JP2000314741A - Power flow display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power flow display device allowing to intuitively and easily recognize flow speeds and flow directions of power flow in multiple layers. SOLUTION: Display areas 31, 32, 33,... for individual layers are arranged in the vertical direction on a power flow display part 1. Power flow vectors 10 for the individual layers presented with an azimuth circle and a line are individually displayed in the individual display areas. The power flow vectors 10 for the individual layers are displayed in colors corresponding to flow speeds of power flows. This constitution allows to visually and intuitively recognize the flow speeds and the flow directions of the currents across multiple layers. It also allows to identify the flow speeds at a glance since the power flow vectors are displayed in the colors corresponding to the flow speeds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tidal current display device of a tidal current meter for measuring the flow velocity and direction of a tidal current by emitting an ultrasonic wave into water and receiving its echo signal.

[0002]

2. Description of the Related Art A tidal current meter measures the flow velocity and direction of a tidal current using the Doppler effect of ultrasonic waves. In such a Doppler tidal current meter, an ultrasonic beam is emitted from a transmitter / receiver mounted on the bottom of the ship with a depression angle in, for example, three directions, and the frequency of an echo signal reflected back in water and measured is measured. Then, a deviation (Doppler shift) between this frequency and the frequency of the emitted beam is detected, and arithmetic processing based on this detection result is performed to obtain the flow velocity and direction of the tidal current, and these are displayed on a display.

FIG. 8 shows a display screen of a conventional power flow display device. In the figure, a tide display section 51 is provided on the display screen, and various data relating to the tide are displayed on the tide display section 51. Reference numeral 52 denotes a character display unit that displays the flow velocity, depth, and flow direction (azimuth) of the tidal current in characters, a display unit 52a that displays the tidal current data of the first layer,
A display section 52b for displaying the data of the tidal current of the second layer;
And a display unit 52c for displaying data of the tidal current of the layer.
For example, in the display unit 52a, “1.0kt” is the first
The velocity of the tidal current is 1.0 knots,
“2” indicates that the depth of the tidal current in the first layer is 2 m,
“ENE” indicates that the flow direction of the tidal current in the first layer is east-northeast.

Reference numeral 53 denotes a vector display unit for displaying the flow velocity and flow direction of the tidal current as vectors, and includes an azimuth circle 54 and tidal current vectors 55a to 55 displayed inside the azimuth circle 54.
c. The power flow vectors 55a to 55c represent the flow velocity of the power flow by the length of the vector, and the flow direction of the power flow by the direction of the vector. For example, the tidal current vector 55a has a length corresponding to a flow velocity of 1.0 knots and is oriented east-northeast. That is, this tide vector 5
5a is the first character displayed on the display part 52a of the character display part 52.
It shows the tidal current data (flow velocity and current direction) of the stratum.
Similarly, the tidal current vector 55b displays the tidal flow data of the second layer displayed on the display unit 52b, and the tidal flow vector 55c displays the tidal flow data of the third layer displayed on the display unit 52c. .

[0005] Reference numeral 56 denotes a depth display section for displaying the depth of the tidal current as a bar, and a bar 56a is a first display section displayed on the display section 52a.
The depth (2 m) of the tidal current is displayed. Similarly, a bar 56b indicates the depth of the tide of the second layer (30 m), and a bar 56c indicates the depth of the tide of the third layer (8 m).
0m). Reference numeral 57 denotes a tidal difference display section for displaying the tidal difference of each layer.
The difference (flow velocity difference, azimuth difference) between the tidal current of the layer and the three layers is displayed.

Reference numeral 58 denotes a school of fish display, which displays a school of fish 59 captured by each received beam. Numeral 60 denotes an oscillating line for emitting ultrasonic waves (position of a transducer), 61 denotes a depth scale, 62 denotes a depth of the seabed, and 63 denotes an echo depth range.

On the display screen, in addition to the above, a true ship speed display 6
4, a true course / direction display 65, a heading direction display 66, an operation mode display 67, a mode selection display 68, a flow rate range 69, and the like.

FIG. 9 shows a state in which the display screen of FIG. 8 is switched to another display screen. This switching is performed by a switching key (not shown). 9, reference numeral 70 denotes a character display unit corresponding to the character display unit 52 in FIG. 8, and a display unit 70a for displaying the data of the first layer tidal current and a display unit 70b for displaying the data of the second layer tidal current. And a display unit 70c for displaying the tidal current data of the third layer. In each display unit, numerals 1, 2, and 3 surrounded by squares represent layer numbers, respectively. Reference numeral 71 denotes a cruising distance (trip) display unit, reference numerals 72 and 73 denote ship position display units, and 72 indicates latitude and 73 indicates longitude.

A wake display unit 74 displays a wake line 75 indicating the wake of the ship, and a tide vector 76 at each point of the wake. The tide vector 76 is shown in FIG.
Current vector 55a displayed on the vector display unit 53
55c, and the flow velocity and direction of the tidal current for each layer are displayed as a history along with the wake. 77 is a mark indicating the current position of the ship, 78 is a ship speed vector (true course), 7
9 is a cursor line, 80 is a distance scale, 81 is a navigation device selection display section, and 82 is a plotter range. In FIG. 9, the same parts as those in FIG. 8 are denoted by the same reference numerals.

[0010]

In the above-described tidal current display device, the flow velocity and direction of the tidal current for each layer are displayed by characters and vectors. However, the display as shown in FIG. 8 lacks intuitiveness because the character display unit 52 can only grasp the flow velocity and flow direction of the tidal current for each layer by numerical values, and lacks intuition. Although it can be visually grasped by the vector, since the tidal current vectors 55a to 55c of each layer are drawn together in the same azimuth circle 54, it is difficult to intuitively grasp the flow velocity and flow direction of each layer. Also, the displayed flow rate
The current direction is data only at the present time, and is not displayed continuously in time. Therefore, it is not possible to grasp the temporal change of the tidal current.

On the other hand, in the display as shown in FIG. 9, by displaying the history of the tidal current vector 76 together with the wake line 75, it is possible to grasp the change in the location of the tidal current. However, in FIG. 9, similarly to FIG. 8, the character display unit 70 can only grasp the flow velocity and flow direction of the tidal current for each layer by numerical values, and thus lacks intuition. In the wake display unit 74, the tidal current vector 76 Are drawn together on the wake line 75, which makes it difficult to intuitively grasp the flow velocity and flow direction of each layer.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a tidal current display device capable of easily and intuitively grasping the flow velocity and direction of the tidal current for each layer.

[0013]

In order to solve the above-mentioned problems, the present invention provides a display area for each layer arranged in a vertical direction, and individually displays a tidal current vector of each layer in each display area. This tidal current vector is displayed in color in correspondence with the flow velocity. By doing so, the tidal flow vector can be displayed independently for each layer, so that the flow velocity and flow direction for each layer can be intuitively grasped visually. Further, the flow velocity of the tidal current can be clearly identified by the color.

Here, when a plurality of display areas are provided in the horizontal direction, the tidal current vector can be continuously displayed for each layer over time, and a two-dimensional display can be used to easily grasp the temporal change of the tidal current. can do.

[0015] The display form of the tidal current vector is as follows.
It can be composed of an azimuth circle, a sign indicating the horizontal flow direction shown inside the azimuth circle, and a sign indicating the vertical flow direction shown outside the azimuth circle. According to this display mode, not only the horizontal direction but also the vertical flow direction can be grasped.

Further, if a fish school display section is provided on the display and a tidal current display area is provided corresponding to the water depth in the fish school display section, the relationship between the fish school and the tide can be easily grasped.

Further, it is possible to selectively display a power flow vector indicating a horizontal flow direction and a power flow vector indicating a vertical flow direction. According to this, since only the necessary flow direction is displayed, the display becomes more visible.

Further, a tidal current vector can be displayed by designating a range. According to this, it is possible to extract and display only the tidal current vector that satisfies the condition of the specified range.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a display screen of a power flow display device according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a tide display unit, and a fish school display unit 7 is provided alongside the tide display unit 1. The tidal current display unit 1 is provided with a flow velocity range display unit 2 that displays a flow velocity range for each color, and a vector display unit 3 that displays a tidal current vector.

In the flow velocity range display section 2, five ranges are provided in which the flow velocity value is divided every 0.5 knots, and the ranges are blue, green,
It is colored yellow, orange, and red.

The vector display section 3 is provided with display areas 31, 32, 33,... For each layer arranged in a vertical direction, and a plurality of display areas 31, 32, 33,. (11 columns in the figure)
Layer display section 31a, second layer display section 32a, third layer display section 3
3a,...

FIG. 2 is a diagram showing the power flow vectors displayed in the display areas 31, 32, 33,. The tidal current vector 10 is composed of an azimuth circle 4 indicating an azimuth, a straight line 5 represented inside the azimuth circle 4, and a straight line 6 represented outside the azimuth circle 4. The straight line 5 is a straight line that extends in the radial direction from the center of the azimuth circle 4 and has a length equal to the radius of the azimuth circle 4, and is a symbol representing the flow direction in the horizontal direction. FIG. 2 (a)
In FIG. 2, the straight line 5 indicates the southwest direction, and in FIG. 2B, the straight line 5 indicates the northwest direction.

The straight line 6 is a straight line that is tangent to the azimuth circle 4 on the right side of the azimuth circle 4, and is a symbol representing the vertical flow direction. When the straight line 6 is on the upper right as shown in FIG. 2A, it indicates that the flow direction is upward, and when the straight line 6 is on the lower right as shown in FIG. 2B, the flow direction is downward. Is shown. Thus, the tidal current vector 10 is
The display is easy to see by expressing with the straight lines 5 and 6, and the flow direction in the vertical direction as well as the horizontal direction can be displayed.

The azimuth circle 4, the straight line 5, and the straight line 6 are displayed in colors shown in the flow velocity range unit 2 according to the flow velocity in the horizontal and vertical directions, respectively. For example, when the azimuth circle 4 and the straight line 5 are displayed in yellow and the straight line 6 is displayed in orange, the horizontal flow velocity of the tidal current is 1.0 to 1.5 knots, and the vertical flow velocity is 1.5 to 2.0 knots. It is within the range of knots. By displaying the tidal current vector 10 in a color corresponding to the range of the flow velocity, the flow velocity can be easily grasped visually.

Each display area 3 of the vector display section 3 of FIG.
The power flow vector 10 as described above is individually displayed for each layer in 1, 32, 33,... Here, the current tide information is displayed in the display area of the rightmost column X1.
Then, the information displayed in the rightmost column X1 shifts to the column X2 on the left after a predetermined time, and the current flow information at the present time is newly displayed in the column X1. Then, after a certain period of time, the information displayed in X2 moves to the column X3 on the left, and the information displayed in X1 moves to column X2, and the column X1
Displays new current tide information.

As described above, the latest power flow information is always displayed in the column X1, and this is sequentially shifted leftward as time elapses, so that the power flow vector 10 of each layer is continuously displayed with time. Will be done. in this way,
By providing a plurality of display areas 31, 32, 33,... In each layer in the horizontal direction to form a two-dimensional display form, and displaying the tidal current vector 10 of each layer continuously over time, the time of the tidal current in each layer can be reduced. The change can be easily and comprehensively grasped.

The tide display unit 1 has a depth scale 12
Is displayed, and the depth scale 12
Layer display section 31a, second layer display section 32a, third layer display section 3
3a,... Indicate the depth of each layer.

On the other hand, in FIG. 1, an echo signal is displayed as a school of fish 9 and a seabed 11 on the school of fish display unit 7 together with the oscillation line 8. Reference numeral 13 denotes a depth scale, and a tidal current display unit 1
Is the same scale as the depth scale 13. That is, the display areas 31, 32, 33,... Of each layer of the tidal current display section 1 correspond to the water depth in the fish shoal display section 1, so that the tidal current display section 1 and the fish shoal display section 7
By comparing them, the state of the tidal current in the layer where the school of fish 9 is present can be seen at a glance, thereby making it possible to accurately judge how to insert the net or the fishing line.

Although not shown, the display device is provided with a display section for displaying the ship speed, course, heading and other information in addition to the above.

In order to perform the display as shown in FIG. 2 on the power flow display unit 1, several dots (N dots) are required for one power flow vector 10 in the horizontal direction on the screen. On the other hand, since the fish finder image of the fish school display section 7 may be one dot, the fish school display section 7 may be displayed by enlarging it N times in the horizontal direction or the tide display section 1 may be displayed once every N times. , The tidal current vector 10 can be clearly displayed.

In the tidal current display device having the above-described display screen, the display areas 31, 32, 33,.
Are arranged in the vertical direction, and each of the display areas 31, 32, 33
Since the tidal current vectors 10 of the respective layers are individually displayed in..., The flow velocity and flow direction of the tidal current of each layer can be easily and intuitively grasped as compared with the conventional one. Also, since the tide vector 10 is displayed in color corresponding to the flow velocity,
The magnitude of the flow velocity can be clearly identified by the color.

Instead of displaying the horizontal flow direction and the vertical flow direction simultaneously as shown in FIG. 2, it is also possible to selectively display only one of them. This selection can be made by a selection switch (not shown). In this way, only the necessary flow direction is displayed, so that the display becomes more visible. In this case, the horizontal flow direction is indicated by an azimuth circle 4 and a straight line 5 as in FIG. 2, and the vertical flow direction is indicated by an arrow as shown in FIG.
What is necessary is just to display by the triangle mark like (b).

The display can be performed by specifying a range. For example, specify "place where the horizontal flow direction is northward (azimuth angle 340 ° -20 °)" or "place where the horizontal flow velocity is 0.5 knots or more" and display the tidal current vector at that place I do. According to this, it is possible to extract and display only the tidal current vector that matches the specified condition.

FIG. 3 is a block diagram showing an electrical configuration of the power flow display device according to the embodiment of the present invention. In the figure,
Reference numerals 20a, 20b, and 20c denote tidal current measuring transducers mounted on the bottom of the ship, and as described at the beginning, ultrasonic signals are emitted from the respective transducers in beams in three directions with depression angles. . Further, each of the transducers 20a, 20b, 2
0c receives the echo signal reflected and returned in the sea. 21a, 21b, 21c are transmitting / receiving units,
Ultrasonic waves are transmitted from the seas 0a, 20b, and 20c into the sea, and the signals received by the transducers are received to detect the Doppler shift. Details of the transmission / reception units 21a, 21b, 21c will be described later.

Reference numeral 22 denotes an arithmetic processing unit that receives outputs from the transmission / reception units 21a, 21b, and 21c and performs arithmetic processing on the flow velocity and flow direction of the tidal current. Display control unit to perform, 2
Reference numeral 4 denotes a screen memory for storing display data from the display control unit 23, and reference numeral 25 denotes a display such as a CRT for displaying the data stored in the screen memory 24 on the screen. The above elements are the elements that make up the tide meter.

Numeral 26 designates a transmitter / receiver for detecting a school of fish mounted on the bottom of the ship, which emits an ultrasonic beam into the sea and receives an echo signal reflected by the school of fish and returned. 27 is a transmitting / receiving unit for transmitting / receiving an ultrasonic signal to / from the transducer 26,
Reference numeral 8 denotes a display control unit that performs control for displaying fish school information detected by the transmission / reception unit 27, and 29 denotes a screen memory that stores display data from the display control unit 28. The data stored in the screen memory 29 is It is displayed on the screen of the display 25. The above elements are elements that constitute a fish finder.

Reference numeral 30 denotes an operation unit provided with various switches and keys, and 31 denotes a CPU (Central Processing Unit) for controlling each unit of the apparatus. A signal from the operation unit 30 is input to the CPU 31. A trigger signal is given from the CPU 31 to the transmission / reception units 21a, 21b, 21c on the tide meter side and the transmission / reception unit 27 on the fish finder side. Based on the trigger signal, ultrasonic waves are transmitted from the transducers 20a, 20b, 20c, 26. A detection pulse is fired.

The output of the CPU 31 is also supplied to the display control unit 23 on the tide meter and the display control unit 28 on the fish finder, and the output is used to switch the range and screen on the display 25, or the image feed speed. Is performed.

In the above configuration, the display 25 has the configuration shown in FIG.
The screen shown in is displayed. That is, the screen memory 24
The screen of the tidal current display unit 1 of FIG. 1 is displayed based on the data on the tidal current stored in the, and the screen of the fish shoal display unit 7 of FIG. 1 is displayed based on the data on the school of fish stored in the screen memory 29. To selectively display the horizontal flow direction and the vertical flow direction described above, when a selection switch (not shown) provided on the operation unit 30 is operated, the control display unit 23 via the CPU 31 is operated. Is given a signal, and the flow direction is selected and displayed. Further, in the case of performing the display by the above-mentioned range designation, when designation information is inputted by an input key (not shown) provided on the operation unit 30, a signal is given to the control display unit 23 via the CPU 31, and the input is performed. A tidal current vector that matches the specified condition is displayed.

FIG. 4 shows the transmitting / receiving sections 21a, 2a and 2a in FIG.
It is a block diagram which shows the specific structure of 1b, 21c.
Since the configurations of the transmission / reception units 21a, 21b, and 21c are the same, FIG. 4 shows only the transmission / reception unit 21a. In the figure, 32 is a transmitter, 33 is a receiver, 34 is a transmission / reception switch for switching between a transmission operation by the transmitter 32 and a reception operation by the receiver 33, 35 is an oscillator for generating a reference clock signal, and 36 is a receiver 33 A phase difference detector 37 for detecting a phase difference between the received signal received by the oscillator 35 and the reference signal from the oscillator 35, and a sampling clock 37 supplied from the oscillator 35 to the phase difference data output from the phase difference detector 36. Is a memory that latches based on

Next, the operation will be described. When a burst signal is transmitted from the transmitter 32 in a state where the transmission / reception switch 34 is switched to the transmission side, the transmitter / receiver 20a receives this and transmits an ultrasonic detection pulse into the sea. The echo signal of the transmitted detection pulse is received by the transmitter / receiver 20a, and is input as a reception signal to the receiver 33 via the transmission / reception switch 34 switched to the reception side.

The receiver 33 generates a zero cross signal from the received echo signal, and outputs this to the phase difference detector 36. On the other hand, a reference clock signal composed of a pulse train is supplied from the oscillator 35 to the phase difference detector 36, and the phase difference detector 36 detects a phase difference between the reference clock signal and the zero-cross signal from the receiver 33. Phase difference detector 3
6 outputs data of the detected phase difference, and the phase difference data is written to the memory 37 in accordance with the sampling clock from the oscillator 35. The phase difference data written in the memory 37 is a quantized phase difference value of an echo signal generated in the sea and on the sea floor with respect to the reference clock signal. This data is sent to the arithmetic processing unit 22 in FIG.
The speed and the like of the tidal current are calculated based on the phase difference data. The arithmetic processing unit 22 includes three transmission / reception units 21a, 21b, and 21c.
The calculation is performed on the basis of the phase difference data from, and the calculation results are combined to calculate the flow velocity and the flow direction of the tidal current.

Here, in order to measure the tidal current continuously over multiple layers as shown in FIG. 1, a fast Fourier transform (FFT) technique is used in the arithmetic processing of the arithmetic processing unit 22. The details thereof are described in the specification of an international application (international publication number: WO91 / 14953) by the present applicant, and the outline is as follows.

When an ultrasonic wave having a frequency f ₀ is emitted obliquely downward at a depression angle θ from a ship traveling at a ship speed V, the Doppler shift frequency fd of the echo signal from the sea floor is:
It is expressed by the following equation. fd = 2V · f ₀ · cos θ / c (1) where c is the speed of sound. From the above equation, the boat speed V is expressed as follows: V = fd · c / (2f ₀ · cos θ) (2) Therefore, if the Doppler shift frequency fd is known from the detected echo signal, the boat speed can be obtained.

In obtaining the Doppler shift frequency fd, the arithmetic processing unit 22 performs a predetermined Fourier transform on the phase difference data from the phase difference detector 36, and based on the resulting Fourier spectrum, obtains the Doppler shift frequency fd. To determine.

That is, the phase of the zero-cross signal generated from the echo signal at time t is θe (t),
Assuming that the phase of the reference clock signal is θp (t), the phase difference output from the phase difference detector 36 is Δθ (t) = θp (t) −θe (t) (3) Phase difference quantization value Δ
θw (t) and the phase difference quantized value Δθg (t) of the echo signal generated on the sea floor are obtained from Expression (3) by detecting each echo signal.

Here, if the measurement start depth and the measurement time width are set in advance in the arithmetic processing unit 22, the above Δθw (t) and Δθg corresponding to these set data are set.
(T) is required. The phase difference data thus obtained is subjected to trigonometric function conversion to obtain time-series data, which is multiplied by a Hanning window, subjected to a Fourier transform, and further subjected to frequency interpolation, thereby obtaining an echo signal generated at a certain depth or the sea floor. The Doppler shift frequency fd is determined. In this way, the tidal current can be measured continuously over multiple layers regardless of the number of layers.

When the Doppler shift frequency fd is determined, the ship speed to the ground and the ship speed to the water are obtained by the above equation (2). The ship speed to ground is obtained from the Doppler shift frequency based on Δθg (t), and the ship speed to water is obtained from the Doppler shift frequency based on Δθw (t). Then, the arithmetic processing unit 22 calculates the tidal flow velocity Vc in an arbitrary layer by the following equation based on the ground boat speed Vg and the water boat speed Vw. Vc = Vg-Vw (4)

Although the preferred embodiment of the present invention has been described above, the present invention can adopt various forms other than the above. For example, the circle representing the azimuth circle 4 does not necessarily have to be a perfect circle as shown in FIG. 2, and may be a polygon such as a hexagon as shown in FIG. 5A or an octagon as shown in FIG. Or an ellipse. Claim 3
Is a concept including all of them.

When the horizontal flow velocity is displayed in color,
Instead of displaying the circumference of the azimuth circle 4 and the straight line 5 in color, the azimuth circle 4 may be displayed in color so that the entire azimuth circle 4 is painted. By doing so, the color display area increases, and the flow velocity can be more easily identified. In the case where the above-described range is designated and the tidal current vector is displayed, the tidal current vector in the designated range is represented by a contour line. Displayed as an image. Further, instead of the straight line 5, a symbol such as an arrow or a triangle may be used.

In the case of representing the vertical flow direction, the straight line 6 in FIG. 2 may be on the left side or upper and lower sides of the azimuth circle 4, and a display form as shown in FIG. 6 is employed instead of the display form in FIG. You can also. 6 (a) and 6 (b) show the upward flow direction with the triangle or saddle-shaped symbol facing upward. In this case, too, the triangle and saddle portions are changed according to the flow velocity. Is displayed in green, for example, and the azimuth circle is painted in orange, for example, so that the display is easy to see. However, the display mode is not limited to this, and only the symbol and the outline of the azimuth circle may be colored. FIG. 6C shows the upward flow direction by having a semicircle in the upper half, and FIG. 6D shows the upward flow direction by having a solid line in the upper half.

In the above-described embodiment, the magnitude of the flow velocity is displayed by differentiating colors, but this may be displayed by shading, and the color display in claim 1 includes such a shading display. It is a concept.

In the above-described embodiment, the fish school display section 7 is based on the signal received by the fish detection / transmitter / receiver 26.
Although the school of fish 9 is displayed, the school of fish 9 may be displayed on the school of fish display unit 7 instead of this by receiving a wave signal from one of the transducers 20a, 20b, and 20c for measuring the tidal current. In this case, the emitted ultrasonic beam is oblique,
The arithmetic processing unit 22 corrects the distance.

[0054]

According to the present invention, the display is provided with a display area for each layer arranged in the vertical direction, and the power flow vector of each layer is individually displayed in each display area. The flow velocity and flow direction can be intuitively grasped visually. Moreover, since the tidal current vector is displayed in color in correspondence with the flow velocity, the flow velocity can be identified at a glance.

Also, a plurality of display areas are provided in the horizontal direction,
By using the dimensional display, the tidal current vector can be continuously displayed over time for each layer, and the overall situation of the tidal current can be grasped at a glance.

Further, by forming the tidal current vector with an azimuth circle, a sign indicating a horizontal flow direction, and a sign indicating a vertical flow direction, both the horizontal and vertical flow directions can be grasped.

Further, by providing a fish school display section on the display device and providing a tide display area corresponding to the water depth in the fish school display section, it is possible to easily grasp the relationship between the fish school and the tide.

Further, by selectively displaying the tidal flow vector indicating the horizontal flow direction and the tidal flow vector indicating the vertical flow direction, only the necessary flow direction is displayed, and the display becomes more visible. Further, by displaying the tidal current vectors in the specified range, only the tidal current vectors that match the conditions can be extracted and displayed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a display screen of a power flow display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a power flow vector.

FIG. 3 is a block diagram showing an electrical configuration of the power flow display device according to the embodiment of the present invention.

FIG. 4 is a block diagram illustrating a specific configuration of a transmission / reception unit.

FIG. 5 is a diagram showing another display mode of a tidal current vector.

FIG. 6 is a diagram showing another display mode of a tidal current vector.

FIG. 7 is a diagram showing another display form of a tidal current vector.

FIG. 8 is a diagram showing a display screen of a conventional tide display device.

FIG. 9 is a diagram showing another display screen of the conventional tidal current display device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 power flow display section 2 flow rate range display section 3 vector display section 4 azimuth circle 5 line representing horizontal flow direction 6 line representing vertical flow direction 7 fish school display section 9 fish school 10 power flow vector 20a, 20b, 20c transducer 25 Display 31, 32, 33 Display area

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01S 15/96 G01S 15/96 F term (Reference) 2F034 AA04 AC01 AC03 AC11 DA01 DA10 DA16 DB01 DB10 DB15 5J083 AA02 AB01 AB20 AD06 AD12 AD15 AD19 AE04 AF16 BA01 BB01 BE13 BE17 BE45 BE60 DA01 DA05 EA28 EA46 EA50 EB02 EB04 EB13

Claims (6)

[Claims] An ultrasonic wave is emitted from water into and out of water from a transducer and receives an echo signal of the ultrasonic wave to measure the flow velocity and flow direction of a multi-layered tidal current, and displays a tidal current vector representing the measured flow velocity and current direction. In the tidal current display device for displaying on a vessel, the indicator has a display area for each layer arranged in a vertical direction, and individually displays a tidal current vector of a tidal current in each layer in each display area, and displays the tidal current vector at a flow rate. A tidal current display device characterized in that a color is displayed in correspondence with the tidal current. 2. The tidal current display device according to claim 1, wherein a plurality of display areas are provided in the horizontal direction, and the tidal current vectors of the respective layers are displayed continuously with time. 3. The tidal current vector is composed of an azimuth circle, a symbol indicating a horizontal flow direction expressed inside the azimuth circle, and a symbol indicating a vertical flow direction expressed outside the azimuth circle. The power flow display device according to claim 1. 4. The tidal current display device according to claim 1, wherein the display device includes a fish school display section, and the display areas are provided in correspondence with the water depth in the fish school display section. 5. The power flow display device according to claim 1, wherein a power flow vector indicating a horizontal flow direction and a power flow vector indicating a vertical flow direction are selectively displayed. 6. The power flow display device according to claim 1, wherein a power flow vector in a specified range is displayed.