Radar plot multi-cycle backtracking clutter suppression method based on two-dimensional velocity grid

Abstract

The present application relates to a radar plot multi-period backtracking clutter suppression method based on a two-dimensional velocity grid, and mainly solves the problems of automatic track acquisition calculation timeout caused by plot saturation in dense clutter environment, more false tracks generated by automatic track acquisition, poor user experience of target automatic track acquisition, and great difficulty in target tracking maintenance in clutter, etc. After receiving plots of N antenna scanning periods, the present application establishes a velocity grid, establishes an associated wave door about the velocity channel through backtracking, and finally outputs the plots determined as targets to automatic track acquisition and target tracking through M / N decision.

Description

Technical Field

[0001] This invention belongs to the field of radar target tracking technology, and particularly relates to the field of automatic radar target acquisition and tracking in cluttered environments. Background Technology

[0002] In the field of target tracking using two-coordinate mechanically scanned radar, target discovery and acquisition have traditionally relied heavily on manual methods. This requires operators to maintain a high level of concentration and constant monitoring during their shifts, resulting in significant workload pressure. While automatic acquisition can reduce the operator's burden in discovering, acquiring, and maintaining targets, issues arise in dense clutter environments. These include track saturation leading to timeouts in automatic track acquisition calculations, the generation of numerous false tracks, a poor user experience in automatic target acquisition, and increased difficulty in target tracking and maintenance within cluttered environments. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention proposes a multi-cycle backtracking clutter suppression method for radar tracks based on a two-dimensional velocity grid. After receiving tracks from N antenna scanning cycles, a velocity grid is established. A correlation gate for the velocity channel is then established through backtracking. Finally, after an M / N decision, tracks identified as targets are output to the automatic track acquisition and target tracking systems. This method effectively filters out false clutter tracks when there are too many input tracks to the tracker, significantly improving automatic target acquisition and tracking capabilities.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] The data is received and stored sequentially according to the antenna scanning cycle.

[0006] Set the length of the decision window. When the number of antenna scan cycles for the received trace is less than the window length, all traces are considered clutter and no trace is output.

[0007] A two-dimensional velocity grid is established with the radial velocity and azimuth velocity both being 0 as the center. Each grid in the velocity grid represents a pre-defined target motion model.

[0008] Using each point as the center, the velocity range represented by the velocity grid is traced back in each antenna scanning cycle to obtain the preset target distance range and azimuth range;

[0009] Generate associated gates based on the preset distance and orientation range of the target;

[0010] Count the number of times each velocity grid of each point contains a point in the associated gate corresponding to each antenna scanning period; output the points whose number of times the velocity grid contains a point satisfies the condition.

[0011] Compared with traditional technologies, the beneficial effects of this invention are as follows:

[0012] This invention addresses the problems of timeouts in automatic track acquisition and the generation of numerous false tracks due to track saturation in dense clutter environments. It establishes a velocity grid, establishes a correlation gate for the velocity channel through backtracking, and finally outputs tracks that meet the discrimination criteria to automatic track acquisition and target tracking, effectively filtering out false clutter tracks and improving the automatic target acquisition and tracking capabilities. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the processing flow of the present invention. Detailed Implementation

[0014] The schematic diagram of the processing flow of the radar spot multi-period backtracking clutter suppression method based on two-dimensional velocity grid of this invention is shown below. Figure 1 As shown, the preferred embodiment includes the following steps:

[0015] The data is received and stored sequentially according to the antenna scanning cycle, and the set {(r ki θ ki )} i＝1，2，... Let r represent the trace generated during the k-th antenna scan cycle. ki θ represents the distance between the points. ki Indicates the location of the dot;

[0016] The length of the decision window is set to N. When the number of antenna scan cycles of the received point is less than the window length N, all points are considered to be clutter and no points are output.

[0017] A two-dimensional velocity grid is established with the radial velocity and azimuth velocity both being 0 as the center. Each grid in the velocity grid represents a pre-defined target motion model.

[0018] Using each point as the center, the velocity range represented by the velocity grid is traced back in each antenna scanning cycle to obtain the preset target distance range and azimuth range;

[0019] Generate associated gates based on the preset distance and orientation range of the target;

[0020] Count the number of times each velocity grid of each point contains a point in the associated gate corresponding to each antenna scanning period; output the points whose number of times the velocity grid contains a point satisfies the condition.

[0021] Furthermore, the velocity grid contains P+1 grids in the radial direction and Q+1 grids in the azimuth direction, with each grid having a radial velocity width of ΔV. r The azimuth velocity width is ΔV θ ; Velocity grid G pqThis represents the radial direction from the p-th azimuth to the q-th grid, where -P / 2 ≤ p ≤ P / 2, -Q / 2 ≤ q ≤ Q / 2; the velocity grid G pq The radial velocity ranges from [(p-1 / 2)ΔV] to [(p-1 / 2)ΔV]. r (p+1 / 2)ΔV r The azimuth velocity ranges from [(q-1 / 2)ΔV] to [(q-1 / 2)ΔV]. θ (q+1 / 2)ΔV θ ];

[0022] Furthermore, with each point trace (r) ki θ ki Centered on the velocity grid G pq The velocity range is represented by the backtracking during the h-th antenna scan cycle, where kN < h < k, to obtain the range of distance to the preset target as an interval:

[0023] [ rk i+(p-1 / 2)ΔV r (kh)T,r ki +(p+1 / 2)ΔV r (kh)T];

[0024] The directional range is an interval:

[0025] [θ ki +(q-1 / 2)ΔV θ (kh)T,θ ki +(q+1 / 2)ΔV θ (kh)T];

[0026] Where T is the antenna scanning period;

[0027] Furthermore, considering the impact of radar detection errors, in the h-th antenna scanning cycle, the range and azimuth range intervals of the preset target are doubled to establish a correlation gate. The range of the correlation gate is the interval:

[0028] [r ki +(p-1)ΔV r (kh)T,r ki +(p+1)ΔV r (kh)T];

[0029] The directional range is an interval:

[0030] [θ ki +(q-1)ΔV θ (kh)T,θ ki +(q+1)ΔV θ (kh)T];

[0031] For the dot (r) hi θ hi )if:

[0032] r ki +(p-1)ΔV r (kh)T≤r hi ≤r ki +(p+1)ΔV r (kh)T;

[0033] θ ki +(q-1)ΔV θ (kh)T≤θ hi ≤θ ki +(q+1)ΔV θ (kh)T;

[0034] Then it is considered that the dot trace (r) hi θ hi ) located at the point (r ki θ ki The velocity grid G) pq In the associated gate of the h-th antenna scanning cycle.

[0035] Furthermore, the points (r) are counted separately. ki θ ki The velocity grids G of each ) pq The number of times the associated gate contains a dot pattern in the N-1th antenna scan period from k-1 to k-N+1 is S. pq .

[0036] Furthermore, if there is at least one S pq If the value is greater than the decision threshold M-1, then the point (r) is considered to be... ki θ ki If the target is r, output the point; otherwise, consider the point (r) as the target. ki θ ki () is noise, and the point will not be output.

Claims

1. A radar spot clutter suppression method based on two-dimensional velocity grids and multiple cycles of backtracking, characterized in that: The system receives and stores the points in the order of the antenna scan cycles; it sets the length of the decision window, and when the number of antenna scan cycles of the received points is less than the window length, all points are considered clutter and no points are output; it establishes a two-dimensional velocity grid with the radial velocity and azimuth velocity both being 0 as the center, and each grid in the velocity grid represents a preset target motion model. Using each point as the center, backtracking is performed in each antenna scanning cycle according to the velocity range represented by the velocity grid to obtain the preset target distance range and azimuth range; a correlation gate is generated according to the preset target distance range and azimuth range; the number of times each velocity grid of each point contains the point in the correlation gate corresponding to each antenna scanning cycle is counted; and the points whose number of times the velocity grid contains the point satisfy the condition are output.

2. The radar spot multi-cycle backtracking clutter suppression method based on a two-dimensional velocity grid according to claim 1, characterized in that: The velocity grid has P+1 grids in the radial direction and Q+1 grids in the azimuth direction, with each grid having a radial velocity width of ΔV. r The azimuth velocity width is ΔV θ ; Velocity grid G pq This represents the radial direction from the p-th azimuth to the q-th grid, where -P / 2 ≤ p ≤ P / 2, -Q / 2 ≤ q ≤ Q / 2; the velocity grid G pq The radial velocity ranges from [(p-1 / 2)ΔV] to [(p-1 / 2)ΔV]. r (p+1 / 2)ΔV r The azimuth velocity ranges from [(q-1 / 2)ΔV] to [(q-1 / 2)ΔV]. θ (q+1 / 2)ΔV θ ].

3. The radar spot multi-cycle backtracking clutter suppression method based on a two-dimensional velocity grid according to claim 2, characterized in that: With each point trace (r) ki θ ki Centered on the velocity grid G pq The velocity range is represented by the backtracking during the h-th antenna scan cycle, where kN < h < k, to obtain the range of distances to the preset target as an interval: [r ki +(p-1 / 2)ΔV r (k-h)T,r ki +(p+1 / 2)ΔV r (k-h)T]; The directional range is an interval: [i ki +(q-1 / 2)ΔV θ (kh)T,θ ki +(q+1 / 2)ΔV θ (kh)T] Where T is the antenna scanning period.

4. The radar spot multi-cycle backtracking clutter suppression method based on a two-dimensional velocity grid according to claim 3, characterized in that: To mitigate the impact of radar detection errors, during the h-th antenna scanning cycle, a correlation gate is established by doubling the range and azimuth ranges of the preset target. The range of the correlation gate is the interval: [r ki +(p-1)ΔV r (k-h)T,r ki +(p+1)ΔV r (k-h)T]; The directional range is an interval: [i ki +(q-1)ΔV θ (kh)T,θ ki +(q+1)ΔV θ (kh)T]; For the dot (r) hi θ hi ),if: r ki +(p-1)ΔV r (k-h)T≤r hi ≤r ki +(p+1)ΔV r (k-h)T; i ki +(q-1)ΔV θ (kh)T≤θ hi ≤θ ki +(q+1)ΔV θ (kh)T; Then it is considered that the dot trace (r) hi θ hi ) located at the point (r ki θ ki The velocity grid G) pq In the associated gate of the h-th antenna scanning cycle.

5. The radar spot multi-cycle backtracking clutter suppression method based on a two-dimensional velocity grid according to claim 3, characterized in that: Count the points (r) separately ki θ ki The velocity grids G of each ) pq The number of times the associated gate contains a dot pattern in the N-1th antenna scan period from k-1 to k-N+1 is S. pq .

6. The radar spot multi-cycle backtracking clutter suppression method based on a two-dimensional velocity grid according to claim 5, characterized in that: If there is at least one S pq If the value is greater than the decision threshold M-1, then the point (r) is considered to be... ki θ ki If the target is r, output the point; otherwise, consider the point (r) as the target. ki θ ki () is noise, and the point will not be output.

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