阅读说明：本技术 一种雷达遮蔽盲区标定方法及装置 (Radar blind area shielding calibration method and device ) 是由 王日冬 张志� 朱宇涛 谭礼晋 余博 杨丽萍 李娜 李超 于 2020-12-25 设计创作，主要内容包括：本发明涉及一种雷达遮蔽盲区标定方法及装置,属于雷达技术领域,解决雷达遮蔽盲区的标定问题,方法包括以下步骤：基于雷达探测区域数字地图信息,建立基于规则矩形网格参考面的数字高程模型DEM；每个网格点中包括一个DEM高程；在网格参考面上,以雷达探测点所在的网格点S(i,j)为原点,以行号为i的网格为横轴,以列号为j的网格为纵轴,按平面直角坐标系八象限划分方式,将数字高程模型DEM的网格区域分割成八条网格方向线和由相邻网格方向线间隔的八个网格象限；采用射线法对八条网格方向线上的雷达盲区进行标定；采用参考面法对八个网格象限上的雷达盲区进行标定。本发明可利用多核CPU执行并行计算,实现360°雷达全方位遮蔽盲区的快速标定。(The invention relates to a method and a device for calibrating a radar blind area, which belong to the technical field of radars and solve the problem of calibrating the radar blind area, and the method comprises the following steps: establishing a digital elevation model DEM based on a regular rectangular grid reference surface based on the digital map information of the radar detection area; each grid point comprises a DEM elevation; on a grid reference surface, taking a grid point S (i, j) where a radar detection point is located as an origin, taking a grid with a row number of i as a horizontal axis, taking a grid with a column number of j as a vertical axis, and dividing a grid area of a digital elevation model DEM into eight grid direction lines and eight grid quadrants spaced by adjacent grid direction lines according to a plane rectangular coordinate system eight-quadrant division mode; calibrating radar blind areas on the eight grid direction lines by adopting a ray method; and calibrating the radar blind areas on the eight grid quadrants by adopting a reference surface method. The invention can utilize the multi-core CPU to execute parallel computation and realize the rapid calibration of the 360-degree radar omnibearing shielding blind area.)

1. A radar blind area shielding calibration method is characterized by comprising the following steps:

establishing a digital elevation model DEM based on a regular rectangular grid reference surface based on the digital map information of the radar detection area; each grid point comprises a DEM elevation;

on a grid reference surface, taking a grid point S (i, j) where a radar detection point is located as an origin, taking a grid with a row number of i as a horizontal axis, taking a grid with a column number of j as a vertical axis, and dividing a grid area of a digital elevation model DEM into eight grid direction lines and eight grid quadrants spaced by adjacent grid direction lines according to an eight-quadrant division mode of a plane rectangular coordinate system;

calibrating radar blind areas on the eight grid direction lines by adopting a ray method;

and calibrating the radar blind areas on the eight grid quadrants by adopting a reference surface method.

2. The method for calibrating a radar shadow according to claim 1, wherein the method for calibrating a radar shadow on each grid direction line comprises:

1) starting from the origin point, outwards finding a first grid point with a first DEM elevation larger than that of the origin point along a grid direction line, and drawing a first elevation ray by taking the DEM elevation values of the origin point and the first grid point as a base point; each grid point on the outward grid direction line of the first grid point corresponds to a first elevation ray elevation value;

2) starting from the first grid point, searching a second grid point with the DEM elevation larger than the elevation value of the first elevation ray along the same direction as the step 1); if the second grid point does not exist in the radar detection range, the spatial point with the elevation value below the first elevation ray on the grid direction line from the first grid point outwards is marked as a radar blind area;

3) if the second grid point exists, on a grid direction line between the first grid point and the second grid point, a space point with an elevation value below a first elevation ray is marked as a blind area of the radar;

4) then drawing a second elevation ray by taking the DEM elevation value of the origin and the second grid point as a base point; each grid point on the outward grid direction line of the second grid point corresponds to a second elevation ray elevation value;

5) starting from the second grid point, searching a third grid point with the DEM elevation larger than the elevation value of the second elevation ray along the same direction as the step 1); if the third grid point does not exist in the radar detection range, the space point with the elevation value below the second elevation ray on the grid direction line from the second grid point outwards is marked as a radar blind area;

6) if a third grid point exists, on a grid direction line between the second grid point and the third grid point, a space point with an elevation value below a second elevation ray is marked as a blind area of the radar;

and analogizing until the blind areas of all grid points on the grid direction line in the radar detection range are calibrated.

3. The method for calibrating radar shadow areas according to claim 2, wherein radar shadow areas on eight grid direction lines are calibrated simultaneously by adopting a parallel computing method.

4. The method for calibrating radar shadow area according to claim 1, wherein the method for calibrating the radar shadow area in each grid quadrant comprises the following steps:

1) determining auxiliary grid points according to grid quadrant numbers divided according to a plane rectangular coordinate system;

for the quadrants of the first grid, the fourth grid, the fifth grid and the eighth grid, starting from an origin S, acquiring outwards two grid points to be calibrated which are closest to the origin S, and are closest to the grid points to be calibrated, wherein the two grid points are positioned between the origin S and the grid points to be calibrated and have the same grid line number as auxiliary grid points t1 and t 2;

for quadrants of second, third, sixth and seventh grids, starting from an origin S, acquiring outwards two grids to be calibrated which are closest to the origin S, and taking two grids which are positioned between the origin S and the grids to be calibrated and are closest to the grids to be calibrated and have the same grid column number as auxiliary grid points t1 and t 2;

2) establishing a spatial reference plane consisting of an origin S and two auxiliary grid points t1 and t 2;

3) calculating the minimum elevation Z of the point to be calibrated

Wherein x and y are grid coordinates of grid points to be calibrated, and x₁、y₁To assist the grid coordinates of grid point t1, r₁Is the elevation of the auxiliary grid point t 1; x is the number of₂₁、y₂₁The row distance and the column distance of the auxiliary grid points t1 and t 2; z is a radical of₂₁The elevation difference for the auxiliary grid points t1, t 2; x is the number of₃₁、y₃₁A row-wise distance and a column-wise distance which are the auxiliary grid points t1 and the origin S; z is a radical of₃₁The height difference of the auxiliary grid point t1 and the origin S;

4) marking space points with the elevation smaller than the minimum elevation Z as blind areas of the radar at the grid points to be marked;

5) and sequentially moving the coordinates of the grid to be calibrated outwards, and repeating the steps 1) -4) to calibrate the blind area of the radar of the grid to be calibrated until the boundary detected by the radar.

5. The method for calibrating radar shadow area according to claim 5, wherein the radar shadow areas on eight grid quadrants are calibrated simultaneously by adopting a parallel computing method.

6. The radar blind area shielding calibration device is characterized by comprising a digital elevation model DEM, a DEM partition module, a first calculation unit, a second calculation unit,

The digital elevation model DEM is based on a regular rectangular grid reference surface; each grid point comprises a DEM elevation;

the DEM partitioning module is used for partitioning the DEM area of the digital elevation model into eight grid direction lines and eight grid quadrants separated by grid lines based on an eight-quadrant partitioning mode of a plane rectangular coordinate system by taking grid points S (i, j) where radar detection points are located as an origin, taking grids with row numbers of i as a horizontal axis and taking grids with column numbers of j as a vertical axis;

the first calculation unit is used for acquiring eight grid direction line partitions from the DEM partition module and calibrating radar blind areas on the eight grid direction lines by adopting a ray method;

and the second calculation unit is used for acquiring eight grid quadrant partitions from the DEM partition module and calibrating radar blind areas of the eight grid quadrants by adopting a reference surface method.

7. The radar blind area calibration apparatus according to claim 6, wherein the first calculation unit executes the radar blind area calibration method according to claim 2.

8. The radar shadow calibration device according to claim 7, wherein the first computing unit executes the radar shadow zones on the eight grid direction lines in parallel by using a multi-core CPU by using a multi-thread technology.

9. The radar blind area calibration apparatus according to claim 6, wherein the second calculation unit executes the radar blind area calibration method according to claim 4.

10. The radar shadow calibration device according to claim 9, wherein the second computing unit executes the radar shadow areas of eight grid quadrants in parallel by using a multi-core CPU by using a multi-thread technique.

Technical Field

The invention relates to the technical field of radars, in particular to a method and a device for calibrating a radar blind area.

Background

The radar terrain shielding dead zone is formed by the fact that radar waves are shielded by a terrain fluctuating area in the space advancing process, such as mountains, hills, forests and the like, so that a radar wave can not reach a space area within an effective action distance (threat radius). The formation of radar terrain shadowing is dependent only on the terrain and the radar transmit antenna position.

The conventional calculation of the radar shielding dead zone calculates each point one by adopting the same method, has large calculation amount and low speed, and cannot meet the requirement of quickly calibrating the 360-degree omnibearing radar shielding dead zone.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a method and an apparatus for calibrating a radar blind area, so as to solve the problem of fast calibration of a radar blind area.

The technical scheme provided by the invention is as follows:

the invention discloses a radar shielding blind area calibration method, which comprises the following steps:

establishing a digital elevation model DEM based on a regular rectangular grid reference surface based on the digital map information of the radar detection area; each grid point comprises a DEM elevation;

on a grid reference surface, taking a grid point S (i, j) where a radar detection point is located as an origin, taking a grid with a row number of i as a horizontal axis, taking a grid with a column number of j as a vertical axis, and dividing a grid area of a digital elevation model DEM into eight grid direction lines and eight grid quadrants spaced by adjacent grid direction lines according to an eight-quadrant division mode of a plane rectangular coordinate system;

calibrating radar blind areas on the eight grid direction lines by adopting a ray method;

and calibrating the radar blind areas on the eight grid quadrants by adopting a reference surface method.

Further, the radar blind area calibration method on each grid direction line comprises the following steps:

1) starting from the origin point, outwards finding a first grid point with a first DEM elevation larger than that of the origin point along a grid direction line, and drawing a first elevation ray by taking the DEM elevation values of the origin point and the first grid point as a base point; each grid point on the outward grid direction line of the first grid point corresponds to a first elevation ray elevation value;

2) starting from the first grid point, searching a second grid point with the DEM elevation larger than the elevation value of the first elevation ray along the same direction as the step 1); if the second grid point does not exist in the radar detection range, the spatial point with the elevation value below the first elevation ray on the grid direction line from the first grid point outwards is marked as a radar blind area;

3) if the second grid point exists, on a grid direction line between the first grid point and the second grid point, a space point with an elevation value below a first elevation ray is marked as a blind area of the radar;

4) then drawing a second elevation ray by taking the DEM elevation value of the origin and the second grid point as a base point; each grid point on the outward grid direction line of the second grid point corresponds to a second elevation ray elevation value;

5) starting from the second grid point, searching a third grid point with the DEM elevation larger than the elevation value of the second elevation ray along the same direction as the step 1); if the third grid point does not exist in the radar detection range, the space point with the elevation value below the second elevation ray on the grid direction line from the second grid point outwards is marked as a radar blind area;

6) if a third grid point exists, on a grid direction line between the second grid point and the third grid point, a space point with an elevation value below a second elevation ray is marked as a blind area of the radar;

and analogizing until the blind areas of all grid points on the grid direction line in the radar detection range are calibrated.

Furthermore, radar blind areas on the eight grid direction lines are calibrated simultaneously by adopting a parallel computing method.

Further, the method for calibrating the radar blind area on each grid quadrant comprises the following steps:

1) determining auxiliary grid points according to grid quadrant numbers divided according to a plane rectangular coordinate system;

for the quadrants of the first grid, the fourth grid, the fifth grid and the eighth grid, starting from an origin S, acquiring outwards two grid points to be calibrated which are closest to the origin S, and are closest to the grid points to be calibrated, wherein the two grid points are positioned between the origin S and the grid points to be calibrated and have the same grid line number as auxiliary grid points t1 and t 2;

for quadrants of second, third, sixth and seventh grids, starting from an origin S, acquiring outwards two grids to be calibrated which are closest to the origin S, and taking two grids which are positioned between the origin S and the grids to be calibrated and are closest to the grids to be calibrated and have the same grid column number as auxiliary grid points t1 and t 2;

2) establishing a spatial reference plane consisting of an origin S and two auxiliary grid points t1 and t 2;

3) calculating the minimum elevation Z of the point to be calibrated

Wherein x and y are grid coordinates of grid points to be calibrated, and x₁、y₁To assist the grid coordinates of grid point t1, r₁Is the elevation of the auxiliary grid point t 1; x is the number of₂₁、y₂₁The row distance and the column distance of the auxiliary grid points t1 and t 2; z is a radical of₂₁The elevation difference for the auxiliary grid points t1, t 2; x is the number of₃₁、y₃₁A row-wise distance and a column-wise distance which are the auxiliary grid points t1 and the origin S; z is a radical of₃₁The height difference of the auxiliary grid point t1 and the origin S;

4) marking space points with the elevation smaller than the minimum elevation Z as blind areas of the radar at the grid points to be marked;

5) and sequentially moving the coordinates of the grid to be calibrated outwards, and repeating the steps 1) -4) to calibrate the blind area of the radar of the grid to be calibrated until the boundary detected by the radar.

Furthermore, a parallel computing method is adopted to calibrate the radar blind areas on the eight grid quadrants simultaneously.

The invention also discloses a radar shielding blind area calibration device which comprises a digital elevation model DEM, a DEM partition module, a first calculation unit, a second calculation unit,

The digital elevation model DEM is based on a regular rectangular grid reference surface; each grid point comprises a DEM elevation;

the DEM partitioning module is used for partitioning the DEM area of the digital elevation model into eight grid direction lines and eight grid quadrants separated by grid lines based on an eight-quadrant partitioning mode of a plane rectangular coordinate system by taking grid points S (i, j) where radar detection points are located as an origin, taking grids with row numbers of i as a horizontal axis and taking grids with column numbers of j as a vertical axis;

the first calculation unit is used for acquiring eight grid direction line partitions from the DEM partition module and calibrating radar blind areas on the eight grid direction lines by adopting a ray method;

and the second calculation unit is used for acquiring eight grid quadrant partitions from the DEM partition module and calibrating radar blind areas of the eight grid quadrants by adopting a reference surface method.

Further, the first calculating unit executes the radar blind area calibration method of claim 2.

Furthermore, the first computing unit adopts a multithreading technology and utilizes a multi-core CPU to execute radar blind areas on eight grid direction lines in parallel.

Further, the second calculating unit executes the radar blind area calibration method of claim 4,

furthermore, the second computing unit adopts a multithreading technology and utilizes a multi-core CPU to execute radar blind areas of eight grid quadrants in parallel.

The invention can realize at least one of the following beneficial effects:

the radar blind area calibration method divides a digital elevation model into eight grid direction lines and eight grid quadrants which are respectively independent, adopts a ray method and a reference surface method to respectively and independently calibrate the radar blind area based on the characteristics of the grid direction lines and the grid quadrants, and can utilize a multi-core CPU to execute parallel calculation to realize the rapid calibration of the 360-degree radar omnibearing blind area.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

Fig. 1 is a flowchart of a method for calibrating a radar shielding blind area in the first embodiment;

fig. 2 is a schematic diagram illustrating DEM area division in the first embodiment;

fig. 3 is a schematic connection diagram of the radar blind area calibration apparatus in the second embodiment.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.

Example one

The embodiment discloses a radar blind area calibration method, as shown in fig. 1, including the following steps:

step S1, establishing a digital elevation model DEM based on a regular rectangular grid reference surface based on the digital map information of the radar detection area; each grid point comprises a DEM elevation;

specifically, the size of the regular rectangular grid of the reference surface, that is, the width of the line interval dx and the column interval dy of the grid, may be determined according to the resolution requirement for calibrating the radar shadow area, and each grid point (m, n) includes one DEM elevation information r.

Step S2, on a grid reference surface, taking a grid point S (i, j) where a radar detection point is located as an origin, taking a grid with a row number of i as a horizontal axis, taking a grid with a column number of j as a vertical axis, and dividing a grid area of a digital elevation model DEM into eight grid direction lines (first to eighth grid direction lines) according to an eight-quadrant division mode of a plane rectangular coordinate system as shown in FIG. 2; and eight grid quadrants separated by adjacent grid direction lines; (the first to eighth grid quadrants are arranged clockwise).

Step S3, calibrating the radar blind areas on the eight grid direction lines by adopting a ray method;

observing from the radar detection point to the eight grid direction lines, wherein the detection point, the point to be calibrated and a possible grid point forming a shielding relation are all on the grid direction lines, so radar blind areas on the eight grid direction lines are calibrated by adopting a ray method;

the method for calibrating the radar blind area on each grid direction line comprises the following steps:

1) starting from the origin point, outwards finding a first grid point with a first DEM elevation larger than that of the origin point along a grid direction line, and drawing a first elevation ray by taking the DEM elevation values of the origin point and the first grid point as a base point; each grid point on the outward grid direction line of the first grid point corresponds to a first elevation ray elevation value;

2) starting from the first grid point, searching a second grid point with the DEM elevation larger than the elevation value of the first elevation ray along the same direction as the step 1); if the second grid point does not exist in the radar detection range, the spatial point with the elevation value below the first elevation ray on the grid direction line from the first grid point outwards is marked as a radar blind area;

3) if the second grid point exists, on a grid direction line between the first grid point and the second grid point, a space point with an elevation value below a first elevation ray is marked as a blind area of the radar;

4) then drawing a second elevation ray by taking the DEM elevation value of the origin and the second grid point as a base point; each grid point on the outward grid direction line of the second grid point corresponds to a second elevation ray elevation value;

5) starting from the second grid point, searching a third grid point with the DEM elevation larger than the elevation value of the second elevation ray along the same direction as the step 1); if the third grid point does not exist in the radar detection range, the space point with the elevation value below the second elevation ray on the grid direction line from the second grid point outwards is marked as a radar blind area;

6) if a third grid point exists, on a grid direction line between the second grid point and the third grid point, a space point with an elevation value below a second elevation ray is marked as a blind area of the radar;

and analogizing until all points in the grid direction line in the radar detection range are calibrated.

Preferably, the eight mesh direction lines are independent of each other and have no cross-linking relationship with each other. Therefore, the radar blind areas on the eight grid direction lines can be calibrated simultaneously by adopting a parallel computing method.

After the radar blind areas of the eight grid direction lines are calibrated, the remaining radar blind areas caused by grid points which are divided by the eight grid direction lines and are positioned in eight quadrants are calibrated. Because the grid points of the quadrants are independent, the radar blind area calibration can be respectively carried out on each grid quadrant.

And step S4, calibrating the radar blind areas on the eight grid quadrants by adopting a reference surface method.

The specific method comprises the following steps:

1) determining auxiliary grid points according to the numbers of the grid quadrants;

for quadrants of one, four, five and eight grids, starting from an origin S, two grids to be calibrated which are closest to the grid to be calibrated and have the same grid line number are taken as auxiliary grid points t1(m is₁，n₁) And t2 (m)₂，n₂)；

For quadrants of grids of two, three, six and seven, the grid point to be calibrated which is closest to the origin S is obtained outwards, and two grid points which are positioned between the origin S and the grid point to be calibrated and are closest to the grid point to be calibrated and have the same grid column number are taken as auxiliary grid points t1(m is₁，n₁) And t2 (m)₂，n₂)；

2) Establishing a spatial reference plane consisting of an origin S and two auxiliary grid points t1 and t 2;

the grid coordinate of the auxiliary grid point t1 is x in the spatial reference plane₁、y₁DEM elevation of r₁(ii) a Grid coordinate of the auxiliary grid point t2 is x₂、y₂DEM elevation of r₂(ii) a Origin S grid coordinate x₃、y₃DEM elevation of r₃；

The equation for the reference plane is then:

to further obtain the minimum elevation of the point to be calibrated, the following auxiliary distances are calculated:

between the auxiliary grid points t1, t2,

line direction distance x₂₁＝x₂-x₁＝(m₂-m₁)×dx；

Column-wise distance y₂₁＝y₂-y₁＝(n₂-n₁)×dy；

Height difference z₂₁＝r₂-r₁；

Between the auxiliary grid point t1 and the origin S,

line direction distance x₃₁＝x₃-x₁＝(i-m₁)×dx；

Column-wise distance y₃₁＝y₃-y₁＝(j-n₁)×dy；

Height difference z₃₁＝r₃-r₁；

Between the auxiliary grid point t2 and the origin S,

line direction distance x₃₂＝x₃-x₂＝(i-m₂)×dx；

Column-wise distance y₃₂＝y₃-y₂＝(j-n₂)×dy；

Height difference z₃₂＝r₃-r₂。

3) Calculating the minimum elevation Z of the point to be calibrated

According toCalculating the minimum elevation of the point to be calibrated;

4) marking space points with the elevation smaller than the minimum elevation Z as blind areas of the radar at the grid points to be marked;

5) and sequentially moving the coordinates of the grid to be calibrated outwards, and repeating 1) -4) to calibrate the blind area of the radar of the grid to be calibrated until the boundary detected by the radar.

Preferably, the eight quadrants divided by the eight grid direction lines are independent of each other and have no cross-linking relationship with each other. Therefore, the radar blind areas on the eight grid direction lines can be calibrated simultaneously by adopting a parallel computing method.

Preferably, under the condition that the operation resources allow, calibrating the radar blind areas on eight grid direction lines and eight grid quadrants simultaneously; the speed of blind area calibration can be further accelerated.

In summary, the radar blind area calibration method adopted in this embodiment divides the digital elevation model into eight grid direction lines and eight grid quadrants which are independent respectively, and based on the characteristics of the grid direction lines and the grid quadrants, the radar blind area calibration is performed by using the ray method, which is fast and has small computation amount, and the shielding characteristics on the grid direction lines are determined only by a single grid point; and dividing the rest grids into eight mutually independent quadrants by using the pre-defined grid direction lines, and independently calibrating the radar shielding blind area by adopting a reference surface method. The method can fully utilize the advantage of parallel computation executed by the multi-core CPU, and can adopt the parallel computation for eight grid direction lines and/or eight grid quadrants so as to realize the rapid calibration of the 360-degree radar omnibearing shielding blind area.

Example two

The embodiment discloses a radar blind area calibration device, which comprises a digital elevation model DEM, a DEM partitioning module, a first calculation unit, a second calculation unit,

The digital elevation model DEM is based on a regular rectangular grid reference surface; each grid point comprises a DEM elevation;

the DEM partitioning module is used for partitioning the DEM area of the digital elevation model into eight grid direction lines and eight grid quadrants separated by grid lines based on an eight-quadrant partitioning mode of a plane rectangular coordinate system by taking grid points S (i, j) where radar detection points are located as an origin, taking grids with row numbers of i as a horizontal axis and taking grids with column numbers of j as a vertical axis;

the first calculation unit is used for acquiring eight grid direction line partitions from the DEM partition module and calibrating radar blind areas on the eight grid direction lines by adopting a ray method;

and the second calculation unit is used for acquiring eight grid quadrant partitions from the DEM partition module and calibrating radar blind areas of the eight grid quadrants by adopting a reference surface method.

More specifically, the first computing unit executes the method for calibrating the radar blind areas on the eight grid direction lines in the first embodiment.

More preferably, the first computing unit adopts a multithreading technology, and executes the radar blind areas on the eight grid direction lines in parallel by using a multi-core CPU.

More specifically, the second computing unit executes the method for calibrating the radar blind areas of the eight grid quadrants in the first embodiment.

More preferably, the second computing unit adopts a multithreading technology, and executes the radar blind areas of eight grid quadrants in parallel by using a multi-core CPU.

The specific details and technical effects in this embodiment are similar to those in the embodiment, and thus are not described herein again.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.