JP4020300B2 - Fish detection information wireless transmission display system, wireless transmission device and reception display terminal - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fish detection information wireless transmission display system for providing fish detection information to a fisherman or the like in a vessel such as a recreational fishing boat, and a wireless transmission device and reception display terminal therefor.
[0002]
[Prior art]
On a ship such as a recreational fishing boat, a fish finder is usually installed on the ship. In order to provide fishermen with fish detection information obtained by the fish detector, such as water depth, fish quantity, fish depth, water temperature, current position, etc., the boatman announces or the fisherman They enter the wheelhouse and check fish hunting images. However, there are dissatisfactions such as missing announcements and not being able to concentrate on fishing.
[0003]
2. Description of the Related Art Conventionally, an apparatus for transmitting an image of a fish finder to another place and restoring the image has been put into practical use as a wireless transmission type fish finder for use in a purse seine or two trawlers. This is used for the purpose of seeing the image of the fish finder installed on the stationary net on land, or viewing the image of the fish finder of the slave vessel on the ship.
[0004]
As shown in FIG. 7, the configuration of this conventional wireless transmission type fish finder is, for example, on the side of the slave ship (FIG. 7A), the fish detection wave signal and the transmission synchronization before the display image is displayed from the fish finder 71. The signal is branched from the middle, input to the transmitter 72, modulated by voltage-frequency conversion (V / F conversion) or the like, and transmitted from the wireless transmission unit 74 as wireless transmission data. Each of the wireless transmission data has, for example, a frequency of 40 MHz, an output of 100 mW, and an effective work range (radio wave reach) of about 10 km. For example, on the ship side ((b) in the figure), the radio transmission data is received by the radio receiver 76 at the receiver 75, and is subjected to frequency-voltage conversion (F / V conversion) by the demodulator 77, and in the signal. The included transmission signal is separated by the data processing unit 78 and the fish detection wave signal is output to the ship side fish finder 79 together with the transmission synchronization signal. In the main line side fish finder 79, the transmitted fish detection signal is input to a circuit portion in which the fish detection signal is to be generated, and a fish search image is displayed. The crew on the side of the ship grasps the situation on the side of the ship by using this fish search video.
[0005]
[Problems to be solved by the invention]
In this conventional wireless transmission type fish finder, only the fish detection wave signal (detection waveform) is sent, so even if a GPS receiver or a water temperature sensor is installed in the fish finder on the transmitting side, Location data and water temperature data cannot be used. Further, since the fish detection wave signal of the fish detector on the transmission side is taken out, it is difficult to connect to the transmitter, and it is difficult to connect the fish detectors of different manufacturers due to the necessity of signal adjustment. In addition, the fish detector and the fish detector are connected to each other, and the radio wave to be used is as strong as 100 mW or 10 km, which makes the apparatus large and expensive.
[0006]
Therefore, this conventional wireless transmission type fish finder can provide fishermen with information on the fish finder of the fish finder such as water depth, amount of fish, fish depth, water temperature, current position, etc. on a vessel such as a recreational fishing boat. It was practically impossible to use it.
[0007]
Therefore, in view of the problems as described above, the present invention can provide various fish finder information to a fisherman on a ship such as a fishing boat in real time, in a small size and at a low cost for each individual. An object of the present invention is to provide a fish detection information wireless transmission display system, a wireless transmission device therefor, and a reception display terminal.
[0008]
[Means for Solving the Problems]
The fish detection information wireless transmission display system according to claim 1 is a fish detection information wireless transmission display system used inside a ship,
It is NMEA data that consists of NMEA standard data and optional data including information on fish depth and fish quantity, and is based on NMEA standards, and each piece of information is expressed numerically. A fish finder that outputs serially every predetermined time;
A fish detection information group from the fish detection device is input, and only information necessary as display fish detection information including water depth information, fish depth information, and fish quantity information is extracted from the fish detection information group, and information that is not displayed is extracted. A wireless transmission device having data editing means to be deleted, and wireless transmission means for modulating the display fish finder detection information extracted by the data editing means and transmitting the information to the inside of the ship by specific low-power radio;
Radio receiving means for receiving radio waves transmitted by the specific low-power radio from the radio transmitting apparatus inside the ship, and demodulating a fish detection information group for display in which each information is represented by a numerical value, and demodulated Based on the display fish detection information group including the water depth information, fish depth information and fish quantity information, the seafloor line is displayed on the screen using the history of the water depth information, and the water depth, fish depth, fish school on the screen. One or more reception display terminals having display means for displaying the fish detection information including the quantity by numbers or symbols ;
It is characterized by providing.
[0010]
The fish detection information wireless transmission display system according to claim 2 is the fish detection information wireless transmission display system according to claim 1 , wherein the data editing means further obtains a water depth value obtained at predetermined time intervals for the extracted water depth information. The smoothing process by interpolation is performed according to the above.
[0011]
The wireless transmission device according to claim 3 is NMEA data conforming to the NMEA standard, comprising NMEA standard data and optional data including information on fish depth and fish quantity, each of which is represented by a numerical value. Only the information necessary for display fish detection information including water depth information, fish depth information, and fish quantity information is extracted from the fish detection information group that is serially input as digital data every predetermined time, and information that is not displayed is deleted. Data editing means, and wireless transmission means for modulating the display fish finder detection information extracted by the data editing means and transmitting the information by specific low power radio.
[0013]
According to a fourth aspect of the present invention, in the wireless transmission device according to the third aspect , the data editing unit further performs a smoothing process by interpolation on the extracted water depth information according to a water depth value obtained every predetermined time. It is characterized by that.
[0014]
The reception display terminal according to claim 5 is composed of NMEA standard data and optional data including information on fish depth and fish quantity, and is extracted as information necessary for display from NMEA data conforming to the NMEA standard, and every predetermined time. depth information arranged serially in a radio receiving unit that receives and demodulates the radio wave that is modulated by the display fish finder information including fish depth information and fish school amount information, water depth information is demodulated, a fish depth information and fish school based on the plurality of display fish detector information including the amount information, and displays the submarine line on the screen using the history of the water depth information, water depth on the screen, a fish depth displaying fish detector information including fish weight It is characterized by having a display means for displaying in numerical or symbol .
[0015]
The reception display terminal according to claim 6 is the reception display terminal according to claim 5 , for outputting the fish detection information for display including the demodulated water depth information, fish depth information, and fish quantity information to the outside. An output terminal is provided.
[0016]
According to the present invention, an occupant such as a fishing boat's fisherman can detect the fish detection information such as the position of the fishing ground, water depth (including its history), fish depth, fish quantity, water temperature in real time. It becomes possible to know.
[0017]
In addition, the video is received and displayed on the display terminal, a display form simulating a normal fish hunting video, that is, a screen that is scrolled sequentially, and each information at that time is displayed on the screen as numerical values and / or symbols. High visibility can be obtained.
[0018]
Further, it is possible to use the fish detection information by simply connecting all the fish detectors equipped with the NMEA connector without any modification.
[0019]
Moreover, only the data to be displayed on the fisherman's reception display terminal is obtained from the fish detection information group, typically NMEA data, which is serially output as digital data every predetermined time and the information is represented by numerical values. Since data is extracted and transmitted after data editing, data processing at a receiving display terminal that is required to be simple, small, and inexpensive can be reduced. Therefore, the reception display terminal possessed by each angler can be made small and inexpensive. Furthermore, an external output terminal is provided on the reception display terminal, and a plurality of information including water depth information, fish depth information, and fish quantity information can be output to the outside. It becomes possible to use.
[0020]
In addition, when the output interval of NMEA data is long (for example, 2 seconds interval, 4 seconds interval), the data editing unit extracts the data necessary and interpolates the water depth data to smooth the water depth before transmission. To do. Therefore, a smooth fish search image can be displayed without increasing the data processing burden associated with the interpolation processing at the reception display terminal.
[0021]
In addition, transmission of fish detection information from the wireless transmission device is performed by specific low power wireless. Since the fish detection information only needs to be transmitted to a fisherman or the like in the same fishing boat, the distance for this is at most about 20 to 30 m, and there is no problem in transmission by the specific low power radio. And by transmitting by specific low-power radio, it is possible to transmit the fish detection information to all fishers who need the fish detection information wirelessly arbitrarily and easily without being restricted by the Radio Law as in the conventional example. Can do.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
1 is a diagram showing a system configuration of a fish detection information wireless transmission display system of the present invention, FIG. 2 is a diagram showing a configuration of the wireless transmitter, and FIG. 3 is a diagram showing a configuration of the reception display terminal. is there. FIG. 4 is a diagram showing the configuration of the display unit in the reception display terminal.
[0024]
In FIG. 1, this system is equipped on a vessel such as a recreational fishing boat (hereinafter referred to as a recreational fishing vessel), and a fish finder 10 provided in a steering chamber and the like, and this fish finder. A radio transmitter 20 that receives fish detection information from 10 and wirelessly transmits it, and a crew member such as a fisherman (hereinafter referred to as a fisherman) in a recreational fishing boat, for example, carries the received data and displays received data. It consists of display terminals 30 and 30A. The reception display terminal may be carried by each angler, or may be provided at various locations on the ship. Therefore, the number of reception display terminals may be any number, and the number is not limited.
[0025]
The fish finder 11 includes a transmitter / receiver, a signal transmission / reception device, a display device, and the like necessary for normal ultrasonic fish finder detection. The fish finder 11 is coupled to the GPS antenna 13 and the water temperature sensor 12 to obtain position and other GPS information. A GPS receiver for acquisition, a water temperature detection device for measuring the water temperature, and the like are included to constitute the fish finder 10.
[0026]
The fish finder is provided with an NMEA connector for outputting NMEA data. By connecting the NMEA connector and the wireless transmitter 20, the NMEA data is supplied to the wireless transmitter 20.
[0027]
The NMEA standard is a standard established by the National Marine Electronics Association in the United States to transmit data between electronic devices mounted on ships. Defines data transmission protocol, timing, etc.
[0028]
NMEA data in accordance with this NMEA standard is now widely used in marine electronic equipment, including fish finders, and the interconnection and data communication between marine electronic equipment that handles information digitally. Is used. Since this standard is determined to support unidirectional transmission of serial data from a sender (talker) to a plurality of receivers (listeners), the fish detection information is converted into a plurality of pieces of information as in the present invention. It is particularly suitable for application to a system in which a fisherman is transmitted and displayed wirelessly.
[0029]
The NMEA data output from the fish finder 10 includes, as standard specifications, data necessary for fish finder information such as GPS information, water depth, and water temperature, and is not necessarily required for displaying fish finder images, such as the bow direction, wind direction, The wind speed, own ship data, and various other data are included as digital numerical data. In addition, for example, GPS information includes information necessary for display such as position information such as latitude and longitude, speed information, and time information, and data unnecessary for displaying fish hunting images such as GPS almanac data, GPS ephemeris data, and standard time. Are mixed.
[0030]
In addition, although the information of the fish depth and the fish quantity to be displayed as the fish detection information is not stipulated as a standard of the NMEA data, a specific code for that is given by the application. In the fish finder 11, the fish depth and the amount of fish are converted into numerical data by a normal echo signal reception process, and the information on the fish depth and the amount of fish is included in the NMEA data as option data using a given specific code. .
[0031]
As described above, the NMEA data output from the fish finder 10 includes a lot of data unnecessary for the display in addition to the data necessary to be displayed as the fish finder information. Since it is not possible to modify these data so that the fish finder 10 selectively outputs for display in consideration of the use for other purposes, all the output NMEA data is input to the wireless transmitter 20. Will be.
[0032]
Referring to FIG. 2, the wireless transmitter 20 first extracts only data necessary for displaying as fish detection information from the NMEA data input by the data editing unit 21. The data necessary for this display includes GPS information (of which latitude / longitude position information, date / time information, ship speed information is required), water depth information (water depth value corrected for flooding), water temperature information, fish depth Information (fish depth corrected for flooding) and fish quantity information are required. These pieces of information are merely examples, and information not to be displayed may be deleted from these pieces of information, or may be further added if there is information to be displayed additionally. The data format of the extracted fish detection information is converted into a data format suitable for transmission and output.
[0033]
The NMEA data output from the fish finder 10 is output at predetermined time intervals. This output interval depends on the type of fish finder, but for example, the latest ones often have one second intervals, but there are also two second intervals and four second intervals. When displaying on the reception display terminal 30, in order to improve the display quality, it is necessary to interpolate, for example, water depth data for smooth display, particularly for those with long output intervals. In this case, the interpolation processing requires a CPU capable of high-speed processing, and the data editing unit 21 reduces the number of processing at the reception display terminal that is battery-powered and requires a reduction in size and price as much as possible. Interpolation processing (smoothing processing) is performed.
[0034]
When interpolation processing is performed, the data up to the previous time and the current data are referred to, and interpolation data between them is obtained. For this reason, data to be subjected to interpolation processing (for example, water depth data) is displayed with a delay of the output interval of the NMEA data, but the boat speed when fishing is usually slow (for example, tide This is not a problem on the actual display. It should be noted that the extent to which this interpolation process is performed for which NMEA data has an output interval is appropriately determined in consideration of the ship speed, the seabed state, and the display quality. In addition, since the system of this invention can be used also in a lake, a river, etc., the seabed shall be read as a waterbed in that case.
[0035]
The modulation unit 22 receives the fish detection information that has been subjected to data extraction and smoothing processing by the data editing unit 21, is subjected to, for example, FSK (frequency shift keying) modulation, and is transmitted from the wireless transmission unit 23 as specific serial power as digital serial data. It is transmitted wirelessly. Since the transmitted data only needs to be transmitted effectively in the recreational fishing boat, the data that can reach the range of 20 to 30 m is usually sufficient.
[0036]
For specific low-power radio, the usage, radio wave format, frequency, antenna power, etc. are stipulated in the Radio Law Enforcement Regulations (Article 6, Paragraph 2, Item 2). Similarly, it can be used without requiring a radio station license. The mode of use in the present invention corresponds to a telemeter that automatically displays and records the measurement results of a remote measuring instrument using radio waves.
[0037]
In this case, the one specified requirement is that the frequency is 429.175 MHz or more and 4297375 MHz or less plus an integral multiple of 12.5 kHz (that is, the frequency of 400 MHz band), the antenna power is 0.01 W or less, It is a one-way communication method, and can be used for radio transmission on a fishing boat under these conditions. Therefore, in the present invention, the specific low power radio is used.
[0038]
In the present invention, since it is only necessary to be able to perform short-distance wireless communication of about 30 m, Bluetooth (Bluetooth), which is a short-distance wireless communication method using a frequency of 2.4 GHz band, can be used. For this reason, the specific low-power radio of the present invention includes Bluetooth (registered trademark) in addition to those prescribed in the enforcement regulations of the Radio Law.
[0039]
3 and 4, in the reception display terminal 30, the fish detection information wirelessly transmitted from the wireless transmitter 20 is received by the wireless reception unit 31, FSK demodulated by the demodulation unit 32, and the data output unit The image is supplied to the display unit 40 via 33. The display unit 40 displays a simulated fish finder display image based on the transmitted fish finder information.
[0040]
In addition to supplying the fish detection information to the display unit 40, the data output unit 33 outputs the fish detection information from an output terminal provided in the reception display terminal 30 for external use. The output format for external use may be the same data format as that supplied to the display unit 40, or may be a data format reconverted to the NMEA data format. The reception display terminal 30A and other reception display terminals are configured similarly.
[0041]
The display unit 40 includes an input interface 41 that receives input data including GPS information (position information of latitude / longitude, date / time information), ship speed information, water depth information, water temperature information, fish depth information, and fish amount information. The CPU 42 that controls the display, the display memory, the working memory, the RAM 43 that is used as other memory, the display control unit composed of the LCD driver 44, the LCD display unit 45, and others are not shown. A ROM or the like that stores a control program is included. Since the display unit 40 is a main part of the reception display terminal, it is desirable that the display unit 40 be particularly small, light, and inexpensive, and not only the LCD but also other portable displays such as LEDs can be used. .
[0042]
Next, the operation of the present invention will be briefly described with reference to FIG. 5 showing the display screen of the reception display terminal.
[0043]
NMEA data is supplied from the fish finder 10 to the wireless transmitter 20 as digital data in a serial form at regular intervals (for example, every second). In the wireless transmitter 20, only the fish detection information necessary for display by the data editing unit 21 is extracted, the water depth data is smoothed as necessary, and modulated by the modulation unit 22. To the reception display terminal 30 in the fishing boat by specific low power radio.
[0044]
In each reception display terminal 30 or the like, the signal is received by the wireless reception unit 31, demodulated by the demodulation unit 32 to obtain fish detection information, and supplied to the display unit 40 via the data output unit 33.
[0045]
As shown in FIG. 5, the LCD display unit 40 displays the seabed line B indicating the depth of the seabed (water depth) and the history of the fish depth / fish quantity from past to present on the screen. Scroll from right to left. The speed of this scrolling depends on the set water depth range R of the fish finder 11.
[0046]
The submarine line B is displayed on the screen so as to have a predetermined width, but the uppermost side of the submarine line B represents the water depth at that time, and the width is shown in the image of a normal fish finder. It is simulated so as to be displayed in a similar manner, and is set to a predetermined width according to the water depth range R.
[0047]
In addition, the fish school amount and the fish school depth are represented by a fish symbol F, and the position of the fish symbol F in the depth direction and the size of the symbol are changed according to the fish school depth and the fish school amount. The size of the fish school amount is divided into, for example, a plurality of stages (3 to 5 stages), and the size of the fish symbol F is increased stepwise according to the stages. Further, the fish school depth is displayed as a numerical value (for example, 50 m) in the fish symbol.
[0048]
On the screen, the latest fish detection information at that time, in this example, the latitude / longitude of the ship's position, date / time, ship speed (eg, 1.2 KTS), water temperature (eg, 15.2 ° C.) ) Is displayed, and the depth of the seabed, which is the most necessary information for the fisherman, is displayed as a number (for example, 64 m) separately from the display of the seabed line B.
[0049]
Thus, the display control for displaying on the LCD display unit 45 is performed by the CPU 42, the RAM 43, the LCD driver 44, and the like based on the fish detection information input as numerical data.
[0050]
6A and 6B exemplarily show the effect of the smoothing process on the water depth data performed by the data editing unit 21 of the wireless transmitter 20 on the screen of the display unit 45 together with the water depth data. It is.
[0051]
FIG. 6A shows an example in which smoothing processing is not performed when the input NMEA data is at intervals of 4 seconds. In this example, since the boat speed is 1.2 KTS, the fishing boat will travel about 2.5 m in 4 seconds. Since the same water depth is displayed for 4 seconds and 2.5 m, the seabed line is displayed as jagged as shown in the figure. The actual depth change cannot be displayed.
[0052]
On the other hand, in FIG. 5B, smooth water depth data is created by interpolating the water depth data in the NMEA data input at intervals of 4 seconds with a plurality of data under the same conditions, and received and displayed as fish detection information. Since it is transmitted to the terminal, as shown in the figure, it is possible to display a depth change that is almost the same as a normal fish finder image.
[0053]
In this example, two interpolation data are inserted between the water depth data, but an arbitrary number of interpolation data can be inserted.
[0054]
In the present invention, an appropriate fish finder image can be provided to the reception display terminal by performing interpolation processing of the water depth data and extracting necessary fish finder information from the NMEA data. For this reason, the necessary data processing is performed on the wireless transmitter side, and the processing on the reception display terminal side is kept to the minimum necessary. Therefore, the reception display terminal can be configured in a small size, weighing, and inexpensive, Particularly suitable for use.
[0055]
【The invention's effect】
According to the present invention, a passenger such as a fishing boat's fisherman can detect fish detection information such as the location of the fishing ground, water depth (including its history), fish depth, fish quantity, and water temperature in real time. It becomes possible to know.
[0056]
In addition, the video is received and displayed on the display terminal, a display form simulating a normal fish hunting video, that is, a screen that is scrolled sequentially, and each information at that time is displayed on the screen as numerical values and / or symbols. High visibility can be obtained.
[0057]
Further, it is possible to use the fish detection information by simply connecting all the fish detectors equipped with the NMEA connector without any modification.
[0058]
Moreover, only the data to be displayed on the fisherman's reception display terminal is obtained from the fish detection information group, typically NMEA data, which is serially output as digital data every predetermined time and the information is represented by numerical values. Since data is extracted and transmitted after data editing, data processing at a receiving display terminal that is required to be simple, small, and inexpensive can be reduced. Therefore, the reception display terminal possessed by each angler can be made small and inexpensive. Furthermore, an external output terminal is provided on the reception display terminal, and a plurality of information including water depth information, fish depth information, and fish quantity information can be output to the outside. It becomes possible to use.
[0059]
In addition, when the output interval of NMEA data is long (for example, 2 seconds interval, 4 seconds interval), data is extracted by the data editing unit and interpolation processing of water depth data is performed to smooth the water depth before transmission. To do. Therefore, a smooth fish search image can be displayed without increasing the data processing burden associated with the interpolation processing at the reception display terminal.
[0060]
In addition, transmission of fish detection information from the wireless transmission device is performed by specific low power wireless. Since the fish detection information only needs to be transmitted to a fisherman or the like in the same fishing boat, the distance for this is at most about 20 to 30 m, and there is no problem in transmission by the specific low power radio. And, by transmitting by specific low-power radio, it is possible to transmit the fish detection information to all fishers who need the fish detection information wirelessly arbitrarily and easily without being restricted by the Radio Law as in the conventional example. Can do.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration of a fish detection information wireless transmission display system of the present invention.
FIG. 2 is a diagram showing a configuration of the wireless transmitter.
FIG. 3 is a diagram showing a configuration of the reception display terminal.
FIG. 4 is a diagram showing a configuration of a display unit in a reception display terminal.
FIG. 5 is a diagram showing a display screen of a reception display terminal.
FIG. 6 is a diagram for explaining the effect of smoothing processing on water depth data.
FIG. 7 is a diagram showing a configuration of a conventional wireless transmission fish finder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Fish finder 11 Fish finder 12 Water temperature sensor 13 GPS antenna 20 Radio transmitter 21 Data edit part 22 Modulation part 23 Radio transmission part 30, 30A Reception display terminal 31 Radio reception part 32 Demodulation part 33 Data output part 40 Display part 41 Input interface 42 CPU
43 RAM
44 LCD driver 45 LCD display

Claims (6)

A fish detection information wireless transmission display system used inside a ship,
It is NMEA data that consists of NMEA standard data and optional data including information on fish depth and fish quantity, and is based on NMEA standards, and each piece of information is expressed numerically. A fish finder that outputs serially every predetermined time;
A fish detection information group from the fish detection device is input, and only information necessary as display fish detection information including water depth information, fish depth information, and fish quantity information is extracted from the fish detection information group, and information that is not displayed is extracted. A wireless transmission device having data editing means to be deleted, and wireless transmission means for modulating the display fish finder detection information extracted by the data editing means and transmitting the information to the inside of the ship by specific low-power radio;
Radio receiving means for receiving radio waves transmitted by the specific low-power radio from the radio transmitting apparatus inside the ship, and demodulating a fish detection information group for display in which each information is represented by a numerical value, and demodulated Based on the display fish detection information group including the water depth information, fish depth information and fish quantity information, the seafloor line is displayed on the screen using the history of the water depth information, and the water depth, fish depth, fish school on the screen. One or more reception display terminals having display means for displaying the fish detection information including the quantity by numbers or symbols ;
A fish detection information wireless transmission display system. The fish detection information wireless transmission display system according to claim 1 , wherein the data editing means further performs smoothing processing by interpolation according to a water depth value obtained every predetermined time for the extracted water depth information. It consists of NMEA standard data and optional data including information on fish depth and fish quantity, and NMEA data conforming to the NMEA standard. Each of these information is expressed numerically, and is digital data every predetermined time. Data editing means for extracting only information necessary for display fish detection information including water depth information, fish depth information, and fish quantity information from serially input fish detection information groups, and deleting information not to be displayed , and this data editing A wireless transmission device comprising: a wireless transmission device that modulates the fish detection information for display extracted by the device and transmits the information by specific low-power wireless transmission. The radio transmission apparatus according to claim 3 , wherein the data editing unit further performs smoothing processing by interpolation according to a water depth value obtained every predetermined time for the extracted water depth information. Standard data and fish depth NMEA standards, is extracted from the NMEA data conforming to the NMEA standard consists option data including information of fish weight as information necessary for display, water depth information arranged serially at predetermined time intervals, Radio receiving means for receiving and demodulating radio waves modulated by display fish detection information including fish depth information and fish quantity information, and a plurality of display fish schools including demodulated water depth information, fish depth information and fish quantity information Display means for displaying the sea bottom line on the screen using the history of the water depth information based on the detection information, and displaying the fish detection information for display including the water depth, the fish school depth, and the fish quantity on the screen by a number or a symbol. A receiving display terminal characterized by comprising: 6. The reception display terminal according to claim 5 , further comprising an output terminal for outputting display fish detection information including the demodulated water depth information, fish depth information, and fish quantity information to the outside.

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