JPH023471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of a PPI display device for displaying target distance information and azimuth information in a radar system.

[Prior art]

Figure 1 shows conventional PPI in radar systems.
FIG. 2 is a configuration diagram of a display device. In FIG. 1, 1 is a sweep display position generation section that generates a sweep display position signal, 2 is a sweep brightness control section that controls the sweep brightness, and 3 is a control section that controls the sweep display position generation section 1 and sweep brightness control section 2. 4 is a symbol display position generating section that generates a symbol display position signal; 5 is a symbol brightness control section that controls a symbol brightness signal; and 6 is the symbol display position generating section 4 and symbol brightness control. 7 is a switching control unit for switching and outputting the sweep display position signal and brightness signal and the symbol display position signal and brightness signal generated by the sweep generating unit 3 and symbol generating unit 6. 8 is a display section that displays sweeps and symbols based on the display position signal and brightness signal output from the switching control section 7, a is the azimuth data of the radar antenna, and b is a trigger that indicates the emission timing of the electron beam. The pulse, c, is a target echo signal, and d is a display data signal specifying the display position and brightness of various symbols.

Conventional PPI display devices display PPI (Plan Position)
As the name ``Indicator'' suggests, it displays the actual distance to the target that reflects the electron beam emitted from the radar antenna, or the horizontal distance projected on a horizontal plane, in a 360 degree range around the radar antenna. .

Figure 2 shows an example where there is a target with a certain altitude in the northeast direction (azimuth angle of 45 degrees). In Fig. 2, 9 is the radar antenna, 10 is the target aircraft, R is the actual distance to the target 10, Rh is the horizontal distance to the target 10, H is the altitude of the target 10,
AZ is the azimuth angle of the radar antenna 9, and EL is the elevation angle of the radar antenna 9. FIG. 3 shows an example of displaying the actual distance R to the target 10 in the situation shown in FIG. 2.

In FIG. 3, 11 is the display screen of the display unit 8;
12 is a display of the echo signal of the target 10. In addition, in the situation shown in Figure 2, goal 10
FIG. 4 shows an example of displaying the horizontal distance Rh.
In FIG. 4, 11 and 12 are the same as in FIG.

However, in the display method using the actual distance R to the target 10 as shown in FIG.
When the target 10 is almost directly above the radar antenna 9 and the actual distance is R, the display screen 1
1, the display position will be the same. Accordingly
The observer of the PPI display device can see the azimuth AZ of target 10.
Although the actual distance R was known, the altitude H of target 10 was unknown. An example of such a situation is shown in FIG. Figure 5 shows the relationship between two targets at the same actual distance and the radar antenna.
In the figure, 9, 10 and R are the same as in FIG.

Furthermore, in the display method using the horizontal distance Rh to the target 10 as shown in FIG.
Even when the target 10 has a certain altitude, the display position on the display screen 11 will still be the same as when the horizontal distance is Rh. Accordingly
The observer of the PPI display device can see the azimuth AZ of target 10.
Although the horizontal distance Rh was known, the target's altitude H was unknown. An example of such a case is shown in FIG. In FIG. 6, 9, 10 and Rh are the same as in FIG.

As described above, the PPI display device has a fundamental drawback in that the altitude information of the target 10 cannot be displayed because the display format is two-dimensional. Therefore, in conventional PPI display devices, whether in the display method using the actual distance or the display method using the horizontal distance, the elevation angle EL of the radar antenna 9 is displayed on a part of the PPI display screen to indirectly display the elevation angle EL. A format for displaying the altitude of the target 10 is well known. An example of this is shown in FIGS. 7 and 8.

In FIGS. 7 and 8, 11 is the same as in FIG. 3, and 13 is the elevation angle EL of the radar antenna 9.
These are scales and indicators that show the However, even if such a method was used, it was still difficult to directly read the altitude of target 10.

[Summary of the invention]

This invention was made with the aim of improving the drawback that conventional PPI display devices cannot display target altitude information as described above. Most of the display devices were monochrome CRTs that used phosphors, but in this invention, the display section 8 was changed to a display section that could display color.
By providing a color signal generation section that generates color signals in the sweep generation section 3 and the symbol generation section 6, a PPI display device that displays altitude information of the target 10 is provided.

[Embodiments of the invention]

Figure 9 shows the color when this invention is implemented.
This is the configuration of a PPI display device. In Figure 9,
1, 2, 3, 4, 5, 6, 7, a, b, c and d
is the same as in FIG. 1, 14 is a sweep color signal generator that generates a color signal to display the altitude information of the target 10 in color, and 15 is a symbol that generates a color signal to display the symbol in color.・Color signal generation unit, 16 is a color signal switching control unit that switches and outputs the color signals generated by the sweep color signal generation unit 14 and the symbol color signal generation unit 15, and 17 is a switching control unit 7 and color signal switching A color display section displays sweeps and symbols in color using a display position signal, a brightness signal, and a color signal output from the control section 16, and l is elevation angle data of the radar antenna.

In order to simplify the explanation, we will limit the explanation here to the case where a shadow mask type CRT having three types of phosphors, red, green, and blue, is used in the color display section 17.
An embodiment of this invention will be described. Also,
In the case of a shadow mask type CRT having three types of phosphors, red, green, and blue, any type of color display is possible by combining the light emission levels of each of the three types of phosphors. However, in order to simplify the explanation, here, the explanation will be made assuming that color display is performed using only three colors, red, green, and blue.

The relationship between the time t from emitting an electron beam from the radar antenna 9 to receiving the echo signal of the target 10 at the actual distance R is as follows, where C is the speed of light.
It is expressed by equation (1).

t=2×R/C...(1) Also, the elevation angle EL of the radar antenna 9 at this time
The relationship between the actual distance R and altitude H of target 10 is given by (2)
It is expressed by the formula.

H=R×sin(EL)...(2) From equations (1) and (2), H=C×t×sin(EL)/2...(3). In equation (3), since the speed of light C is a constant, the altitude H of the target 10 can be expressed by the elevation angle EL of the radar antenna 9 and the elapsed time t after emitting the electron beam. Here, the relationship between red, green, blue and altitude is determined as shown in FIG.
In FIG. 10, 9 and 10 are the same as in FIG. 2, Rd is red, G is green, B is blue, and EL ₁ ,
EL ₂ and EL ₃ indicate elevation angles of the radar antenna 9 with respect to the three targets 10, and H ₁ , H ₂ and H ₃ indicate boundary altitudes of the color altitude display.

The altitude H determined by equation (3) is 0≦H<
By generating a color signal in the sweep color signal generator, the altitude information is colored so that if H ₁ , the color is red; if H ₁ ≦H<H ₂ , the color is green; and if H ₂ ≦H, the color is blue. It can be expressed as FIG. 11 shows the timing of color signal generation in the three situations shown in FIG. 10. In Figure 11, b and c are the same as in Figure 1, R and H are the same as in Figure 2,
Rd, G and B are the same as in FIG.

In the above explanation, the explanation was centered on the sweep generation part, but the color display of symbol altitude information is achieved by adding display data specifying a color to the symbol display data signal d sent to the color PPI display device. By adding a color signal and generating a color signal using a symbol/color signal generator, color display can be easily performed.

In the above description, the color display was performed using three colors, red, green, and blue, but it goes without saying that the altitude can be displayed in more detail by increasing the number of display colors. In addition, although the case where a shadow mask type CRT is used as a color display section has been explained as an example, any display capable of displaying color such as a liquid crystal display (LCD) or a plasma display panel (PDP) can also be used. It goes without saying that the invention can be put into practice.

〔Effect of the invention〕

As explained above, this invention generates a color signal based on the elevation angle EL of the radar antenna 9 and the trigger pulse indicating the radiation timing of the electron beam, and displays it in color.
This has the effect of improving the drawback that the PPI display device cannot display the altitude information of the target 10.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional PPI display device, Figure 2 is a diagram showing the relationship between a radar antenna and a target, Figure 3 is a diagram showing an example of PPI display based on actual distance, and Figure 4 is a diagram showing PPI display based on horizontal distance. A diagram showing an example of the display, FIG. 5 is a diagram showing the relationship between two targets with the same actual distance and the radar antenna, FIG. 6 is a diagram showing the relationship between two targets with the same horizontal distance and the radar antenna, and FIGS. Fig. 8 is a diagram showing an example of the elevation angle display of the radar antenna, Fig. 9 is a configuration diagram of a color PPI display device according to the present invention, Fig. 10 is a diagram showing the relationship between altitude and color display, and Fig. 1
Figure 1 is a diagram showing the timing of altitude and color display. In the figure, 1 is a sweep display position generation section, 2 is a sweep brightness control section, 3 is a sweep generation section, 4 is a symbol display position generation section, 5 is a symbol brightness control section,
6 is a symbol generation section, 7 is a switching control section, 8 is a display section, 9 is a radar antenna, 10 is a target, 11 is a display screen of the display section, 12 is an echo signal of the target, 13
14 is a sweep color signal generation section, 15 is a symbol color signal generation section, 16 is a color signal switching control section, and 17 is a color display section. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

Claims (1)

[Claims] 1. In order to display target distance and azimuth information, a sweep display position generator generates a PPI sweep display position signal using a trigger pulse that indicates the azimuth angle of the radar antenna and the emission timing of the electron beam. A sweep generation section that includes a sweep brightness control section that controls a PPI sweep brightness signal using an echo signal, and a sweep color signal generation section that generates a sweep color signal based on the elevation angle of the radar antenna and the trigger pulse. and a symbol generating section that generates a color signal, a display position signal, and a brightness signal in order to display various symbols in color based on data input from a computer that controls the entire radar system, and the sweep display position generating section and a switching control section that switches between the output signal of the sweep brightness control section and the display position and brightness signals output from the symbol generation section; and a switching control section that switches between the output signal of the sweep color signal generation section and the color signal of the symbol generation section. It is characterized by comprising a color signal switching control section, and a display section that inputs signals output from the switching control section and the color signal switching control section and displays PPI sweeps and various symbols in color.
PPI display device.