JP2001264437A - System device, and method for measuring distribution of tidal current, and underwater detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently measure a horizontal distribution of tidal current over wide range in a short time. SOLUTION: Flow velocity of the tidal current at a target point TP is measured by each of ships S1-S3, and measured data and position data of the ships are transmitted from other ships S2, S3 to the ship S1 forming a base station. In the ship S1, flow velocity vector V of the tidal current at the target point TP is obtained based on these data and data measured by the ship S1 itself, The horizontal distribution of the tidal current can be obtained by performing this operation at each target point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring system, a measuring device, and a measuring method for measuring a horizontal distribution of a tidal current using a Doppler scanning device, and to moving an underwater target such as a school of fish using a Doppler scanning device. The present invention relates to a system for measuring a horizontal distribution of velocity.

[0002]

2. Description of the Related Art In order to catch fish with a winding net in a fishing boat, it is necessary to accurately grasp the surrounding tide flow and cast the net at an appropriate timing. For this reason, the fishing boat is equipped with a tidal current measuring device for measuring the flow velocity of the tidal current.

FIG. 9 is a view showing the principle of measuring a tidal current using a tidal current measuring device mounted on a ship, where (a) is a sectional view underwater and (b) is a view of the ship viewed from above. . In the figure, S is a ship, A 'is a tidal current measuring device mounted on the ship S, B is an ultrasonic beam emitted underwater from an ultrasonic transducer (not shown) provided on the bottom of the ship S, Z Is the water surface, G is the bottom of the water, and L is the depth of the tidal current to be measured. This example is based on a measurement principle based on a three-beam method, in which an ultrasonic beam B includes three beams B emitted in different directions.
1, B2, and B3, and are fired at intervals of 120 °, for example, as shown in (b). The three-beam method is an example, and the number of the ultrasonic beams B may be three or more.

[0004] Ultrasonic beams B1, B launched into water
2 and B3 are reflected by a body of water at the water depth L, and the ultrasonic echo is received by the ultrasonic transducer. At this time, since the ship S is moving at a predetermined speed with respect to the tidal current, the ultrasonic echo receives a Doppler shift (frequency shift) due to the Doppler effect. Therefore, the Doppler shift amount Δf1 _L obtained from each echo of the transmission beams B1, B2, and B3 from the water depth L in the tidal current measuring device A ′,
By detecting Δf2 _L and Δf3 _L , the ship speed (water speed) of the ship S with respect to the tidal current can be obtained.

On the other hand, the emitted ultrasonic beams B1, B
2 and B3 are reflected on the water bottom G, and the ultrasonic echo is received by the ultrasonic transducer. At this time, since the ship S is moving at a predetermined speed with respect to the water bottom G, the echo undergoes a Doppler shift due to the Doppler effect. Therefore, the transmission beams B1, B2,
By detecting the Doppler shift amounts Δf1 _G , Δf2 _G , and Δf3 _G obtained from the respective echoes from the water bottom G in B3, the speed of the ship S with respect to the water bottom G (ground speed) can be obtained.

By subtracting the water speed from the ground speed obtained as described above, the flow velocity of the tidal current at the water depth L can be calculated, and the result is displayed on the tidal current measuring device A '. Displayed on a container (not shown).

In the fishing method using the winding net, it is necessary to measure the tidal current over a wide area around the ship S. However, in the method using the conventional tidal current measuring device A ',
Although the tidal current just below the ship can be measured, the planar distribution of the surrounding tidal current cannot be measured. For this reason, in order to know how the tidal current is distributed in a plane, it is necessary to perform the measurement operation while the ship S moves finely in the sea area to be measured.

[0008]

However, if the ship repeatedly moves in the sea area to be measured as described above, the measurement of the tidal current is not only time-consuming and inefficient, but also can respond to changes in the tidal current. Could lose the timing of casting. Also, by moving the ship,
The collected fish may be separated and a situation may occur in which the fish cannot be caught even when the net is cast.

SUMMARY OF THE INVENTION The present invention solves the above problems, and provides a tidal current distribution measuring system, a tidal current distribution measuring device, and a measuring method capable of efficiently measuring the horizontal distribution of a tidal current over a wide range in a short time. The task is to provide. It is another object of the present invention to provide an underwater detection system capable of efficiently measuring not only a tide but also a horizontal plane distribution of a target such as a school of fish in a short time.

[0010]

In order to solve the above-mentioned problems, according to the present invention, a flow velocity measuring device provided with a Doppler scanning device, a positioning device for positioning a position of a ship, and data transmission / reception between the ships. The communication device is mounted on two or more ships, and the ships constituting the base station receive data on the flow velocity of the tidal current and the position of the ship from the other ships, and based on these data and the data measured by the own ship. Thus, the horizontal distribution of the tidal current in a certain area is calculated, and this is displayed on a display.

[0011] According to the present invention, by collecting data relating to the flow velocity and the position measured by a plurality of vessels in the vessel of the base station and performing arithmetic processing, it is possible to quickly obtain the plane distribution of the tidal current, It is possible to quickly grasp the tide over a wide area and to cast the net at an early timing.
In addition, since there is no need to repeat the measurement work by circling the ship, the work can be performed efficiently, and the fish can be reliably captured without fear of the fish school being separated.

As the Doppler scanning apparatus used in the present invention, an apparatus described in Japanese Patent No. 2759710 already proposed by the present applicant can be used. According to this, an ultrasonic echo is received by rotating and scanning the receiving beam, and the flow velocity of the tidal current is calculated based on the Doppler shift obtained from the received ultrasonic echo signal.

In the present invention, it is recommended to display the horizontal distribution of the tidal current as a flow velocity vector. In this way, the speed and direction of the tidal current can be understood at a glance, and the tidal current distribution can be grasped intuitively. If the position of each ship is displayed together with the flow velocity vector, the positional relationship between the tidal current and the ship can be instantaneously determined, and the ship can be moved to the optimum place quickly and smoothly.

According to the present invention, the data of the horizontal distribution of the tidal current obtained at the base station is transmitted to another ship or the ground station via the communication device, and the horizontal plane distribution is displayed on the display at the other ship or the ground station. You may make it. According to this, the horizontal distribution of the tidal current can be simultaneously displayed on all ships or ground stations.

In the present invention, a GPS receiver is used as a positioning device, and a plurality of target points forming a grid on a plane are set based on latitude and longitude data obtained from the GPS receiver. It is preferable to calculate and display the flow velocity of the tidal current for each time. With this configuration, the target point can be set with high accuracy by the GPS, and the tidal current distribution can be displayed more accurately.

Further, according to the present invention, the flow velocity measuring device, the positioning device, and the communication device may be provided in a place other than the ship, and the flow velocity of the tidal current at a predetermined place is measured using these devices provided at two or more points. It is possible to configure as a system that does. In this case, the points include both fixed points such as ground stations and buoys at sea provided on land and island, and moving points such as ships. Further, the data measured at each point may be transmitted to a specific point (for example, a ship constituting a base station) among the points to display a tidal current distribution at the specific point. It may be transmitted to another point (for example, a ground station) to display the tidal current distribution at another point.

The present invention is not limited to the tidal current, but also includes a target measuring device for measuring a moving speed of an underwater target using a Doppler scanning device, a positioning device for positioning the position of a ship, and a ship. By installing a communication device for transmitting and receiving data on each of two or more ships, it is possible to configure an underwater detection system for measuring the distribution of the moving speed of a target such as a school of fish. According to this, it is possible to quickly grasp, for example, how fast a school of fish is moving in a certain area, and it is possible to perform an accurate casting.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a diagram showing a tidal current distribution measuring system according to the present invention. In the figure, S1 to S
3 is a ship, A1 to A3 are tidal current measuring devices mounted on each of the ships S1 to S3, and T1 to T3 are each of the ships S1 to S3.
An ultrasonic transducer mounted on the bottom of a ship. Each of the tidal current measuring devices A1 to A3 includes a Doppler scanning device as will be described in detail later. The Doppler scanning device transmits an umbrella-shaped ultrasonic beam Bs from the ultrasonic transducers T1 to T3 as shown in FIG. Is transmitted over a wide area in the water, and the ultrasonic echo Br returning from the water is scanned and received by the ultrasonic transducers T1 to T3. Each tidal current measuring device A1
In A3, the flow velocity of the tidal current is calculated based on the Doppler shift obtained from the received ultrasonic echo signal.

Now, it is assumed that the target point at which the tidal current is to be measured in FIG. 1 is TP, and each of the ships S1 to S3 is traveling at a different point as shown. In each of the vessels S1 to S3, a scanning beam is emitted from the ultrasonic transducers T1 to T3 to a wide area underwater at each position, and an ultrasonic echo returning from the target point TP is received by the ultrasonic transducers T1 to T3. Then, based on the Doppler shift obtained from the received signal, the flow velocity vector of the power flow at the TP is obtained by the power flow measurement devices A1 to A3. When the Doppler scanning device is used, the ultrasonic transducers T1 to T3 of the tide flow at the target point TP are used.
Only the direction component flowing toward is detected. That is, the flow velocity vector v1 is obtained in the tidal current measuring device A1 of the ship S1, the flow velocity vector v2 is obtained in the tidal flow measuring device A2 of the ship S2, and the flow velocity vector v3 is obtained in the tidal flow measuring device A3 of the ship S3. Each of these flow rates is not an absolute flow rate value at the target point TP but a relative flow rate value.

When the flow velocity vectors v1 to v3 are obtained in this way, the perpendicular k1 at the tip of the flow velocity vector v1 is next calculated.
And the intersection X with the perpendicular k2 at the tip of the flow velocity vector v2 is determined. Note that the same result is obtained when the intersection X is obtained as the intersection of the perpendicular k3 at the tip of the flow velocity vector v3 and the perpendicular k1 or the perpendicular k2. Then, if a vector V connecting TP and X is obtained, this vector V becomes a flow velocity vector representing the velocity and direction of the tidal current at the target point TP. The flow velocity represented by the vector V is an absolute flow velocity value at the target point TP. Therefore, if the flow velocity vector V is obtained based on the above principle for a large number of target points forming a predetermined two-dimensional arrangement, the ultrasonic transducers T1 to T1
In the region where the beam from T3 reaches, the horizontal distribution of the tidal current can be known.

In the above case, one of the ships S1 to S3
A ship, for example, a ship S1 functions as a base station, and a ship S2
Velocity vectors v2 and v3 obtained in steps S3 and S3
Data of the ship and the position data of the ship
Sent to The ship S1 obtains the flow velocity vector V at each target point TP based on the data measured by the ship itself and the data sent from the ships S2 and S3, and develops this on the horizontal plane to obtain the horizontal distribution of the tidal current. calculate. The calculated horizontal distribution data is displayed on the display of the tidal current measuring device A1 in a manner described later,
Transmitted to other vessels S2 and S3,
It is displayed on the display of A3.

FIG. 2 is a diagram of an ultrasonic beam that scans underwater over a wide area, and includes an umbrella-shaped ultrasonic beam Bs emitted from the ultrasonic transducers T1 to T3, and the ultrasonic beam Bs.
Shows a beam Br of an ultrasonic echo that is returned by being reflected by an underwater target. The umbrella-shaped ultrasonic beam Bs is simultaneously emitted in all directions from a large number of transducers provided in the circumferential direction of the cylindrical ultrasonic transducer. On the other hand, the beam Br of the ultrasonic echo is received by rotating and scanning the vibrator of the ultrasonic transducer. The turning scan may be performed by electrical scanning or by mechanically rotating the vibrator at high speed.

Here, in order to detect the Doppler shift amount from the ultrasonic echo Br, two ultrasonic receiving beams P and Q having a constant directivity are used. Hereinafter, the principle of detecting the Doppler shift amount using the reception beams P and Q will be described.
This will be described with reference to FIGS.

When the ultrasonic transducer is electrically or mechanically scanned so that the two receiving beams rotate, as shown in FIG. 3, the two ultrasonic receiving beams P and Q always have a predetermined angle. Rotate at a constant speed v around point O (the position of the ultrasonic transducer) while maintaining the relationship separated by θ. Therefore, when receiving an incoming ultrasonic echo signal, the received signal p obtained by each of the ultrasonic received beams P and Q
As shown in FIGS. 4A and 4B, (t) and q (t) are received with a fixed time difference τ. In addition, since each of the ultrasonic receiving beams P and Q is rotating at a predetermined speed v, a Doppler effect occurs on an incoming echo signal.

Now, when attention is paid to the ultrasonic wave receiving beam P which precedes by time τ, assuming that the received signal obtained by the received beam P is p (t), the signal p (t) is expressed by the following equation. Is described. p (t) = S (t) · cos {ωt + α + m (t) + β} (1) where S (t) is an amplitude term determined by the directional characteristics of the receiving beam P and the scanning speed, and cos ｛is In the phase term, ω is the carrier angular frequency of the ultrasonic echo signal arriving from the target, α is the initial phase of the arriving ultrasonic echo signal, β is the phase shift generated in the receiving system, and m (t) is the ultrasonic receiving signal. This is a modulation term due to the Doppler effect caused by receiving an ultrasonic echo signal from a target while turning a wave beam. Therefore,
In the above equation (1), ωt + α represents the phase of the arriving ultrasonic echo signal, and m (t) + β represents the phase change caused by the rotation of the ultrasonic receiving beam P.

Next, assuming that the received signal obtained by the other ultrasonic wave receiving beam Q is q (t), the phase of the arriving ultrasonic echo signal is equal to that of the received signal obtained by the ultrasonic wave receiving beam P. Is the same as ωt + α, but the phase change due to the turning of the ultrasonic wave receiving beam Q is m (t−τ) + β. Therefore, the received signal q (t) is described by the following equation. q (t) = S (t−τ) · cos {ωt + α + m (t−τ) + β} (2)

Here, in order to eliminate the influence of the time difference τ due to the turning of the two ultrasonic receiving beams P and Q, the signal p (t) of the equation (1) is delayed by the time difference τ (FIG. 4 (c)). )
), The received signal pτ (t) is given by pτ (t) = S (t−τ) · cos {ω (t−τ) + α + m (t−τ) + β} = S (t−τ) · cos { ωt + α + m (t−τ) + β−ωτ} (3)

The received signals q (t), p of equations (2) and (3)
Assuming that the phase difference of τ (t) is Δψ, the phase difference Δψ is the carrier angular frequency ω of the ultrasonic echo signal coming from the target.
Is attributed to Here, as is clear from the comparison between the above two equations, Δψ = ωτ, and therefore, ω = Δψ / τ (4). Here, since the time difference τ is known, pτ
If the phase difference Δψ between both signals (t) and q (t) can be detected, the carrier angular frequency ω of the ultrasonic echo signal can be determined based on the equation (4). Then, the Doppler shift amount of the moving target can be detected based on the change in the carrier angular frequency ω, and if the Doppler shift amount is known, the flow velocity of the tidal current can be calculated based on the Doppler shift amount. That is, the Doppler shift amount Δ
f is the transmission frequency of the ultrasonic wave, f ₀ , the sound velocity in the water is c, the flow velocity of the tidal current is v, and the depression angle of the emitted ultrasonic beam is β, Since the values of f ₀ , c, and β are known, if the Doppler shift amount Δf is known, the flow velocity v of the tidal current can be obtained from the above equation. A Doppler scan device using the above-described measurement principle is described in Japanese Patent No. 2759710 filed by the present applicant. In the above example, two ultrasonic receiving beams P and Q are used, but one ultrasonic receiving beam may be swung by setting θ = 360 ° in FIG. Further, three or more ultrasonic receiving beams may be provided.

FIG. 5 is a block diagram showing a specific configuration of the tidal current measuring device A1 mounted on the ship S1 constituting the base station. Reference numeral 1 denotes an arithmetic processing unit that performs data arithmetic and controls the entire apparatus, and includes a CPU. 2 is GPS (Global
Positioning System) The receiver constitutes the positioning device of the present invention. Reference numeral 3 denotes an antenna of the GPS receiver 2. Reference numeral 4 denotes a transceiver for communicating with another ship, which constitutes the communication device of the present invention. Reference numeral 5 denotes an antenna of the transceiver 4. Reference numeral 6 denotes a Doppler scanning device that performs ultrasonic signal processing, 7 denotes an ultrasonic transducer that is driven by the Doppler scanning device 6 to transmit and receive the ultrasonic wave 10 (corresponding to the ultrasonic transducers T1 to T3 in FIG. 1), 8 is RAM, RO
M, a storage unit composed of a hard disk, etc., and 9 is a display unit composed of a liquid crystal display, a CRT, or the like.
The Doppler scanning device 6 and the ultrasonic transducer 7 constitute a flow velocity measuring device 20. Further, the arithmetic processing unit 1, the storage unit 8, and the display 9 are constituted by, for example, a personal computer (hereinafter, referred to as a PC). The tidal current measuring device A1 as described above constitutes a tidal current distribution measuring device of the present invention that receives data measured by the other vessels S2 and S3 and calculates a planar distribution of the tidal current.

FIG. 6 is a block diagram showing a specific configuration of the tidal current measuring devices A2 and A3 mounted on the vessels S2 and S3 other than the base station, and the same parts as those in FIG. is there. 6, the storage unit 8 and the display 9 in FIG. 5 are not provided. Other configurations are the same as those in FIG.

Next, the operation will be described. FIG. 7 is a flowchart showing the procedure of the power flow distribution measuring method according to the present invention. Step S101 is a step of measuring the flow velocity of the tidal current at a predetermined location in each ship by the flow velocity measuring device 20 and measuring the position of the own ship by the positioning device (GPS receiver 2). Step S102 is a step in which the communication device (transmitter / receiver 4) receives data on the flow velocity of the tidal current and the position of the ship from another ship in the ship constituting the base station. Step S103
Is a step of setting a plurality of target points forming a grid on a plane based on the position data. Step S104 is a step of calculating a horizontal distribution of a tidal current in a certain area based on data received from another ship and data measured by the own ship in the ship constituting the base station. Step S105 is a step of determining whether or not the calculation processing of the horizontal plane distribution has been completed for all target points. Step S106
Is a step of displaying the calculated horizontal distribution of the tidal current. Step S107 is a step of outputting or storing the data of the horizontal plane distribution to the outside.

First, the operation of measuring the flow velocity and position data by the tidal current measuring devices A1 to A3 of each ship in step S101 will be described. 5 and 6, the Doppler scanning device 6 transmits the ultrasonic wave
Is supplied with a transmission signal, the ultrasonic beam 10 is transmitted from the ultrasonic transducer 7 into the water. Here, a large number of ultrasonic transducers 7a are arranged on the surface of the cylindrical ultrasonic transducer 7 in the circumferential direction, and the ultrasonic beam 10 is an umbrella-shaped ultrasonic beam Bs shown in FIG. And the ultrasonic vibrator 7
It is fired all at once from a at a predetermined depression angle in all directions.

The ultrasonic beam 10 transmitted into water is reflected by a body of water, and its echo signal (Br in FIG. 2) is received by the ultrasonic transducer 7. At this time, the ultrasonic transducer 7a is electrically or mechanically scanned in the circumferential direction by the Doppler scanning device 6, and the two ultrasonic receiving beams P and Q (FIG. 3) having a fixed angle θ are swirl-scanned. Thereby receiving an echo signal. Based on the time from when the ultrasonic beam 10 is emitted until the echo signal is received,
The tidal current depth can be calculated.

The Doppler scanning device 6, which has received the signals based on the two ultrasonic receiving beams P and Q, detects the amount of Doppler shift from the phase difference between the received signals based on the beams P and Q as described above, and determines the Doppler shift. The flow velocity of the tidal current at a predetermined location (TP in FIG. 1) is calculated based on the amount. The calculated flow velocity data is sent to the arithmetic processing unit 1. The flow velocity data is calculated as an average value of data measured for a fixed time, for example, 15 seconds.

On the other hand, the GPS receiver 2
Position information from a GPS satellite (not shown) is received via the antenna 3, the current position of the ship is calculated based on the position information, and the data (latitude and longitude) is sent to the arithmetic processing device 1 together with time information. In the tidal current measuring devices A2 and A3 in FIG. 6, the data of the flow velocity and the ship position received by the arithmetic processing unit 1 are transmitted from the transmitter / receiver 4 via the antenna 5,
The signal is transmitted to the power flow measuring device A1 of the base station in FIG. 5 at a predetermined timing.

The power flow measuring device A1 of the base station obtains the horizontal distribution of the power flow according to the procedures of steps S102 to S107. Hereinafter, the operation of the power flow measuring device A1 will be described. In the tidal current measuring device A1, data transmitted from the tidal current measuring devices A2 and A3 of the other vessels S2 and S3 is received by the transceiver 4 via the antenna 5 (step S10).
2). The received data is stored in the storage unit 8. The data of the flow velocity and the position of the ship measured by the own ship by the above-described method are also stored in the storage unit 8.

Subsequently, a target point TP for measuring the power flow is set (step S103). The target point TP is represented by latitude and longitude obtained from the position information of the GPS receiver 2, and is set so as to form a grid on a plane as shown in FIG.
This setting can be freely performed by the user. Specifically, in the PC including the arithmetic processing unit 1 and the storage unit 8, input means (not shown) such as a keyboard and a mouse is used. To set.

Next, the arithmetic processing unit 1 compares the data on the flow velocity of the tidal current measured on the own ship and the position of the ship with the other ship S
2, the data on the flow velocity of the tidal current and the position of the ship received from S3 are read out from the storage unit 8, and based on these,
The flow velocity vector V is calculated for the set target point TP according to the principle described with reference to FIG. 1 (step S104). And all target points T
Steps S103 to S104 are repeated until the calculation of the flow velocity vector V for P is completed (step S105). In the above description, the case where the number of vessels is three is taken as an example. However, when the number of vessels is four or more, for example, the vessels S1, S2, S
3 and the data obtained from the vessels S1, S2, S4. When a plurality of measurement data are obtained in this way, their standard deviations are obtained and used as an error index. . The standard deviation can be calculated by the following equation. Here, SD is the standard deviation, Xi is the value of each measurement data, n
Is the number of data.

The flow velocity vector calculated for each target point TP is displayed on the display 9 in a manner as shown in FIG. 8 (step S106), and the data is externally output and stored and stored in the storage unit 8. Is performed (step S107).

In FIG. 8, the horizontal axis represents longitude and the vertical axis represents latitude, and one square indicates one target point TP. Then, a flow velocity vector 30 is displayed for each target point. The direction of the flow velocity vector 30 indicates the direction of the tidal current, and the length of the vector indicates the flow velocity of the tidal current. L1, L2, and L3 circled indicate the positions of the vessels. If the position of the ship is displayed together with the flow velocity vector 30 in this manner, the positional relationship between the tidal current and the ship can be immediately known, so that it is possible to quickly move to the optimum casting location. Note that the screen in FIG. 8 is updated at regular intervals. This fixed time can be arbitrarily set by the user on the PC, for example, in the range of 15 seconds to 1 hour. Also, the resolution (grating width) of the target point TP can be arbitrarily set by the PC.

In FIG. 8, the length of the vector 30 represents the flow velocity of the tidal current. Alternatively, or in addition, the vector 30 is displayed in a different color according to the flow velocity. May be expressed. Further, the error index (standard deviation) is compared with a predetermined threshold value, and when the error index value exceeds the threshold value, the flow velocity vector 30 is displayed in a specific color so that data having low reliability can be identified. You may.

As described above, according to the present embodiment, the distribution of the tidal current in a certain area is displayed in the form of the vector 30 on the display 9 of the ship of the base station. Distribution can be grasped at a glance. Since the base station vessel receives the data measured by the other vessels and calculates the tidal current distribution by performing arithmetic processing together with the measurement data of the own vessel, it is necessary to perform the measurement work by patroling the vessel. And a wide range of tidal current distribution can be quickly grasped. As a result, the net can be cast at an appropriate timing, and the fish school does not escape. In addition, GPS receiver 2
Since the flow velocity vector for each target point is obtained based on the position information, the accurate tidal current distribution can be known.

On the screen shown in FIG. 8, the distribution of the flow velocity vector 30 at an arbitrary water depth can be displayed according to the setting of the user. In order to measure the flow velocity at an arbitrary water depth, the angle of the ultrasonic wave 10 transmitted from the ultrasonic transducer 7 may be variably controlled by the Doppler scanning device 6. Further, a mode for reproducing the data stored in the storage unit 8 may be provided so that the tidal current distribution data for a certain period in the past is displayed on the display 9.

In the above embodiment, the horizontal distribution of the tidal current is displayed only on the indicator 9 of the ship at the base station. However, the data calculated at the ship at the base station is sent to other ships, and the data is calculated at all ships. A horizontal plane distribution may be displayed. In this case, the configuration of FIG. 5 similar to that of the base station may be adopted as the tidal current measuring device of another ship. In FIG. 5, data to be sent to another ship is transmitted from the transceiver 4. However, if there is another communication device other than the transceiver 4, the data may be transmitted from the communication device. Alternatively, data may be sent to the ground station in place of or in addition to another ship, and the ground plane distribution may be displayed at the ground station. In this case, the ground station only needs to have at least a receiver and a display.

In the above embodiment, the tidal current measuring devices A1, A2 and A3 are all mounted on a ship to measure the tidal current. However, even if the tidal current measuring device A1 of the base station is installed on a land island, for example. Good. In this case, the transmitter / receiver 7 in FIG. 5 may be connected to the Doppler scan device 6 with a long cable, and only the transmitter / receiver 7 may be provided underwater. Further, data may be transmitted from the base station to the ship so that the horizontal plane distribution is displayed on the ship. Alternatively, the tidal current measuring device A1 of the base station is mounted on a ship, and the tidal current measuring devices A2 and A3 are mounted.
May be installed on a structure such as a buoy deployed on the sea to measure the tidal current. In this case, it is only necessary to display the horizontal plane distribution at the base station. Further, in the above embodiment, one base station is used, but a plurality of base stations may be provided.

Furthermore, the data measured at each point may be collected at a point different from the point where the flow velocity or the position is measured, and the tidal current distribution may be displayed. For example, in FIG. 1, each vessel S1 to S3 is equipped with a velocity measuring device equipped with the above-described Doppler scanning device, a positioning device including a GPS receiver and a transmitting device, and data measured by the velocity measuring device and the positioning device is stored. The signal is transmitted from the transmitting device to another ground station. The ground station receives the transmission data from each of the ships S1 to S3, calculates the horizontal distribution of the tidal current according to the principle described above, and displays this on the display in a manner as shown in FIG. Therefore, the ground station only needs to include a receiver for receiving data transmitted from each point and a display for displaying a tidal current distribution based on the received data. Is not always necessary. In the above example, the ground station is taken as an example of another point.
A ship other than 3 may be used.

Further, in the above embodiment, the measurement of the tidal current has been described as an example. However, the present invention may be configured as an underwater detecting device that measures the horizontal distribution of the moving speed of a target in water such as a school of fish other than the tidal current. Can be. In this case, the flow velocity measuring device 20 shown in FIGS. 5 and 6 may be replaced with a target measuring device adapted to the target to be measured. For example, when detecting a school of fish, the target measuring device may be configured by a known fish finder equipped with an ultrasonic transducer and a Doppler scan device. Other configurations are the same as those in FIGS. 5 and 6, and the measurement principle is the same as that in FIG. According to this, it is possible to quickly grasp the horizontal distribution of the moving speed of the fish school or the like in the predetermined area, and to perform an accurate casting.

The present invention can adopt various forms other than the above-described embodiment. For example, in the above embodiment, the case where the number of ships is three or more is described as an example,
As described with reference to FIG. 1, the flow velocity vector V includes v1 and v2.
, Or v1 and v3 or v2 and v3, so that measurement can be performed by two ships in principle. However, in the case of two vessels, the flow velocity vector V cannot be determined because the perpendiculars k1 to k3 in FIG. 1 do not intersect even if the flow velocity of the target point on the straight line connecting the two is determined. Therefore, it is preferable to use three or more ships so that the flow velocity at such a target point can also be obtained.

Further, in the above embodiment, the data of the flow velocity measured in each ship is transmitted to the base station at a predetermined timing together with the data such as the current position of the ship and the speed of the ship. Synchronization between them is performed, but the method of achieving synchronization is not limited to this. For example, a synchronization signal may be supplied from the GPS receiver 2 to the Doppler scan device 6 at predetermined time intervals, and the data may be transmitted to the base station based on the synchronization signal. Alternatively, instead of these, a synchronization signal is transmitted from the transceiver 4 of the ship constituting the base station to another ship,
In other ships, the above data may be transmitted to the base station based on the synchronization signal received by the transceiver 4.

[0050]

According to the present invention, the plane distribution of the tidal current can be quickly obtained without patrol of the ship.
The measurement work can be performed efficiently, and the distribution of the tidal current can be quickly grasped and an accurate net can be cast. In addition, it is possible to effectively prevent fish schools from being separated due to patrol of ships.

[Brief description of the drawings]

FIG. 1 is a diagram showing a tidal current distribution measuring system according to the present invention.

FIG. 2 is a diagram of an ultrasonic beam that scans a wide area in water.

FIG. 3 is a diagram for explaining swiveling scanning of an ultrasonic wave receiving beam.

FIG. 4 is a waveform diagram of a reception signal obtained by an ultrasonic wave reception beam.

FIG. 5 is a block diagram of a tidal current measuring device in a ship of a base station.

FIG. 6 is a block diagram of a tidal current measuring device in a ship other than the base station.

FIG. 7 is a flowchart showing a procedure of a power flow distribution measuring method according to the present invention.

FIG. 8 is a display example of a horizontal distribution of a tidal current.

FIG. 9 is a diagram showing a conventional principle of measuring a tidal current.

[Explanation of symbols]

 S1 to S3 Ship A1 to A3 Tidal current measuring device T1 to T3 Ultrasonic transducer Bs Ultrasonic beam Br Ultrasonic echo beam V Flow velocity vector P, Q Ultrasonic receiving beam TP Target point 1 Processing unit 2 GPS receiver (Positioning device) 4 Transceiver (communication device) 6 Doppler scan device 7 Ultrasonic transducer 8 Storage unit 9 Display 10 Ultrasonic beam 20 Flow velocity measuring device 30 Flow velocity vector

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J062 BB07 CC07 HH04 5J083 AA02 AB01 AB20 AC29 AD06 AD11 AD12 AE04 AE06 AF15 AG09 BA01 BC11 BD08 BD11 BD12 CA12 DA01 EA26 EA31

Claims (11)

[Claims] 1. A flow velocity measuring device for measuring a flow velocity of a tidal current, a positioning device for measuring a position of a ship provided with the measuring device, and a communication device for transmitting and receiving data between the ships. Respectively mounted on two or more ships, the flow velocity measuring device, an ultrasonic transducer, and emits an ultrasonic beam from the ultrasonic transducer to a wide area of the water, and the ultrasonic echo returning from the water. A Doppler scan device that receives the ultrasonic transducer and calculates the flow velocity of the tidal current based on the Doppler shift obtained from the ultrasonic echo is provided. The position of the ship is measured by the positioning device of each ship, and at least one of the two or more ships constitutes a base station, and the flow velocity and the flow rate of the tide measured on the other ship are measured. The communication device receives data relating to the position of the tidal current and the position of the ship, and the ship constituting the base station, based on the data received from the other ship and the data measured by the own ship, based on the horizontal distribution of the tidal current in a certain area. A tidal current distribution measurement system which calculates and displays the horizontal plane distribution on a display. 2. The tidal current distribution measuring system according to claim 1, wherein said ultrasonic wave transmitter and receiver emits an ultrasonic beam to a wide area underwater, and receives an ultrasonic echo by rotating and scanning the received beam. 3. The tidal current distribution measuring system according to claim 1, wherein a horizontal distribution of the tidal current is displayed as a flow velocity vector on the display. 4. The tidal current distribution measuring system according to claim 3, wherein the position of each ship is displayed together with the flow velocity vector. 5. The data of the horizontal distribution of the tidal current calculated by the ship constituting the base station is transmitted from the communication device of the base station to another ship or the ground station, and the other ship or the ground station transmits the data by the communication device. The tidal current distribution measuring system according to any one of claims 1 to 4, which receives and displays a horizontal distribution of the tidal current on a display based on the received data. 6. An ultrasonic wave transmitter / receiver mounted on a ship constituting a base station for measuring a tidal current distribution, and the ultrasonic wave transmitter / receiver transmits an ultrasonic beam to a wide area in water. A flow velocity measuring device including a Doppler scan device that receives an ultrasonic echo returning from underwater in the ultrasonic transducer and calculates a flow velocity of a tidal current based on a Doppler shift obtained from the ultrasonic echo. A positioning device for positioning the position of the ship, a communication device for receiving data on the flow velocity of the tidal current measured in the other ship and the position of the ship from the other ship, and the communication device receiving from the other ship Data on the flow velocity of the tidal current and the position of the ship, and data on the flow velocity of the tidal current and the position of the ship measured by the flow velocity measuring device and the positioning device in the own ship. A tidal current distribution measuring device comprising: an arithmetic processing device for calculating a horizontal distribution of a tidal current in a certain area based on the information; and a display for displaying the horizontal distribution of the tidal current calculated by the arithmetic processing device. 7. The tidal current distribution measuring device according to claim 6, wherein the data of the horizontal distribution of the tidal current calculated by the arithmetic processing unit is transmitted to another ship or a ground station via a communication device. 8. A flow velocity measuring device for measuring a flow velocity of a tidal current, a positioning device for measuring a position of a point provided with the measuring device, and a data measuring device for measuring the flow velocity. A transmitting device for performing transmission is installed at each of two or more points, and the flow velocity measuring device emits an ultrasonic beam from the ultrasonic transducer and the ultrasonic transducer to a wide area in the water, A Doppler scan device that receives an ultrasonic echo returning from underwater by the ultrasonic transducer and calculates a flow velocity of a tidal current based on a Doppler shift obtained from the ultrasonic echo, and a flow velocity measuring device at each point. Measure the tidal flow velocity at a given location, and measure the position of the point with a positioning device at each point. Location data at a specific point or at a different point from each point, and at the specific point or another point, the horizontal distribution of the tidal current in a certain area based on the received data. , And the horizontal distribution is displayed on a display device. 9. A flow velocity measuring device having a Doppler scan device for measuring a flow velocity of a tidal current, a positioning device for measuring a position of a ship, and a communication device for transmitting and receiving data between the ships. On each of two or more ships,
A method for measuring a horizontal distribution of a tidal current in a fixed area, wherein in each vessel, the flow velocity measuring device measures a flow velocity of a tidal current at a predetermined location, and the positioning device measures a position of the own ship; In the ship constituting the base station among the above ships, receiving the data on the flow velocity of the tidal current and the position of the ship from another ship by the communication device, and in the ship constituting the base station, from the other ship A step of calculating a horizontal distribution of the tidal current in a certain area based on the received data and the data measured by the own ship; and a step of displaying the horizontal distribution of the calculated tidal current. Measuring method. 10. A GPS receiver is used as a positioning device, a plurality of target points are set based on latitude and longitude data obtained from the GPS receiver, and a flow velocity of a tidal current is calculated and displayed for each target point. The tidal current distribution measuring method according to claim 9. 11. A target measuring device for measuring a moving speed of a target in water, a positioning device for measuring a position of a ship provided with the target measuring device, and transmission and reception of data between the ships. A communication device for performing the above is mounted on each of two or more ships, and the target measuring device is configured to emit an ultrasonic beam from the ultrasonic transducer and an ultrasonic beam from the ultrasonic transducer to a wide area in the water, A Doppler scanning device that receives an ultrasonic echo returning from underwater by the ultrasonic transducer and calculates a flow velocity of a tidal current based on a Doppler shift obtained from the ultrasonic echo; The speed of the target at a predetermined place is measured by the device, and the position of the ship is measured by the positioning device of each ship. At least one of the two or more ships constitutes a base station, and the position of the ship is measured by another ship. Marked The communication device receives data on the dynamic speed and the position of the ship, the ship constituting the base station, based on the data received from the other ship and the data measured by the ship itself, the target in a certain area Calculate the horizontal distribution of the moving speed,
An underwater detection system, wherein the horizontal plane distribution is displayed on a display.