JPH0249179A - Position display radar equipment - Google Patents

Abstract

PURPOSE:To display a correct a latitude/longitude line by moving the latitude/ longitude line so that an image of a target whose latitude/longitude position on a display screen is known is positioned correctly against the displayed latitude/longitude line, and calculating an error from the moving amount. CONSTITUTION:On a position display radar equipment, a correction control part 42 is provided, and it is moved on a display screen so that a display position of a target whose latitude/longitude position is known in advance in an image of radar echo information coincides with correct latitude and longitude. From a shift of the longitude and the latitude before the movement and the longitude and the latitude after the movement, an error of measured position information stored in a position information storage part 16 is derived, and error information is stored in a storage part 43 of an arithmetic part 22. Subsequently, the measured position information is read out of the storage circuit 16, and a parameter operation of latitude and longitude lines is executed, while correcting the information by error information of the storage part 43.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radar device that repeatedly obtains F-information by transmitting and receiving radio waves while rotating the pointing direction of an antenna, and displays the echo information. This is an attempt to display images of nautical chart information in a superimposed manner.

If a nautical chart showing the latitude and longitude of the radar °- is superimposed on the display image of the radar, it will be possible to easily read the latitude and longitude positions of reflective objects around the moving object carrying the radar. It is possible and extremely convenient.

Conventional navigation devices that obtain position information, such as hyperbolic navigation devices, navigation devices that use radio waves from artificial satellites, and inertial navigation devices, can determine the location of a moving object in terms of latitude and longitude. It is possible to display latitude and longitude on the radar display screen. However, the measurement accuracy of conventional navigation devices is generally inferior to that of radar. Therefore, even if a part of the latitude and longitude lines are displayed on the radar display screen based on the latitude and longitude of the moving position of the moving object obtained by a conventional navigation device, the latitude and longitude line The latitude and longitude position of the reflecting object obtained from this method is accompanied by a considerable amount of error.

The purpose of this invention is to make it possible to superimpose and display fairly accurate latitude and longitude lines, that is, nautical chart information, on a radar display screen based on latitude and longitude positions obtained from a navigation device. It is.

According to this invention, the position of a moving object is determined as latitude and longitude using a navigation device, and based on the latitude and longitude, a nautical chart is superimposed and displayed on a radar display screen provided on the moving object. The latitude and longitude lines are moved so that the image of a target whose latitude and longitude positions are known in advance, such as Mt. Fuji, is positioned correctly relative to the displayed latitude and longitude lines. Calculate the error from the deviation. Calculation of nautical chart information based on the latitude and longitude information obtained from the navigation device is then performed while correcting it using the error information to obtain latitude and longitude information for display.

Alternatively, move the moving marker displayed on the radar display screen to an image whose latitude and longitude position is known in advance, such as Mt. Fuji, and compare this moving marker and the position of the moving object on the radar display screen. The latitude and longitude position of the moving object is determined from the difference between When calculating display latitude and longitude information from the above, correction is performed using the error information.

As described above, according to the present invention, by moving a part of the image on the display screen, an error in the nautical chart information on the display screen is detected, and correct calculation of the nautical chart information is performed based on the error information. This allows nautical chart information to be displayed superimposed on an image of radar echo information with high accuracy.

Next, the position indicating radar device according to the present invention will be explained in detail with reference to the drawings. In FIG. 1, a radar transmitting/receiving device 11 emits pulsed radio waves at a rate of several hundred times per second while rotating the pointing direction of a directional antenna 12 at a rate of, for example, 10 times per minute, and receives echoes from surrounding targets. Then, the echo information is transmitted by the coordinate converter 13, for example, from Gokuza Prefecture.
It is converted into XY coordinates and stored in the echo information storage circuit 14.

A navigation device 15 such as Roland, Omega, and NN5S that can receive and analyze all radio waves and measure the reception position of the radio waves as latitude and longitude is provided. The location information thus obtained is stored in the location information storage circuit 16. Also, the azimuth information of the moving body is detected by, for example, a gyro 17 of the moving body equipped with the radar device 11 and the navigation device 15, and is stored in the azimuth information storage circuit 18. The information stored in the position information storage circuit 16 and the azimuth information storage circuit 18 is input to the parameter calculation unit 22 in the chart information calculation device 21.

The parameter calculation unit 22 is set with information indicating the spacing between the latitude and longitude lines to be displayed by the setting circuit 19, and whether the latitude lines and longitude lines are to be displayed with a degree of coarseness. 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.

For example, as shown in FIG. 2, the parameter calculation unit 22 tries to display the position 24 of the moving body based on the position (XY) on the XY coordinates on the display screen, the longitude, latitude La, and direction information θ. Line of longitude 25, line of latitude 2
Calculate 6. The angles of these longitude lines 25 and latitude lines 26 with respect to the azimuth direction, that is, the Y-axis direction, are determined from θ, and each longitude displayed for the position 24 of the moving object is determined by the degree of accuracy, that is, the interval, in which the longitude and latitude are displayed. line 25
, and similarly the latitude lines 26 can be determined sequentially.

As mentioned above, these are determined 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. The latitude lines 26 are used as positions on the beginning and end of each line, or on the starting X.
The Y coordinate position and the slope information of each line are determined as parameters, and these parameters are provided 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.

The echo information storage section 14 and the nautical chart information storage section 28 are read out during raster scanning and synchronization of the raster scanning display 29, and the read echo information and nautical chart information are combined in a synthesis circuit 31 and supplied to the display section. displayed.

Therefore, on the display screen of the display device 29, for example, as shown in FIG. 3, an image 33 of a moving body is displayed in the center thereof, and an image 34 of land, for example, showing reflected objects from around the moving body, centered on this image 33. is displayed, the direction of the moving object, for example, the bow direction in the case of a ship, is displayed as a bearing line 35, and furthermore, for example, an image of another ship is displayed as 36. Similar to the conventional radar device, distance marks 37 are displayed in concentric circles with the self image 33 as the center. 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 NI K with distance mark 37,
The latitude and longitude positions obtained by the navigation device 15 are accompanied by relatively large errors.

This invention attempts to correct this error.

For this purpose, an image of a target whose latitude and longitude position is known in advance in the radar F-information image, for example, an image of Mt. Fuji 41 is used. For example, the display position 41 of a target that is known in advance is adjusted so that the longitude and latitude position displayed by the longitude 38 and latitude 39 on this display screen match the correct longitude and latitude of the target that is known in advance. line 38, latitude line 39
move on the display screen.

That is, for example, in FIG. 1, the correction control section 42 is provided,
X when calculating each parameter of longitude line 25 latitude line 26
By gradually shifting the reference position of the Y coordinate along the X axis or the Y axis by operating the correction control unit 42, the calculated parameters of each longitude line 25 and latitude line 26 are sequentially changed, The images of the longitude lines 38 and latitude lines 39 displayed on the display 29 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 as the target object from which this image 41 is obtained. The correction control unit 42 is controlled so that the longitude and latitude positions of the coordinates coincide with the previously known longitude and latitude positions.

The longitude/latitude position according to the displayed nautical chart information of this image 41 is matched with the original correct longitude/latitude position, and the longitude line 25 at 92 o'clock is
', the error in the measured position information stored in the position information storage unit 16 is determined from the deviation between the latitude line 26' and the longitude line 25 and the latitude line 26 before the movement. Error information indicating these deviations is stored in the storage section 43 in the parameter calculation section 22.

Measured position information inputted 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, displays the longitude and latitude of each point on the display screen with considerable accuracy. I will do it.

Note that the parameter calculation section 22 and the line information calculation section 27 can be constructed 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 drawing. 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 44 is displayed.

An error calculation section 46 is provided, and the error calculation section 46 can 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. 1 by the correction control section 42. In order to obtain the XY data of the movement change position, detection range information is given from the transmitting/receiving device 11 of FIG. The position of the moving marker 44 on the display screen can be moved by changing the marker display position.

This moving marker 44 is moved to match the image 41 of the object whose longitude and latitude are known in advance.

In this matched state, the correct distance between them is determined from the XY information of the generation section 45 of the moving marker 44 and the XY information of its own 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 image 33.41, and the direction information θ. , calculates the longitude and latitude of the moving object, and uses this and the navigation device 15
Calculate the error from the difference with the position information measured in . Alternatively, 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 read from the display section 51 and inputted as correction information in the parameter calculation section 22 in FIG. 1, or automatically inputted to the parameter calculation section 22 from the error information calculation section 46, Thereafter, this error information is taken into account, and four-dimensional longitude/latitude information is calculated from the position information, azimuth information, and other setting information, and is 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 a higher degree of correction can be performed than in the case of moving the latitude and longitude line image.

As described above, in the position display radar device according to the present invention, the display of the echo information and the display of the nautical chart information are superimposed, and the chart information is corrected; therefore, the echo information is obtained. As the means or means for obtaining position information, six different methods can be used.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a position display radar device according to the present invention, FIG. 2 is a diagram showing the relationship between the position of a moving object on XY coordinates and latitude and longitude, No. 316: Position information-storage circuit, 17 : Gyro, 18: Orientation information storage circuit, 19
: Latitude and longitude interval setting section, 21: Chart information calculation section, 22:
Parameter calculation unit, 27: Line information calculation unit, 28: Chart information storage unit, 29: Display unit, 31: Synthesis circuit, 42: Correction control unit, 43: Error information storage unit, 41: Object with known latitude and longitude position 44: moving marker; 45: moving marker generating section; 46: error information calculating section. FIG. 7 is a block diagram showing another example of obtaining error information. 11: Radar transmitting/receiving device, 13: Coordinate converter, 14:
Echo information storage unit, 15: Navigation device, left diagram

Claims (1)

[Claims] Means for storing echo information obtained by repeatedly transmitting and receiving radio waves while rotating a directional antenna in an echo memory circuit; means for storing position information included in radio waves received by an antenna of a navigation device in a position memory circuit; It has means for storing nautical chart information such as latitude and longitude in a nautical chart storage circuit, and a display control circuit and cathode ray tube installed to read out the stored information and obtain a video signal superimposed on targets around the own ship. A position display radar device characterized in that it obtains an image in which echo information and chart information are superimposed by operating electron beam deflection circuits in cooperation with each other.