JPS60162972A - Radar navigation device - Google Patents

Abstract

PURPOSE:To allow a ship to measure precisely its position without utilizing Loran navigation by displaying an electronic marine chart and a reference target (small island, lighthouse, etc.) on a CRT by a radar, and calculating and displaying the position of the ship in navigating. CONSTITUTION:Marine chart information is stored in an electronic chart storage device and the shoreline (b) is displayed on the CRT. Further, a radar echo of a PPI scanning type obtained by the radar is converted by a scan converter to make the radar echo (a) coincident with the marine chart information (b). At this time, the position o' (longitude and latitude) of the ship in the radar echo is calculated to display the position in navigating on the CRT. Further, the small island and lighthouse are regarded as reference targets (c) and (d) and the range Lc and direction thetac to the reference targets (c) and (d) in the movement of the ship are tracked, calculated, and displayed on the CRT. Therefore, the position of the ship is measured accurately on the basis of the radar echo and this measuring device is utilized even outside a service area of Loran.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radar navigation system that superimposes and displays an electronic nautical chart and a radar image on a CRT, and determines the position of a ship as latitude and longitude values using radar.

In general, as a conventional device in this building, as shown in the block diagram of FIG.
The i-indicator 3 displays, for example, coastlines and the like as already shown in the electronic nautical chart shown in FIG. 2 for explaining the conventional apparatus.

Positioning device 4 such as Loran that indicates the latitude and longitude of the own ship's position
There is one in which the measured value is displayed on the CR1 display 3 via the display controller 2. In this case, the measured own ship position is.

A symbol such as O in FIG. 2 is displayed at a corresponding point on the nautical chart displayed on the CR1 display 3. In addition, in this conventional device, a PPI scan type image signal obtained by the radar 5 is converted into a TV scan type image signal by a scan converter 6, and a π radar image centered at O, which is the own ship's position, is transmitted via a display controller 2. as CR1 indicator 3
will be displayed. FIG. 2a shows an example of the radar image.

Therefore, since the position of the radar image displayed on the screen of the CR1 display 3 is regulated by the positioning device 4, the radar image a does not match when viewed on an electronic chart, and when sailing along the coast, the position is regulated by the positioning device 4. This is a problem in terms of safe navigation.

Furthermore, if the positioning error of the positioning device 4 at a certain time and place is 16T in FIG. However, since the positioning error of the positioning device 4 generally varies depending on time and location, it is difficult to obtain stable performance over a long period of time with conventional devices. has.

In order to eliminate this drawback, the present invention does not directly determine the own ship's position from the beginning to the end of the voyage using a positioning device such as Loran, but uses radar to determine the own ship's position during coastal voyages. The purpose of this invention is to provide a radar navigation system which aims to improve the accuracy of measuring the own ship's position even if there is a problem, and this will be explained in detail below based on the drawings.

FIG. 3 is a block diagram showing an embodiment of the device of the present invention.
is an electronic chart memory, and 2 is a display controller.

3 is a CRT display, 5 is a radar for obtaining a PPI scan type video signal, 6 is a scan converter for converting into a television scan type video signal, 7 is a reference target tracker, and 8 is an acquisition controller. .

9 is a position calculator, 10 is a reference target memory, and II is an initial setting terminal of the acquisition controller 8.

The electronic nautical chart storage device 1 stores nautical chart information such as coastlines necessary for navigation, and this nautical chart information is transmitted to the television scan type CR1 display 3 via the display controller 2.

On the CRT screen, for example, the coastline in the diagram for explaining the present invention shown in FIG. 4, which corresponds to this nautical chart information, is displayed. On the other hand, the PPI obtained by radar 5
The scan type radar image is converted into a television scan type image by a scan converter 6 and is supplied to the display controller 2 . In this display controller 2, the own ship's position in the radar image is determined by the own ship's position 0' from the 9 position calculator 9, that is, the latitude.
Since it has an operation function to move the radar image to the position of longitude (〆0・, λo') and send the radar image to the CR1 display 3, the C
On the R'T screen, the own ship's position that changes moment by moment in the radar 5-image during navigation is shifted to the position of da0, λ0, which is the calculation result obtained by the two-position calculator 9, Ship position is displayed with high accuracy. In Figure 4,
This figure shows a state in which the radar image a on the CRT screen and the chart information match. The reference target memory 10 also stores targets such as small islands and lighthouses within the effective range of the radar 5.

For example, the latitudes c and d shown in FIG. 4 correspond to reference target positions as independent points.

Longitude (, f21'c, λC], (da d, λd),...
...memorize in advance. At least one reference target position may be prepared to be stored in the reference target storage.

The output signal of the reference target memory 10 is converted into a suitable symbol form via the display controller 2 and sent to the CR1 display 3. c, d obtained by radar 5 at this time
The position that the point image should show is always the own ship position.
, λ0·, the display controller 2 functions so that the positions K of the symbols at points c and d coincide with each other. The reference target tracker 7 receives the image output signal of the radar 5.

6- Reference target position C or d from own ship position O' shown in Figure 4
distance (LC or La) and direction (θ・. or θd
), which changes with each sweep of the image output signal of the radar 5. This technology tracks (L(!IθC) or (Ld+θd)), which changes with each sweep of the image output signal of the radar 5. This technology is a tracking function such as ARPA, which is already known as a collision prevention system. For the reference target tracker, we first explained the case where the tracking function is in a steady operating state, but at the time the reference target tracker starts operating,
It is better to measure the own ship's position accurately at that point in time, so the results of measuring the latitude and longitude (lo', λo') of the own ship using an appropriate side positioning means such as LORAN etc. Make use of it. The initial setting input terminal 11 is supplied with a positioning signal of (daoL, λo/) as a result of this measurement. At this time, the acquisition controller 8 selects the one closest to the own ship's position from the initial setting input terminal from among several reference target positions transmitted from the reference target memory 10, and obtains its distance and azimuth information. is output to the reference target tracker 7. The reference target tracker 7 corresponds to the output of the acquisition controller 8 at the start of its operation. The distance and direction from own ship position 0' to the reference target to be tracked, for example, Lc.

θ. Tracking of the image signal of the radar 5 corresponding to is started.

The position calculator 9 calculates the latitude and longitude of the self-sufficiency from the latitude and longitude of the reference target currently being tracked, which is transmitted from the acquisition controller 8, and the distance and direction of the reference target cloth from the own ship's position, which is also transmitted from the reference target tracker 7. The data is then displayed (not shown) and sent to the display controller 2.

Based on the latitude and longitude of the own ship's position transmitted from the position calculator 9, the display controller 2 generates a signal for displaying the own ship's position in an appropriate symbol on the CRT screen of the CRT display 3, as shown in FIG. is sent to the CRT display 3.Reference target tracker 7
continues to track the initially set reference target, and eventually becomes unable to track due to reasons such as an obstacle entering between the reference target and own ship, the reference target tracker 7 sends an alarm to the acquisition controller 8. The signal is transmitted, and the acquisition controller 8 uses the reference target tracker 7 to determine the distance and direction of the second closest reference target cloth to its own ship from among the reference targets stored in the reference target memory IO.
to ensure that self-sufficiency position measurements are not lost at all times.

Furthermore, the acquisition controller 8 constantly compares the distance between the own ship's position transmitted from the position calculator 9 and the position of the reference target stored in the reference target memory IO.

If a distance shorter than the distance from the own ship's position to the reference target currently being tracked appears within this distance, the distance and direction of the reference target cloth from the own ship's position is sent to the reference target tracker 7 to determine the reference target to be tracked. It is also possible to update the information to always display the best tracking and own ship position with high accuracy.

Note that the same effect can be obtained even if a plurality of reference targets are tracked by the reference target tracker 7 and the positions of these targets are calculated by the position calculator 9.

As explained above, according to the present invention, the own ship's position is measured based only on radar images without using a positioning device such as LORAN, so it can not only be used outside the service area of LORAN etc., but also electronically. The nautical chart and radar images are shown in Table 9 in good agreement, and the relative relationship between own ship's position and other radar images is displayed with high precision, making it especially useful for navigation in sea areas where position measurement accuracy is important, such as coastal navigation. The effects are remarkable.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional device. FIG. 2 is a diagram for explaining a conventional device, FIG. 3 is a block diagram of an embodiment of the device of the present invention, and FIG. 4 is a diagram for explaining the present invention. ■...Electronic chart storage, 2...Display controller, 3...
- CRT display k + 5...Radar, 6...Scan converter, 7...Reference target tracker, 8...Acquisition controller. 9...Position calculator, 10...Reference target storage device. Patent applicant: Japan Radio Co., Ltd.

Claims (1)

[Claims] An electronic chart storage device that electronically stores chart information, and the latitude of a target selected in advance as a reference target. a reference target storage device for storing reference target position information indicating longitude; a radar for obtaining a PPI scan type image signal;
It has a scan converter for converting an I-scan type image signal into a television scan type image signal, and a terminal for inputting a positioning signal of own ship's position for initial setting, and starts tracking the reference target closest to the own ship's position. an acquisition controller that sends out a distance and azimuth signal for the acquisition, and a reference target specified by the acquisition controller that is included in the distance, azimuth signal, and video signal of the radar for starting tracking obtained from the acquisition controller; a reference target tracker for tracking the reference target to obtain the distance and azimuth signal from own ship to the reference target; and position information of the reference target being tracked from the reference target memory and output of the reference target tracker. a position calculator for calculating own ship position, the chart information, and the reference target position information. Upon receiving the television scan image signal and the own ship's position from the position calculator, move the television scan image signal so that the own ship's position in the television scan image signal matches the own ship's position. What is claimed is: 1. A radar navigation system comprising: a display controller that generates a symbol at a reference target position and an own ship's position;