JPS5848071B2 - CRT image display method in SONA - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater object detection device, and particularly to a sonar.

In general, a sonar is a device that emits ultrasonic waves or sound waves (hereinafter referred to as ultrasonic waves) in the horizontal direction to detect underwater objects such as schools of fish. It is well known that the PPI method (planar graphical display) is used to indicate the direction and distance of a school of fish on the video screen.

This method is very convenient because it allows you to know the direction and distance of a school of fish, but the drawback is that you cannot determine the depth.

A general fish finder in a box only detects vertically below the sea surface, so while it is extremely effective in knowing the depth of a school of fish with certainty, it does not know the direction and distance.

Therefore, it would be extremely convenient if we could express a combination of both, that is, show the direction, distance, and depth of a school of fish at the same time, since we would have all the data necessary to judge the situation.

In view of this point, the present invention provides a device that indicates the vertical direction in the lower half region of a cathode ray tube, and the direction and distance in the upper half region, and will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 shows an example of an image of a cathode ray tube. In FIG. 1, 1 is a part of the inner tube and 2 is an additional device.

The sonar part 1 consists of a transducer 3, a transceiver 4 button, a control indicator 5, etc., which have the same functions as a general sonar, and 2 is an additional device necessary to carry out the present invention. 6 is a transducer control unit, γ is a horizontal direction indicating synchronization circuit, 8 is a writing and reading device, and 9 is a storage device.

Here, the transducer control unit 6 includes a mechanism for rotating the transducer with appropriate directivity in the vertical direction.

That is, the transducer is rotated in a circular motion in the vertical axis direction, and ultrasonic waves are emitted into the water area below the own ship to explore the area.

The folded transducer can be rotated in any horizontal direction, that is, in the direction of the survey, as required, so that the entire lower water area can be surveyed.

During exploration, the transducer 3 is directed in any horizontal direction, for example, towards the bow (for convenience, 0 degrees), and while rotating the transducer in the direction from the bow to the stern, the control indicator 5 transmits and receives signals. The transmitting section of the transducer 4 is driven, and the transducer 3 transmits ultrasonic waves at a constant period.

The reflected waves from the seabed and fish schools return to the transducer 3,
The signal is applied to the control indicator 5 through the receiving section of the transmitter/receiver 4, and a vertical cross section of the exploration area is shown in a plan view on the image plane of the cathode ray tube.

Figure 2 is a modeled image of a case where the ocean floor is flat and there are schools of fish shaped like rugby balls, but the lower half of the CRT is a vertical section below the own ship. It shows an image of the seabed 11 and a school of fish 12 obtained by the process described in the previous section, where O is the origin and 10 is the sea surface.

Here, for fish school 12, periodic exploration pulses are sent seven times, and there is no reflected wave from the fish school for the first, sixth and seventh detections, but for the second to fifth pulses. It shows the state when the reflected waves of each school of fish were obtained, and the numbers in the figure are written corresponding to each exploration pulse.

In this way, the image of a school of fish becomes shaped like a rugby ball when two to five times are combined.

The seafloor has reflected waves from the first to seventh detections, and is flat as shown in the figure.

Since the vertical cross-sectional view can be displayed on the lower half of the CRT image plane, the present invention utilizes the upper half to indicate the direction and distance of the object. That's right.

That is, when the transducer control unit 6 sends a signal to the horizontal direction indication cycle circuit 7 in relation to the detection pulse, in response to this, the synchronization circuit 7 drives the writing and reading device 8.
A signal is sent to the storage device 9 to instruct the horizontal direction.

The detected underwater information, that is, the school of fish and the reflected signals from the seabed, is stored in the storage device 9 via the control indicator 5.

After a suitably determined period of time has elapsed, the control indicator 5
The writing and reading device 8 is activated by the signal from the storage device 9, and the signal stored in the storage device 9 is sent to the control indicator 5, which sequentially scans in each direction and changes the angle for each exploration pulse. The cathode ray tube is illuminated at an angle of θ (this angle is approximately half the full angle of directivity), and the school of fish 13 and the seabed 14 are illuminated as shown in Figure 2.
Draw a video of.

In this case, the fish school corresponds to the fish school at the bottom of the cathode ray tube, and 2
~ Corresponds to 5 detections.

As described above, the direction and distance of the object can be known from the image on the top half of the CRT, and the vertical cross section can be seen from the image on the bottom half, so by observing both, the amount of fish can be estimated. In addition to being useful for fishing, it is extremely effective for fishing as it allows you to clearly see the direction, distance, depth, etc. to your own boat.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for an embodiment of the present invention, where 1 is a part of the sonar and 2 is additional equipment necessary to carry out the present invention. Figure 2 shows an example of an image of a cathode ray tube implementing the present invention.
The upper half is a horizontal exploration image, and the lower half is an example of a vertical cross-section image.

Claims (1)

[Claims] 1 In a so-called spiral scanning sonar that simultaneously sends out transmission pulses in all vertical directions and rotates the receiving beam at high speed to display PPI on the cathode ray tube, the lower half of the image screen of the cathode ray tube displays a vertically downward cross-sectional figure. At the same time, the direction and distance of the reflector are displayed flatly in the upper half area.