JP2008039558A - Radar system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately obtain the position of a target even if an own ship travels. <P>SOLUTION: A radar system 10 comprises: a center-of-gravity calculation section 26 for calculating a center-of-gravity G in radar images E; and a selection symbol moving section 28 for moving a selection signal to the intersection point between a straight line for connecting the center-of-gravity G and an own ship position, and the border line of the radar images E for superposition on a display 34 for display. Even if the own ship S moves, the position of the target T is obtained accurately. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radar apparatus having a display capable of displaying a selection symbol superimposed on a radar image.

  A radar apparatus that identifies a target existing around the ship by a radar and displays the radar image on a display device may display various marks based on the identified target (Patent Document 1). These various marks are used, for example, when marking a point where many fish are caught in a fishing ground.

JP, 2001-281331, A paragraph [0026]

  However, in a general radar apparatus, since the signal transmitted from the antenna of the ship is a pulse signal, the position of the target and the center of the radar image are shifted.

  For example, as shown in FIG. 5A, the contour of the radar image E obtained from the reflected signal that is transmitted from the ship S and reflected from the target T and returned is substantially elliptical. Since the target T cannot be clearly captured in the actual radar image, the radar operator of the ship S usually hits the mark M as a selection symbol in the center of the ellipse with respect to the radar image E. Are often displayed in a superimposed manner. Then, if the length in the distance direction of the radar image E is L, the actual target T and the mark M will be shifted by a distance L / 2. Thereafter, when the ship S moves as shown in FIG. 5B, the radar image of the target T becomes the radar image E ′. In this case, the distance between the mark M and the center C of the radar image E ′ is L. 5A and 5B are displayed in a relative motion mode in which the position of the ship S is fixed at the center position.

  Usually, the transmission pulse width of the pulse radar used in the radar apparatus is 0.08 to 1.2 μs. For example, when the transmission pulse width is 0.6 μs, the distance resolution of the reflected signal with respect to this is about 90 m. . This distance resolution is substantially equal to the length L of the ellipse minor axis (distance direction) in the radar image E shown in FIG. 5A. Therefore, when the transmission pulse width is 0.6 μs, the center C of the radar image E ′ and the mark M in FIG. 5B are shifted by a distance L, that is, about 90 m, and the radar operator accurately captures the target T. There was a problem that it was difficult.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a radar device that can accurately grasp the position of a target even when the ship moves. To do.

  The radar apparatus according to the present invention, in a radar apparatus having a display capable of displaying a selection symbol superimposed on a radar image, a center-of-gravity calculating means for calculating the center of gravity of the radar image, a straight line connecting the center of gravity and the ship position, Selection symbol moving means for moving the selection symbol to an intersection with the contour line of the radar image and superimposing it on the display is provided.

  According to the present invention, the ship's ship moves by calculating the center of gravity of the radar image specified by the selection symbol and moving the selection symbol to the intersection of the straight line connecting the center of gravity and the position of the ship and the contour line of the radar image. Even in this case, the position of the target can be accurately grasped.

  Another radar apparatus according to the present invention is a radar apparatus having a display capable of displaying a selection symbol superimposed on a radar image, a reading means for reading out a predetermined range including a radar image on which the selection symbol is superimposed, A selection symbol moving means for moving the selection symbol to a position closest to the ship position on the contour line of the radar image within the range and displaying the selection symbol superimposed on the display is provided.

  According to the present invention, a predetermined range including a radar image on which a selection symbol is superimposed is read, and the selection symbol is moved to a position closest to the ship position on the contour line of the radar image within the predetermined range, Even if the ship moves, the position of the target can be accurately grasped.

  According to the present invention, the ship's ship moves by calculating the center of gravity of the radar image specified by the selection symbol and moving the selection symbol to the intersection of the straight line connecting the center of gravity and the position of the ship and the contour line of the radar image. Even in this case, the position of the target can be accurately grasped. Also, the ship moves by reading a predetermined range including the radar image on which the selection symbol is superimposed and moving the selection symbol to a position closest to the ship position on the contour line of the radar image within the predetermined range. Even in this case, the position of the target can be accurately grasped.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram of a radar apparatus 10 according to an embodiment of the present invention. The radar apparatus 10 according to this embodiment basically rotates in the horizontal direction in order to transmit and receive a pulse wave in the 360 degree direction, and has an antenna 12 installed in a place with a good view like a ship mast, An antenna control unit 14 including a transceiver that controls the rotation of the antenna 12 and transmits / receives a pulse signal, an A / D conversion unit 16 that converts a signal received by the antenna control unit 14 into a digital signal, and an A / D conversion unit A coordinate conversion unit 18 that converts the digital signal in polar coordinate format converted in 16 into a digital signal in rectangular coordinate format, a radar image memory 20 in which the signal converted in the coordinate conversion unit 18 is written as a radar image, and a radar operator Control of the pulse signal transmission / reception in the operation unit 22 including the keyboard, mouse, trackball, etc. The CPU 24 controls the writing of the digital signal from the / D conversion unit 16 to the radar video memory 20 via the coordinate conversion unit 18 and the operation unit 22 to control the variable distance scale, the bow line, A graphic memory 30 in which graphic data such as a mark and a cursor is written, and a display control unit 32 that synthesizes the radar video written in the radar video memory 20 and the graphic data written in the graphic memory 30 and outputs them as a video signal. And a display 34 for displaying a video signal from the display control unit 32.

  The radar apparatus 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation thereof will be described with reference to FIGS. 2A to 2D. 2A to 2D are diagrams for explaining the movement of the selection symbol with respect to the display on the display 34 on which the own ship S and the radar image E are displayed.

  In the radar apparatus 10, a pulse signal is generated by the antenna control unit 14 in accordance with a control signal from the CPU 24, and then a radio signal modulated by this pulse signal is transmitted from the antenna 12, reflected from the target T, and returned. The reflected signal is received by the antenna control unit 14. The received signal from the antenna control unit 14 is converted into a digital signal by the A / D conversion unit 16, converted from polar coordinates to orthogonal coordinates by the coordinate conversion unit 18, and written in the radar video memory 20. Then, it is displayed on the display 34. A radar operator of the ship S performs an operation of placing a mark M as a selection symbol at the center of the radar image E by the operation unit 22, and under the control of the CPU 24, the mark M is displayed as graphic data from the graphic memory 30. 32 and displayed on the display 34 together with the radar image E (FIG. 2A).

  The CPU 24 reads a certain area A based on the mark M from the radar image memory 20 among the radar images written in the radar image memory 20 (FIG. 2B). 2B to 2D are enlarged views of the region A of the radar image in FIG. 2A. This area A can be a square of 32 dots centered on the mark M, for example. In a medium-sized and large-sized radar displaying a general PPI (Plan Position Indicator scope), the display radius is 348 to 456 dots. For example, when the range is 3 nm (Nautical Mile), one side of one dot is displayed. The length is about 16m. Therefore, the length of one side of the 32-dot square in the region A is 512 m.

  Next, the center-of-gravity calculation unit 26 of the CPU 24 calculates the center of gravity G of the area of the radar image E in the area A (note that the center of gravity G is not actually displayed on the radar image E). The center of gravity G can be obtained, for example, by weighting and calculating the position of each pixel in the area of the radar image E (FIG. 2C).

  The selection symbol moving unit 28 of the CPU 24 obtains the intersection of the line connecting the center of gravity G and the ship S and the contour line of the radar image E as the leading edge, and the position information of the leading edge is obtained via the graphic memory 30. It outputs to the display control part 32, moves the mark M to a front edge, and displays it on the indicator 34 (FIG. 2D). Here, the leading edge means the position of the point after the mark M is moved.

  Further, as shown in FIG. 3, a general radar image E is displayed in gradation, and a value obtained by adding a certain level Δ to the level of noise included in the radar image is set as a threshold value. It can be obtained as the contour line of the image E. In the radar displayed with 16 gradations, for example, when the noise level is 3, the contour line can be obtained by setting a level 5 obtained by adding a certain level Δ, for example, 2 to the noise level.

  Further, as the area A shown in FIG. 2B, a guard zone as shown in FIG. 4A can be used. After the radar operator of own ship S hits the mark M at the center of the radar image E, the guard zone Z may be selected as a selection symbol so as to surround the radar image E, and this surrounded region may be set as the region A. . After calculating the center of gravity G from the radar image E in the area A surrounded by the guard zone Z by the center of gravity calculation unit 26 as described above (see FIG. 2C), the line connecting the center of gravity G and the ship S and the radar image E The intersection of the contour lines of the region is obtained as the leading edge, the position information of the leading edge is output to the display control unit 32 via the graphic memory 30, and the mark M is moved to the leading edge and displayed on the display 34 ( FIG. 4B).

  Here, the guard zone generally means that the radar operator visually observes the relative distance and direction between the ship S and the target T from the radar image E displayed around the ship S, and the danger of collision. There are four points on the screen as vertices so that the relative distance and direction can be easily determined on the screen, and they are surrounded by line segments connecting these four vertices. An area of a quadrangle or a ring piece (a shape obtained by cutting a ring with two radial lines).

  Further, the leading edge can be obtained without using the center of gravity G. That is, the point on the contour line that minimizes the distance between the point on the contour line of the region of the radar image E and the ship S can be used as the leading edge (FIG. 4C). In this case, after obtaining the radar image E, the mark M is spotted (FIG. 2A), and the distance between the point on the contour line of the area of the radar image E and the ship S is minimized by the selection symbol moving unit 28. This point is obtained as the leading edge, and the position information of the leading edge is output to the display control unit 32 via the graphic memory 30, and the mark M is moved to the leading edge and displayed on the display 34 (FIG. 4C).

  As described above, the radar apparatus 10 according to this embodiment identifies the radar image E with the mark M that is a selection symbol, calculates the center of gravity G of the radar image E with the center of gravity calculation unit 26, and determines the center of gravity G and the ship itself. This is a case where the ship S moves by moving the selection symbol to the front edge and displaying it on the display 34 with the intersection of the straight line connecting the positions of S and the contour line of the radar image E as the front edge. However, the position of the target T can be accurately grasped.

  Further, the CPU 24 reads out a predetermined range including the radar image on which the selection symbol is superimposed and displayed from the radar image memory 20, and sets the position closest to the position of the ship S on the contour line of the radar image E in the predetermined range. As the edge is obtained by the selection symbol moving unit 28, the selection symbol is moved to the leading edge and superimposed on the display 34, so that the position of the target T can be accurately determined even when the ship S moves. I can grasp it.

  It should be noted that the present invention is used in any of the display modes of the relative motion mode in which the position of the ship is fixed and displayed at the center position and the true motion mode in which the position of the ship is moved and displayed according to the motion of the ship. be able to.

  In addition, the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

1 is a block diagram of a radar apparatus according to an embodiment of the present invention. 2A to 2D are diagrams for explaining the movement of the selection symbol with respect to the radar image. It is a figure which shows the gradation display of the general radar image | video. 4A to 4C are explanatory diagrams of modifications of the radar apparatus according to the embodiment of the present invention. 5A and 5B are diagrams for explaining the hit points of the mark M in the conventional radar apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Radar apparatus 12 ... Antenna 14 ... Antenna control part 16 ... A / D conversion part 18 ... Coordinate conversion part 20 ... Radar image memory 22 ... Operation part 24 ... CPU (control part)
DESCRIPTION OF SYMBOLS 26 ... Gravity center calculation part 28 ... Selection symbol moving part 30 ... Memory for graphics 32 ... Display control part 34 ... Display

Claims (2)

In a radar apparatus having a display capable of displaying a selection symbol superimposed on a radar image,
Centroid calculating means for calculating the centroid of the radar image;
A radar comprising: selection symbol moving means for moving the selection symbol to an intersection of a straight line connecting the center of gravity and the ship position and a contour line of the radar image and superimposing the selection symbol on the display apparatus. In a radar apparatus having a display capable of displaying a selection symbol superimposed on a radar image,
Reading means for reading a predetermined range including a radar image on which the selection symbol is superimposed,
Radar comprising selection symbol moving means for moving the selection symbol to a position closest to the ship position on the contour line of the radar image within the predetermined range and displaying the selection symbol superimposed on the display apparatus.

Images