JPH035908Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention displays echo information obtained by a radar device and nautical chart information on the same display screen, and also displays echo information based on position information of targets known in advance. The present invention relates to a position display radar device that has a function of correcting the positional deviation between an image based on nautical chart information and an image based on nautical chart information.

``Prior art'' If a nautical chart showing the latitude and longitude of the radar is displayed simultaneously with the displayed image, it is possible to easily read the latitude and longitude positions of reflective objects around the moving object equipped with the radar. , is extremely convenient, and such a method has been proposed in Japanese Patent Application Laid-Open No. 53-52396.

``Problem to be solved by the invention'' In the above publication, it is only memorized that radar information and chart data (nautical chart information) are combined and displayed, and in a general chart, latitude and longitude lines are Because they are not drawn in detail, if the radar detection distance is short, only one latitude and longitude line will appear on the display screen, or in extreme cases, no lines will appear at all, making it difficult to read the radar image in terms of latitude and longitude. become unable to do so.

"Means for Solving the Problem" According to this invention, the interval between the latitude and longitude lines displayed on the display screen is set by the interval setting means, and information indicating the set interval and position information of the moving object, The position and inclination angle of the latitude and longitude lines on the display screen are calculated from the azimuth information of the moving body and the set radar detection distance information, and the nautical chart information is obtained by the nautical chart information calculation device. Therefore, in this invention, a plurality of latitude and longitude lines appear on the display screen at set intervals, regardless of the radar's set detection distance, and the latitude and longitude of each part of the radar image can be read.

"Example" Hereinafter, an example will be described with reference to the drawings. The radar transmitting/receiving device 11 emits pulsed radio waves at a rate of several hundred times per second while rotating the pointing direction of the directional antenna 12 at a rate of, for example, 10 times per minute, receives echoes from surrounding targets, and receives the echoes. The information is converted from, for example, polar coordinates to XY coordinates by the coordinate converter 13 and stored in the echo information storage circuit 14.

On the other hand, a navigation device 15 is provided which can measure the reception position of the radio waves as latitude and longitude by receiving and analyzing radio waves such as Loran, Omega, and NNSS. The position information thus obtained is stored in the position information storage circuit 16. In addition, these radar devices 1
1. Direction information of a moving body equipped with the navigation device 15 is detected by, for example, a gyro 17, and is stored in the direction information storage circuit 18. These azimuth information storage circuit 16 and azimuth information storage circuit 18
The information stored in is input to the parameter calculation section 22 in the chart information calculation device 21.

The parameter calculation unit 22 is set by the setting circuit 19 with information indicating the spacing between latitude and longitude lines to be displayed, that is, information indicating how rough the latitude and longitude lines are to be displayed.
Then, information indicating the detection distance at that time, that is, the relationship between the distance and area of the unit display screen on the display screen and the distance and area of the detection area, is input to the parameter calculation unit 22.

In the parameter calculation unit 22, for example, as shown in FIG.
Position on XY coordinates (x, y), longitude Lo, latitude
The longitude line 25 and latitude line 26 to be displayed are calculated from La and the azimuth information θ. These lines of longitude 2
5. Calculate the azimuth direction of the latitude line 26, that is, the angle with respect to the Y-axis direction from θ, and determine each longitude line displayed for the position 24 of the moving object depending on the degree of accuracy, that is, the interval, in which the longitude and latitude are displayed. 25
, and similarly the latitude lines 26 can be determined sequentially.

As mentioned above, these are obtained by referring to the accuracy settings of the latitude and longitude to be displayed and the radar detection range information, and these longitude lines 25 and latitude lines 26 are Find the XY coordinate position or the initial XY coordinate position and the slope information of each line as parameters,
These parameters are given to the line information calculation section 27.

The line information calculation unit 27 calculates information indicating each point to be displayed along the longitude line based on, for example, the start point and end point of each input longitude line 25, and similarly calculates information indicating each point to be displayed along the longitude line 25. Compute information indicating each point along the line. The calculated chart information, that is, longitude line and latitude line information, is stored in the chart information storage section 28.

Echo information storage unit 14 and chart information storage unit 28
are read out simultaneously in synchronization with the raster scanning of the raster scanning display 29, and the read echo information and nautical chart information are combined by a combining circuit 31 and supplied to the display 29 for display.

Therefore, on the display screen of the display device 29, for example, as shown in FIG. 3, an image 33 of the moving object is displayed in the center, and an image 33 of the moving object is displayed around this image, for example, reflecting objects from around the moving object, such as land. Image 34 is displayed,
Further, the direction of the moving body, for example, the bow direction in the case of a ship, is displayed as an azimuth line 35, and furthermore, for example, an image of another ship is displayed as 36. As with conventional radar equipment, the distance mark 37 is the self-image 33.
Displayed in concentric circles with the center at . Furthermore, longitude and latitude information is displayed as longitude lines 38 and latitude lines 39.

In this way, the nautical chart information is displayed superimposed on the echo information image of the radar device 11, and each position of the image of each target on the display screen can be read as latitude and longitude, which is extremely convenient.

However, in reality, compared to the accuracy of the distance mark 37, the latitude and longitude position obtained by the navigation device 15 has a relatively large error.

In order to correct the error, an image of a target whose latitude and longitude position are known in advance in the image of the radar echo information, for example, an image of Mt. Fuji 41 is used. For example, the displayed position 41 of the target object that is known in advance may be set so that the longitude and latitude position displayed by the longitude 38 and latitude 39 on this display screen matches the correct longitude and latitude of the target object known in advance. Line of longitude 38, line of latitude 39
move on the display screen.

That is, for example, in FIG.
2 is provided, and each of the parameters calculated by operating the correction control unit 42 and gradually shifting the reference position of the XY coordinates when calculating each parameter of the longitude line 25 and the latitude line 26 along the X axis or the Y axis. Each parameter of the longitude line 25 and the latitude line 26 is changed sequentially, and the display 2
The images of longitude lines 38 and latitude lines 39 displayed in 9 are freely moved vertically and horizontally, and the longitude and latitude positions of the image 41 based on the displayed longitude lines and latitude lines are determined in advance of the target object from which this image 41 is obtained. The correction control unit 42 performs control so that the longitude and latitude positions match the known longitude and latitude positions.

The difference between the longitude line 25' and the latitude line 26' before the movement and the longitude line 25 and the latitude line 26 when the longitude and latitude position according to the displayed nautical chart information of this image 41 is matched with the original correct longitude and latitude position. Then, the error in the measured position information stored in the position information storage section 16 is determined. Error information indicating these deviations is stored in the storage section 43 within the parameter calculation section 22.

Measured position information input one after another by the navigation device 15 is obtained from the storage circuit 16, and parameter calculations for longitude lines and latitude lines are performed in the parameter calculation section 22 while being corrected using error information in the storage section 43. Therefore, the nautical chart information on the display screen obtained based on the parameters corrected in this way, that is, the longitude line image 38 and the latitude line image 39, can accurately determine the longitude and latitude of each point on the display screen. will be displayed. Note that the parameter calculation section 22 and the line information calculation section 27 can each be configured using a so-called microcomputer.

Another example of correcting the displayed longitude lines and latitude lines is as follows. For example, as shown in FIG. 3, a moving marker 44 is displayed on the display screen. As shown in FIG. 4, XY information of the moving marker position to be displayed on the display screen is stored in the moving marker generating section 45, and the display position of this moving marker and the scanning position of the display 29 are constantly compared. When a match is found between the two, a display command is issued to the display 29 through the synthesis circuit 31, and the moving marker 4 is
4 is displayed.

An error calculation section 46 is provided, and the error calculation section 46 allows the correction control section 42 to freely change the display position of the moving marker 44 along either the X axis or the Y axis, as described with reference to FIG. In order to obtain the XY data of the movement change position, the transmitting/receiving device 1 of FIG. 1 is connected through the terminal 47.
Detection range information is given from 1, and the movement marker generating section 45 is given by the operation of the correction control section 42.
The position of the movable marker 44 on the display screen can be moved by changing the marker display position within.

The moving marker 44 is moved to match the image 41 of the target whose longitude and latitude are known in advance.
In this matched state, this moving marker 4
The correct distance L ₁ between them is determined from the XY information of the generation unit 45 of No. 4 and the XY information of the self-display information image 33. In addition, the correct longitude and latitude information known in advance of the image 41 is set in the setting section 48, and this is input to the error calculation section 46, and from this correct longitude and latitude, the distance between the images 33 and 41, and the direction information θ. , calculates the longitude and latitude of the moving object, and calculates an error from the difference between this and the position information measured by the navigation device 15. Or conversely, the longitude and latitude of the image 41 is determined from the longitude and latitude measured by the navigation device 15 and the distance and azimuth, and the error between this and the correct longitude and latitude is displayed on the display section 51. Position information is input to the error calculation unit 46 from the position storage circuit 16 through a terminal 49.

The error information obtained in this way is displayed on the display section 51.
It is read from the above and inputted as correction information in the parameter calculation section 22 in FIG. Parameters of longitude and latitude lines are calculated using the azimuth information and other setting information and output to the line information calculation section 27. In this case, the moving marker 44 can be correctly aligned with the known image 41, and therefore, correction can be performed with higher precision than when moving the latitude and longitude line images.

``Effect of the invention'' According to this invention, as described above, nautical chart information is formed by latitude and longitude lines, and the latitude and longitude lines are rotated according to the navigation direction of the moving object using azimuth information such as a dial. Therefore, even if the displayed image of the echo information from the radar device is different from the actual image on the nautical chart, if you rely on the latitude and longitude lines on the nautical chart, you will be able to see the north as shown in Figure 3. Even if the direction is tilted, it can be easily determined without making a mistake.

Furthermore, latitude and longitude lines appear on the display screen at intervals set by the interval setting means.In other words, regardless of the long or short radar setting detection distance, multiple latitude and longitude lines always appear at the same interval, and each part of the radar image can read the latitude and longitude of If you make the spacing between latitude and longitude lines small, you can accurately determine the latitude and longitude of each part, but there is a risk that the latitude and longitude lines will get in the way and make it difficult to see the radar image. Although the latitude and longitude lines are less likely to interfere with the radar image, the accuracy of reading the latitude and longitude of each part deteriorates. However, the spacing between the latitude and longitude lines can be freely set by the spacing setting means according to the requirements at the time.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a position display radar device according to this invention, Fig. 2 is a diagram showing the relationship between the position of a moving object on XY coordinates and latitude and longitude, and Fig. 3
The figure shows an example of a display image displayed by the apparatus according to this invention, and FIG. 4 is a block diagram showing another example of obtaining error information in the apparatus according to this invention. 11...Radar transmission/reception device, 13...Coordinate converter, 14...Echo information storage unit, 15...Navigation device, 16...Position information storage circuit, 17...Gyroscope, 18...Direction information storage circuit, 19 ...Latitude and longitude interval setting section, 21...Nautical chart information calculation section, 22
...Parameter calculation section, 27...Line information calculation section,
28...Nautical chart information storage unit, 29...Display unit, 31
. . . Synthesis circuit, 42 . Error information calculation section.

Claims (1)

[Claims for Utility Model Registration] A radar device section for obtaining echo information based on echoes detected from targets around a moving body, and a position in latitude and longitude based on the position obtained by measuring the position of the moving body. a navigation device section for obtaining information; a direction detection device section for detecting the direction of the moving object and obtaining direction information; and storing figures and latitude and longitude lines related to the nautical chart near the position of the moving object as chart information. a raster-type display unit having a display screen for displaying an image based on the echo information (hereinafter referred to as an echo image); , referred to as a nautical chart image) and the echo image in a superimposed manner, comprising: an interval setting means for setting interval information indicating an interval between latitude and longitude lines displayed on the display screen; and the position information. , the azimuth information, the interval information, and the detection distance information set in the radar device section are input, and the positions and inclination angles of the latitude and longitude lines to be displayed on the display screen are calculated and obtained. A position display radar device comprising: a nautical chart information calculation device that stores information as the nautical chart information in the nautical chart information storage unit.