JPH045767A - Method for preparing radar covering area figure - Google Patents

Abstract

PURPOSE:To reduce the number of points of intersection and to improve the preparing efficiency of a radar covering area figure by adjusting the count of the points of intersection according to a cross angle of a scanning line and a mesh. CONSTITUTION:Case dividing is executed into a pattern A and a pattern B at every 45 deg. according to the angle of the altitude mesh data of a map and a scanning line (step 1), when the point of intersection is the pattern A, the coordinates of only the point of intersection with the longitudinal line of a mesh are found, when the point of intersection is the pattern B, the coordinates of only the point of intersection with the lateral line of the mesh are found (step 2), when the coordinates of the point of intersection are found, the altitude data of the point of intersection are calculated and a shielding angle with an origin is found based on the calculated altitude data (step 3) and a radar covering area figure is prepared from the found shielding angle (step 4). Thus, the number of the operated points of intersection can be reduced within a range that effects are not given to a function and the preparing efficiency of the radar covering area figure can be improved.

Description

[Detailed Description of the Invention] [Summary] Regarding the method of creating a radar coverage map, the purpose is to improve the efficiency of creating a radar coverage map, and to improve the efficiency of creating a radar coverage map.
Cases are divided into A pattern and B pattern for each degree. If it is an intersection or pattern A, find the coordinates of only the intersection with the vertical line of the mesh, and if it is an intersection or pattern B, find only the coordinates of the intersection with the horizontal line of the mesh. After finding the coordinates of the intersection, calculate the elevation data of the intersection, find the occlusion angle with the origin based on the calculated elevation data, and create a radar coverage map from the obtained occlusion angle. Configure.

[Industrial application field] The present invention relates to a method for creating a radar coverage map.

Visibility map/radar coverage map (hereinafter simply referred to as radar coverage map)
When creating a radar, find the coordinates of the intersection between the mesh and the scanning line, calculate the elevation, find the occlusion angle, and use this occlusion angle to create a coverage map (color-coded areas that are visible and invisible to the radar). It is designed to be created. Generally, there are tens of thousands of intersections between map meshes and scanning lines, which takes a lot of calculation time and requires a reduction in response time.

Therefore, it is necessary to shorten the time from when calculation conditions are input using the input device until the radar coverage map is displayed.

[Prior Art] FIG. 6 is a diagram showing how scanning lines and meshes intersect. In the figure, Ω is the scanning line.

The intersection with mesh is indicated by . The dimensions of the mesh are, for example, about 100 m both in length and width.

All mesh coordinate data is stored in advance in the storage device. Further, the scanning line p is also scanned by a predetermined angle from the origin, for example, in steps of 1°. The conventional method calculates the coordinates of all the intersection points determined in this way,
A radar coverage map is created by calculating the shielding angle from the origin (not shown) and calculating whether or not the intersection can be seen through.

FIG. 7 is an explanatory diagram of a method of calculating the shielding angle. In the figure, L is the horizontal distance from the origin O to the intersection K, and H is the altitude. Here, if the angle from the origin 0 to the intersection K is θ, then tan θ−H/L holds true. Since L and H can be determined by calculation, the shielding angle θ can be determined from H/L by back calculation. Once the shielding angle is determined, it can be determined whether the point can be seen from the origin 0, and a radar coverage map can be created.

FIG. 8 is a diagram showing how to see through. From origin O to terrain Q
looking at * shown on topography Q is an intersection point. At the shielding angle θ1, it is possible to see through only between 0 and P1 and between P2 and P3. By making the shielding angle larger than 02 and 01 at position P3, it is possible to see through P4 and beyond. Also, among the intersections shown on the terrain Q, P1 to P
Since the occlusion angle of the intersection point 2 is clearly smaller than 01, it cannot be seen through.

[Problems to be Solved by the Invention] In the conventional method, the coordinates of all the intersection points where one scanning line intersects with the mesh are determined, and the shielding angle of the intersection points is determined. Next, the scanning line is changed by 1° again, the intersection with the mesh is found, and the same operation is repeated.

In this way, in the conventional method, the occlusion angle is determined by considering all the intersections between the elevation mesh data and the angular scan line, and although the results are good, the calculation takes a considerable amount of time. The problem was that it was inefficient.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for creating a radar coverage map with improved creation efficiency.

[Means to solve the problem] FIG. 1 is a flowchart showing the principle of the method of the present invention.

The present invention is based on the angle between the elevation mesh data of the map and the scanning line.
Separate the cases into A pattern and B pattern for each degree (step 1). If the intersection is the A pattern, find the coordinates of only the intersection with the vertical line of the mesh, and if the intersection is the B pattern, find the coordinates of the mesh horizontal line. (Step 2) Find the coordinates of only the intersection with
Step 3) Create a radar coverage map from the obtained occlusion angle (Step 4)
).

[Adjust the count of intersection points depending on the angle at which the active scanning line intersects with the mesh. As a result, the number of intersection points is reduced, so that the efficiency of creating a radar coverage map can be improved.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is an explanatory diagram of case classification of intersection patterns according to the present invention. scan line at 45° to the horizontal; &1. ,
Consider Q2. The area in the range of ±45° left and right with respect to this scanning line Ω11g2 is the A pattern area, 90° above and below.
The area within the range of is defined as pattern B. In the A pattern area, the scanning line intersects with the mesh as shown in FIG. 3(a), and in the B pattern area, the scanning line intersects with the mesh as shown in FIG. 3(b). As is clear from comparing (a) and (b), in the case of pattern A, among the intersections a-e between the scanning line and the mesh, a, c, d, and e intersect with the vertical line of the mesh. In comparison, in the case of B pattern, among the intersections a-e of the scanning line and the mesh, a, b, d
, e intersects the horizontal line of the mesh.

Based on the above characteristics, in the A pattern area, only the intersections between the scanning line and the mesh are considered as the vertical lines of the mesh, and in the B pattern area, only the intersections with the horizontal lines of the mesh are considered.

As shown in (a) and (b), some intersections may be ignored, or the number of such intersections is small, so it can be considered that there is no substantial effect. The present invention aims to reduce the number of intersections and speed up processing by appropriately thinning out the number of intersections between scanning lines and meshes in consideration of these points.

FIG. 4 is a diagram showing an example of a system configuration for implementing the method of the present invention. In the figure, 1 is an input device for inputting various information, commands, etc., and 1a is a mouse and keyboard included in the human-powered device.

2 is a display device that displays various information; 3 is a central processing unit that calculates the visibility rate according to the information input from the input device 1 and performs various processing; 4 is map data (elevation data,
This is a file (storage device) in which mesh data, etc.) is stored.

The central processing unit 3 includes a visibility map/radar coverage map condition specifying unit 3
a. Map elevation mesh data input section 3b.

It is composed of a visibility map/radar coverage map calculation section 3C and a visibility map/radar coverage map display section 3d. These visibility map/radar coverage map condition specifying section 3a, map elevation mesh data input section 3b, visibility map/radar coverage map calculation section 3C, and visibility map/radar coverage map display section 3d can be created using software, for example. . The operation of the system configured as described above will be explained as follows.

In the example below, the altitude mesh data of the map is 100m.
The mesh data is used to calculate a coverage map for a range of 15 km from the origin.

First, when the human-powered device 1 specifies the conditions for calculation such as the coordinate origin and the distance of the scanning line, the visibility map/radar coverage map condition specifying unit 3a transmits the input conditions to the map elevation mesh data input unit 3b. . The map elevation mesh data input section 3b reads the elevation mesh data of the map including the specified range from among the information stored in the storage device 4, and sends it to the visibility map/radar coverage map calculation section 3C.

The field of view map/radar coverage map calculation unit 3C performs a total of 360 or less calculations for each 1° of the angle θ between the scanning line and the mesh from 0° to 360°. First, the intersection between the relevant scanning line and the 100m mesh is found. The range of the intersection is up to 15 km from the origin. This intersection point is determined separately for A pattern and B pattern every 45 degrees as explained in FIGS. 2 and 3. Then, if the scanning line is within the range shown in FIG. 2, it is determined whether pattern A or pattern B is to be used. When using pattern A, the coordinates of the intersection points are as shown in Figure 3 (
As shown in a), the coordinates of the intersection can be found using tan. For example, the coordinates of the intersection e in the case of FIG. 3(a) can be expressed as y=400tanθ. When using pattern B,
The coordinates of the intersection point are as shown in FIG. 3(b), and the coordinates of the intersection point e are: x=400/lanθ y-4o.

It can be expressed as

Once the coordinates of the intersection points have been determined for all the intersection points (in the case of A pattern, only the intersections with the mesh vertical line, and in the case of B pattern, only the intersections with the mesh horizontal line), calculate the visibility map/radar coverage map. The section 3c calculates the altitude of each intersection point based on the altitude data of the mesh intersection point. Once the altitude has been calculated, the shielding angle with respect to the origin is determined as shown in Figure 7. The occlusion angle data obtained in this manner is sent to the visibility map/radar coverage map display section 3d. The visibility map/radar coverage map display unit 3d determines whether each intersection is visible or invisible based on the received shielding angle of each intersection. For example, if the corresponding occlusion angle is not smaller than that of the previous scan line, it will be visible, and if it is larger, it will be invisible (see FIG. 8). Each intersection obtained in this way and its visibility/
By connecting invisible points with line segments, a radar coverage map as shown in FIG. 5 can be obtained. The white portion in FIG. 5 is the visible area.

[Effects of the Invention] As described above in detail, according to the present invention, the pattern of the intersection of the mesh and the scanning line is divided into A pattern and B pattern at every 45°, and in each pattern, the mesh By calculating the occlusion angle by considering only the intersections with lines in a specific direction, the number of intersections to be calculated can be reduced without affecting the functionality, increasing the efficiency of creating radar coverage maps. It can be improved.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing the principle of the method of the present invention, Fig. 2 is an explanatory diagram of case classification of the intersection pattern according to the invention, Fig. 3 is a diagram showing an example of the intersection pattern, and Fig. 4 is the implementation of the method of the invention. Figure 5 is a diagram showing an example of creating a radar coverage map, Figure 6 is a diagram showing the intersection of the scanning line and the mesh, and Figure 7 is the calculation of the shielding angle. An explanatory diagram of the method, FIG. 8 is a diagram showing the situation of through vision. In Fig. 4, 1 is an input device, 1a is a mouse/keyboard, 2 is a display device, 3 is a central processing unit, 3a is a visibility map/radar coverage map condition specification section, 3b is a map elevation mesh data input section, and 3c is a Visibility map/radar coverage map calculation section, 3d is visibility map/radar coverage map display section.

Claims (1)

[Claims] Depending on the angle between the elevation mesh data of the map and the scanning line,
Divide the cases into A pattern and B pattern every 5 degrees (step 1). If the intersection is in A pattern, find the coordinates of only the intersection with the vertical line of the mesh, and if the intersection is in B pattern, find the coordinates of the mesh. Find the coordinates of only the point of intersection with the horizontal line (step 2). Once the coordinates of the point of intersection are found, calculate the elevation data of that point of intersection, and find the occlusion angle with the origin based on the calculated elevation data (
Step 3) Create a radar coverage map from the obtained occlusion angle (Step 4)
) A method for creating a radar coverage map.