JPH0226744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tidal current meter, and is intended to display temporal changes in tidal currents together with the ups and downs of the ocean floor on a cathode ray tube.

One of the most important pieces of information for fishing is the current situation. For example, many excellent fishing grounds exist in areas where tides form. However, the tidal currents near the tide usually have complicated movements, and when casting a fishing net, it is necessary to fully understand the difference in direction and size of the tidal current from the upper layer to the lower layer of the sea before casting the net. may become twisted or damaged. In recent years, ultrasonic current meters that utilize the Doppler effect of ultrasonic waves have been used to detect tides and measure mid-layer currents (for example, the
−23314). This is very convenient because the necessary information can be obtained only by transmitting and receiving ultrasonic waves. However, although this conventional device can determine the tidal current value at the current time, it is not suitable when you want to know the changes in the tidal current in a certain sea area or when you want to see the changes in the tidal current caused by the ups and downs of the ocean floor.

Furthermore, with conventional equipment, it was not possible to simultaneously three-dimensionally observe tidal current values at multiple depths.

The present invention attempts to graphically display past tidal current values in addition to instantaneous tidal currents three-dimensionally and continuously over multiple depths, and this will be described below with reference to embodiments.

FIG. 1 is a block diagram of the present invention.
T ₁ , T ₂ , and T ₃ are transducer groups that transmit and receive ultrasonic pulses diagonally below the bow and diagonally left and right behind the stern, respectively. Reference numeral 1 denotes an ultrasonic transmitting/receiving device for the above-mentioned transducer group. 2 is an A-D converter that converts the analog output of the transmitter/receiver into a digital output, and 3 is a central processing unit (hereinafter abbreviated as CPU). Reference numeral 4 denotes a fixed memory (ROM) in which format signals necessary for the display are stored in advance. Reference numeral 5 denotes a data memory that temporarily stores a tidal flow data signal obtained based on a reflected signal inputted from the transmitting/receiving device 1, and temporarily stores the calculation results of the CPU. Reference numeral 6 denotes a gyro compass for detecting absolute orientation, and its output is inputted to the CPU and data memory 5 via an AD converter 7. Note that 8 is a control panel connected to the CPU.

9 is a black-and-white conversion circuit that converts the format signal of the CPU output into a black-and-white video signal. 1
0 is a color conversion circuit that converts data output processed by the CPU into a predetermined color signal. Reference numeral 11 denotes a synthesizing circuit which synthesizes these two signals and inputs the synthesized signal to the cathode ray tube display 12.

The above device displays a graph as shown in FIG.
When the settings are made, the CPU 3 reads out the graph frame signal and scale signal stored in advance from the fixed memory 4 and supplies them to the black-and-white conversion circuit 9. The black and white conversion circuit 9
The input signal from the CPU is converted into a white level video signal of the cathode ray tube display 12 and supplied to the synthesis circuit 11. The synthesis circuit 11 inputs this signal to the signal input terminal of the cathode ray tube display 12 and displays the screen as shown in FIG.
Display white frames with scales as shown as G ₁ , G ₂ , and G ₃ . _G1 is for displaying the current speed of the current, _G2 is for displaying the direction of the current, and _G3 is for displaying the depth. Also, the time scale 0, 1, 2...5H, which is common to each frame, is graduated from right to left. Also G ₁ flow velocity scale (2.0KTS)
The depth scale (200M) of G3 and _G3 is designed so that the maximum scale can be changed by changing the resin. In addition to these graph frames, "ship speed" and "course" are displayed above them.
Data frames such as "flow speed", "flow direction", "setting", and "alarm speed" are displayed in white. Note that the CRT screen is black.

Next, regarding the display of each data, the following data processing is performed by pressing the "graph display" key on the control panel 8.

The transducers T ₁ , T ₂ , T ₃ are activated by the operation of the transmitting/receiving device 1.
The ultrasonic pulses sent in various directions from the ocean are reflected from the ocean floor and the plankton layer floating in each layer of the water, and the plankton layer moves at the same speed and in the same direction as the tidal current. It can be seen as such. Ultrasonic current meters focus on the fact that ultrasonic waves are subject to the ground Doppler effect (own ship's ground speed) and the water Doppler effect (own ship and water speed), and measure the ground current based on the difference between the two. . For details, please refer to JP-A-52-116272.

Now, the above-mentioned reflected wave signal is converted into a digital signal by the A/D converter 2 and stored in the data memory 5 via the CPU 3. And this memory data
Even after being processed by CPU3, it remains undeleted,
Subsequent reflected wave signals are also treated in the same way. On the other hand, the absolute direction signal from the gyro compass 6 is A-D.
The data is input to the data memory 5 via the converter 7 and the CPU. The data stored in these data memories are
It is called periodically by the CPU, and the speed and direction of the tidal flow in each layer are calculated using the well-known calculation method described above. The calculation output is further converted into a time signal for display and then supplied to the color conversion circuit 10.
The color conversion circuit 10 converts each layer of data into a display signal of a different color. For example, data at a depth of 5 m is converted to a yellow signal, data at a depth of 20 m, and data at a 40 m layer are converted to green and blue signals, respectively. On a cathode ray tube screen, these color signals are, for example, P ₁ , Q ₁ (yellow),
The dots, such as P ₂ , Q ₂ (green), P ₃ , and Q ₃ (blue), are displayed in each color at the corresponding positions of the flow velocity scale and flow direction scale. Moreover, the display is shifted to the left for a short time every time data is processed. As a result, as shown in FIG. 2, the tidal current and current direction are displayed graphically using a group of short and small dots. Note that P ₁ , Q _{1 ,} etc. are shown as enlarged short and short dots on the screen. on the other hand
The CPU's calculation output is displayed as white numerical values in the ``Ship Speed'', ``Course'', ``Current Velocity'', and ``Current Direction'' columns using a black-and-white conversion circuit. Furthermore, the observation device set in the transmitting/receiving device 1 is displayed in the "Settings" column. The correspondence between this numerical data and each depth layer in the graph display is made by coloring the numerical frames □1, □2, □3 in the numerical data column into yellow, green, blue, etc., respectively.

Next is the depth display of the seabed, as mentioned above,
Since tidal current information is obtained by transmitting and receiving ultrasonic pulses, the time interval between transmitting and receiving pulses represents the depth of the ocean floor. However, since the direction of the transmitting and receiving signals is diagonally downward, the CPU performs a correction calculation by the sine of the oblique angle θ, and the color conversion circuit 10 converts the result into a display signal of a color different from the flow velocity display color, and displays it on the cathode ray tube display. Supply to 12. This will cause the screen to display G ₃
A cross-sectional image of the ocean floor is displayed as shown in . For example, if the ocean floor is displayed on a flat surface,
Since it is not clear whether the seabed is actually flat or whether the ship is stopped, a distance (route) column is provided below the seabed depth display, and a mark D is inserted at each fixed cruising time. There is.

Furthermore, a "mode" display column M is provided between the graph display and the seabed depth display. This indicates whether the displayed tidal current is in the water mode or the ground mode. If the depth gradually increases and it becomes impossible to receive seabed reflected waves, for example, the color will turn brown for that period of time. The color changes from to blue B.

Using the above-mentioned device, an observer can grasp not only the instantaneous value of tidal currents in a certain sea area, but also the distribution of tidal currents in a three-dimensional manner for each depth layer. It also has the advantage of being able to obtain statistical data on the ups and downs of the ocean floor and changes in tidal currents.

In addition, differences in tidal currents depending on the layer are also induced by changes in water temperature. Therefore, the underwater tidal current distribution is almost the same as the underwater temperature distribution, as can be seen from the tides, and although it is not possible to measure accurate temperature, it is possible to determine the relationship between fish schools and water temperature. That is, the device of the present invention has a function as an underwater temperature distribution meter in addition to a tidal current meter.

In addition, in the example, the depth of the seabed is calculated not only from the data of the ultrasonic waves emitted diagonally forward and downward, but also by taking the average of the reflected waves from diagonally rearward and downward, which can significantly prevent fluctuations due to pitching and rolling. .

Further, in the embodiment, the seabed depth was obtained using ultrasonic pulses for measuring tidal currents, but it may be based on data obtained separately using an ultrasonic depth sounder.

Furthermore, since the flow velocity and flow direction data vary considerably from unit measurement to unit measurement, it is better to average the results of several measurements.

[Brief explanation of drawings]

FIG. 1 is a block system diagram of the apparatus of the present invention, and FIG. 2 is a display diagram showing an example of the screen of the cathode ray tube display of the apparatus of the present invention.

Claims (1)

[Scope of Claims] 1. A calculation device that continuously measures and calculates the flow speed and direction of tidal currents at multiple depths using ultrasonic waves, and changes over time in the flow speeds of multiple tidal currents that are the output of this calculation device. This tidal current observation device is provided with a mode mark display column for distinguishing whether the value is a value relative to the water or a value relative to the ground. 2. A calculation device that continuously measures and calculates the depth of the seabed in a given sea area and the current velocity and direction of tidal currents at multiple depths in that sea area using ultrasonic waves, and the current speed and direction of multiple tidal currents that are the output of this calculation device. In addition to displaying each change over time in the current direction in a color so that they can be distinguished from each other, a mode mark display field is provided to identify whether the value is relative to the water or to the ground. A tidal current observation device consisting of a display that displays changes in current speed and direction over time on a common time axis.