JPH0160793B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image display method of a scanning sonar forming a received multi-beam.

(Prior Art) Conventionally, in scanning sonar, a receiving multi-beam method has been considered in order to shorten the time for searching for schools of fish. In this method, multiple receiving beams with different depression angles are simultaneously scanned conically (also called conical scan) in the azimuth direction to receive the waves, and the received signals for each depression angle are simultaneously extracted. This is an attempt to display images at the same time.

An example of this will be explained below.

Figure 3 shows a configuration block diagram of a scanning sonar that uses multiple receiving beams. Z ₁ , Z ₂ ,…
..., Z _o indicate received beams with different depression angles. Corresponding to the receiving beams Z ₁ , Z ₂ , ..., Z _o , the same number of phase shift receivers 4, 5 ..., 6 are provided.
is provided. Transducer 3 to each phase shift receiver
All conversion elements (transducers) that make up the
An electric signal is applied from the depression angle signal generator 7, and an depression angle control signal is applied from the depression angle signal generator 7 to give a fixed phase difference to the signals from each conversion element arranged in the depression angle variable direction. By combining the electrical signals to which the phase difference has been imparted in this manner, a receiving beam having an angle of depression determined by the arrangement interval of the conversion elements, the frequency of the sound wave, and the value of the phase difference is formed. Therefore, by adding depression angle control signals that give different phase differences to each phase-shifted receiver, a plurality of received beams Z ₁ , Z _{2 ,} ..., Z _o having different depression angles are formed. It turns out. The received signals for each depression angle thus obtained are subjected to beam width formation and scanning in the azimuth direction by the azimuth scanning circuits 8, 9, _. S ₂ ..., same
_So can be obtained. These signals are normally displayed on a cathode ray tube display 12 after being converted into a raster scan via a scan converter 11.

For transmitting waves, receive beam Z ₁ or the same
It is also possible to transmit with a wide beam width that includes Z _o , or to divide one transmitting pulse as shown in Figure 4 according to the number of receiving beams, and convert each division for each division. By controlling the phase difference of the electrical signal that supplies power to the element,
The transmission energy of one transmission pulse may be divided and transmitted so as to match the depression angle of the reception beam. Z ₁ , Z ₂ , ..., Z _o in Fig. 4 are the transmitting beams corresponding to the receiving beams Z ₁ , Z ₂ , ..., Z _o in Fig. 3 at the transmitter 1. This indicates that the area is under phase control.

Next, the signals thus obtained are devised so that they can be displayed as simultaneously as possible on a cathode ray tube display.

As an example, a case will be explained in which there are two receiving beams (Z ₁ and Z ₂ ). Figure 5 shows an example of a display on a cathode ray tube display.
3 displays the received image of the received beam _Z1 , and the display section 14 displays the received image of the received beam _Z2 .
In Figure b, the display unit 15 displays the received images of the received beams Z ₁ and Z ₂ in a superimposed manner, and the display unit 16 displays cross-sectional images of the received beams Z ₁ and Z ₂ in a specific direction. is displayed. In the figure, θ ₁ indicates the angle of depression of the received beam Z ₁ , θ ₂ indicates the angle of depression of the received beam Z ₂ , and r ₁ and r ₂ each indicate the distance to the target school of fish.

(Problems to be Solved by the Invention) However, in the display method described above, problems arise when the number of receiving beams increases.

First, in the display method shown in FIG. 5a, as the number of received beams increases, the display area per received beam becomes smaller, making observation difficult. Furthermore, as the number of display surfaces increases, a drawback arises in that it becomes difficult to understand the relationship between the displays. Also in the same figure b
In the display method described above, the video signals of multiple receiving beams are displayed in a superimposed manner on the display unit 15, so as the number of receiving beams increases, it becomes difficult to determine which receiving beam the video is from. It's coming. In addition, the display on the display unit 16 only displays cross-sectional images of each receiving beam in a specific direction, and as the number of receiving beams increases, the display area per receiving beam becomes smaller and the observation area becomes smaller. There is a problem in that it becomes difficult for a person to associate and understand the images captured by each receiving beam.

An object of the present invention is to reduce the image display area for each received beam even if the number of received beams increases, in view of the problems of the scanning sonar display method using multiple received beams. The object of the present invention is to provide a display method that allows images of schools of fish captured by each receiving beam to be observed in association with each other.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

That is, in a scanning sonar that forms a received multi-beam, there is a color signal conversion circuit that converts the received signal of each received beam into a different color signal, and a color signal conversion circuit that converts the received signal of each received beam into a different color signal, and a color signal conversion circuit that converts the received signal of each received beam into a different color signal. The output signal of the video synthesis circuit is applied to a color CRT display, so that the received signal from each receiving beam is the same in a different color to each receiving beam. This is a scanning sonar image display method that displays images on the image display screen.

(Function) Since the video display method of the present invention is configured as described above, the received signals from each receiving beam are converted into electrical signals for displaying different colors in the color signal conversion circuit.

The received color signals from each received beam thus obtained are combined in a video synthesis circuit so that the images from each received beam appear on the same video display screen.
This synthesized video signal is applied to a color video display using a color cathode ray tube, so the video captured by each receiving beam is displayed in a superimposed manner in a different color for each receiving beam on the video display screen. .

With such a display, it is possible to easily understand on the same display screen which images on the screen are generated by which receiving beams.

Furthermore, since the images generated by each receiving beam are displayed in a superimposed manner on the display screen, it is easy to understand whether or not there is a relationship between fish school images of different colors. When multiple images of different colors appear in close proximity, it indicates that there is a high possibility that the same school of fish is spreading in the depth direction; conversely, if it appears only in one color, it indicates that This display makes it easy to understand the state of the fish school, as it shows that the fish school is not very widespread.

(Example) Examples of the method of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing an example of the configuration of means for implementing the video display method of the present invention.

S ₁ , S ₂ , ..., S _o are the receiving beams Z ₁ ,
This is the received signal corresponding to Z ₂ , ..., Z _o . These received signals S ₁ , S ₂ , ..., S _o are sent to the color signal generator 1 that constitutes the color signal conversion circuit 17
8, 19, ..., 20 will be added. The color signal generator outputs the electric signals corresponding to red, green, and blue with a determined strength ratio so as to generate each determined color signal. This output signal changes according to the strength of the received signal while maintaining the strength ratio of the signals corresponding to red, green, and blue. The signals corresponding to red from each color signal generator are applied to the red signal combiner 22 of the video combining circuit 21, and the signals corresponding to green from each color signal generator are applied to the green signal combiner 2.
3, the signal also corresponding to blue is applied to a blue signal combiner 24. The red signal synthesizer 22, the green signal synthesizer 23, and the blue signal synthesizer 24 of the video synthesis circuit 21 synthesize the input signals and output the synthesized signals to each color input terminal of the color video display 25.

Regarding the method of synthesis in the image synthesis circuit 21, it is possible to perform synthesis such that the image signals from the received beam having the smallest depression angle are prioritized and displayed,
It is also easy to perform a combination of simple additions. The difference in how images appear due to the difference in composition method is as follows. Now, when the images from each receiving beam appear to partially overlap, and when prioritizing the images from the receiving beam with the smallest angle of depression, first select the receiving beam Z ₁ including the overlapping parts. The image is displayed in the color determined by the receiving beam _Z1 . Next, the image part of the receiving beam Z ₂ that protrudes from the image of the receiving beam Z ₁ is the receiving beam.
Z ₂ is displayed in the specified color, and the received beam is
Receiving beam that extends out of the video range of Z ₁ and Z ₂
Only the video portion of Z ₃ will be displayed in the color defined for receiving beam Z ₃ . This situation is illustrated in Figure 2a.

On the other hand, in the case of compositing by simply adding, the portion where the images overlap appears as a composite color, as shown in FIG. 2b.

(Effects of the Invention) As described above, the video display method of the present invention has the following features:
Since images received by receiving multi-beams having different depression angles are displayed in different colors on the same display screen, it is possible to easily understand which images are generated by which receiving beams. In particular, by selecting colors that give a sense of visual depth, such as by making the colors darker as the angle of depression increases, it is possible to more intuitively grasp three-dimensional information from images.

In addition, since the images from each receiving beam are displayed in a superimposed manner on the display screen, it is easy to understand whether or not there is a relationship between fish school images of different colors. If the fish are appearing in the same way, it is possible to obtain useful information to understand the extent of the fish school in the depth direction.
Conversely, it can also be seen that schools of fish that appear only in a single color do not have depth-wise expansion. As described above, the display method of the present invention has the advantage that it is possible to instantly grasp the state of a school of fish more accurately than conventional methods without missing a school of fish over a wide range of depression angles all around the azimuth direction. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of means for carrying out the method of the present invention, FIG. 2 is a diagram showing an example of image display by the method of the present invention, and FIG. Figure 4 is a block diagram showing the configuration of a scanning sonar. Figure 4 is a diagram showing the transmission pulse when transmitting is also performed using multiple beams in a scanning sonar that uses multiple receiving beams. Figure 5 is a diagram showing the conventional 2-receiving scanning sonar. FIG. 6 is a diagram showing a display example of a display method in the case of a beam. 1... Transmitter, 2... Transmission/reception switch, 3... Transducer/receiver, 4, 5, 6... Phase shift receiver, 7... Depression angle signal generator, 8, 9, 10... Azimuth scanning circuit , 11
... Scan converter, 12 ... Braun tube display, 13, 14, 15, 16 ... Display section, 17
...Color signal conversion circuit, 18, 19, 20... Color signal generator, 21... Image synthesis circuit, 22... Red signal synthesizer, 23... Green signal synthesizer, 24...
Blue signal synthesizer, 25...Color video display device.

Claims (1)

[Claims] 1. In a scanning sonar that forms a received multi-beam, a color signal conversion circuit that converts the received signal of each received beam into a different color signal;
A video synthesis circuit is provided for synthesizing the received color signals of each received beam from the color signal conversion circuit, and the output signal of the video synthesis circuit is applied to a color cathode ray tube display to convert the received signal from each received beam. A scanning sonar image display method characterized in that images are displayed on the same image display screen in different colors for each received beam.