is the angular range that radar F needs to scan in the azimuth. The median of θ is the ideal antenna normal of radar F. After the distance of SF is fixed and the search range of F is determined, θ is only related to α. The planar coordinate system is as follows: Figure 3 , three-dimensional coordinate system, such as Figure 4 .

[0014] Using the law of sines, given a, c, and α, the azimuth of the near-boundary point wave position and the far-boundary point wave position can be calculated.

[0015] The elevation of the near-boundary and far-boundary wave positions can be calculated using the tangent formula.

[0016] The specific calculation method is as follows: Step S1 involves acquiring relevant data and initializing parameters. The acquired data includes: the distance c between radars S and F, the azimuth Af of radar F in the S coordinate system, and the azimuth At and elevation Et of the interference target indication given by radar S. The initialization parameters are: the farthest search range r and the closest search range a of radar F.

[0017] The method for calculating the azimuth and elevation position data of the near and far boundary points of the search airspace in step S2 is as follows: Calculate the azimuth angle A1 of the near-boundary scan boundary and the azimuth angle A2 of the far-boundary scan boundary: Calculate the angle α = Af - At between the target and the F radar relative to the S radar; Calculate the azimuth scan range θ: γ = asin(c*sinα / a); ε = asin(c*sinα / r); θ = γ - ε; Calculate the azimuth angle A1 of the near-boundary scan endpoint: β = α + γ; A1=Af-β; if A1<0, then +360°; Calculate the azimuth angle A2 of the far-boundary scan endpoint: ω = α + ε; A2 = Af - ω; if A2 < 0, then +360°; Calculate the near-boundary scan boundary pitch angle E1 and the far-boundary scan boundary pitch angle E2: If |α|=0, then: b = a + c; d = r + c; If |α|=180°, then: b=ac; d=rc; otherwise: b = a*sin(180-β) / sinα; d = r*sin(180-ω) / sinα; Calculate the near-boundary height h1 = b * tgEt; Calculate the far boundary height h2 = d * tgEt; Calculate the near-boundary pitch E1 = ctg(h1 / a); Calculate the far-bound pitch E2 = ctg(h2 / r); Obtain the near boundary (A1, E1) and far boundary (A2, E2) of the scan range.

[0018] In step S3, wave positions are arranged, and beam scanning coverage is performed on the spatial domain connecting the near boundary (A1, E1) and far boundary (A2, E2) wave positions. Figure 5 Here, the conventional wavelet arrangement rules can be used. Note that this diagram is only a schematic diagram. The left, right, up, and down positions of the near boundary (A1, E1) and the far boundary (A2, E2) are greatly related to the calculated data and parameters. The two points may be very close and can be covered by only one wavelet, or they may be far apart and multiple beams need to be inserted in between.

[0019] Example: Since the data and parameters in this method can vary, the invention will be described using specific data and parameters in a particular scenario: Step S1: Acquire relevant data and initialize parameters. The acquired data includes: distance between radars S and F, c = 5km; azimuth of radar F in the S coordinate system, Af = 90°; and azimuth of the interference target indication given by radar S, At = 30° and Et = 30°. Initialization parameters are: maximum target search distance of radar F, r = 60km; minimum target search distance, a = 10km.

[0020] Step S2: Calculate the azimuth and elevation potential data of the near and far boundaries of the search airspace. The calculation steps are as follows: Calculate the azimuth angle A1 of the near-boundary scan boundary and the azimuth angle A2 of the far-boundary scan boundary: Calculate the angle α between the target and radar F relative to radar S: α = Af - At = 60°. Calculate the azimuth scan range θ: γ=asin(c*sinα / a)=asin(5*sin60 / 10)=25.66°; ε= asin(c*sinα / r)=asin(5*sin60 / 60)=4.14°; θ = γ - ε = 21.52°; Calculate the azimuth angle A1 of the near-boundary scan endpoint: β = α + γ = 60 + 25.66 = 85.66°; A1 = Af - β = 90 - 85.66 = 4.34°; Calculate the azimuth angle A2 of the far-boundary scan endpoint: ω = α + ε = 60 + 4.14 = 64.14°; A2 = Af - ω = 90 - 64.14 = 25.86; Calculate the near-boundary scan boundary pitch angle E1 and the far-boundary scan boundary pitch angle E2: b= a*sin(180-β) / sinα=10*sin(180-85.66) / sin60=11.51km; d= r*sin(180-ω) / sinα=60*sin(180-64.14) / sin60=62.344km; The near-boundary height h1 is calculated as h1 = b * tgEt = 11.51 * tg30 = 6.6453 km; Calculate the altitude at the far boundary: h2 = d * tgEt = 62.344 * tg30 = 35.9943 km; Calculate the near-boundary pitch E1 = ctg(h1 / a) = ctg(6.6453 / 10) = 33.61°; Calculate the far-boundary pitch E2 = ctg(h2 / r) = ctg(35.9943 / 60) = 30.96°; The near boundary (4.34°, 33.61°) and far boundary (25.86°, 30.96°) of the scan range were obtained.

[0021] Step S3: Perform beam positioning and beam scan coverage of the airspace connecting the near boundary (4.34°, 33.61°) and far boundary (25.86°, 30.96°). The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for calculating search wave position under interference indication, comprising a system of two radars, wherein the information indicated by one target radar to the other tracking radar only includes azimuth and elevation information, without range information, characterized in that, The calculation method specifically includes the following steps: Step S1: Obtain relevant data and initialize relevant parameters; The relevant data acquired in step S1 includes: the azimuth of the tracking radar in the target radar coordinate system, the azimuth and elevation of the interference target indicated by the target radar, and the distance between the two radars. The initialization parameters in step S1 are: the tracking radar target's maximum search distance and the nearest search distance; Step S2: Calculate the azimuth and elevation position data of the near and far boundary points of the search airspace; The method for calculating the azimuth and elevation position data of the near and far boundary points of the search airspace in step S2 is as follows: Calculate the azimuth angle A1 of the near-boundary scan boundary and the azimuth angle A2 of the far-boundary scan boundary: Calculate the angle α = Af - At between the target and the F radar relative to the S radar; Wherein, the position of the tracking radar is represented by point F, denoted as F radar; the position of the target radar is represented by point S, denoted as S radar; Af is the azimuth of F radar in the S coordinate system, and At is the azimuth of the jamming target indication given by S radar; Calculate the azimuth scan range θ: γ = asin(c*sinα / a); ε = asin(c*sinα / r); θ = γ - ε; Where a is the closest distance for the target search of radar F, c is the distance between radars S and F, and r is the farthest distance for the target search of radar F. Calculate the azimuth angle A1 of the near-boundary scan endpoint: β = α + γ; A1=Af-β; if A1<0, then A1=Af-β+360°; Calculate the azimuth angle A2 of the far-boundary scan endpoint: ω = α + ε; A2=Af-ω; if A2<0, then A2=Af-ω+360°; Calculate the near-boundary scan boundary pitch angle E1 and the far-boundary scan boundary pitch angle E2: If |α|=0, then: b = a + c; d = r + c; If |α|=180°, then: b=ac; d=rc; otherwise: b = a * sin(180 - β) / sinα; d = r * sin(180 - ω) / sinα; Calculate the near-boundary height h1 = b * tgEt; Where Et is the elevation of the jamming target indication given by the S radar; Calculate the far boundary height h2 = d * tgEt; Calculate the near-boundary pitch E1 = ctg(h1 / a); Calculate the far-bound pitch E2 = ctg(h2 / r); Obtain the near boundary point (A1, E1) and far boundary point (A2, E2) of the scan range; Step S3: Arrange the beam positions and perform beam coverage on the airspace connecting the near and far boundary beam positions.

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