JP4929441B2 - Underwater detector - Google Patents

Description

The present invention relates to an underwater detection device for discriminating fish length and fish type based on a reflection signal from a fish.

In order to investigate the amount of resources in the sea, a measuring fish finder using an acoustic technique has been conventionally used (Patent Document 1). This measuring fish finder obtains the ratio of the sound pressure level of the ultrasonic wave transmitted from the transducer and the sound pressure level of the reflected wave reflected by the fish, that is, the reflection strength TS (Target Strength). The body length of the fish is calculated from the obtained reflection intensity TS.
Japanese Patent Laid-Open No. 02-262082

It is thought that the sound pressure level of the reflected wave that comes back from the fish is mainly reflected from the surface of the body, body surface, and skeleton. However, the locational relationship and form of the parts of the Japanese blackhead, body surface, and skeleton differ depending on the fish species.
Therefore, it is difficult to say that the correlation between the reflection intensity TS and the fish body length is the same for all fish species, and it is difficult to determine the exact fish body length and fish species using only the reflection intensity TS from the fish.

The present invention has been made in view of such problems, and an object of the present invention is to provide a new fish body length and fish species discrimination method for more accurately discriminating fish body length and fish species.

In order to solve the above-described problems, the present invention provides a transmission unit that transmits a sound wave having a predetermined pulse width, and a reception unit that receives a reflected wave from a target with respect to the transmission signal and detects an envelope of the reception signal And an extraction unit for extracting a reflection signal from a single fish from a reception signal output from the reception unit, and a waveform of the reflection signal continuous at a predetermined signal level or more from a temporal change of the reflection signal from the single fish An information generation unit that acquires information and generates information on the extracted single fish based on the waveform information is provided.

The waveform information is generated, for example, in a maintenance time during which the signal level of the reflected signal maintains a value equal to or higher than a predetermined signal level, or a period during which the signal level of the reflected signal maintains a value higher than a predetermined signal level There is a peak number of the reflected signal, and the information generation unit generates information on the fish using these pieces of information.

Moreover, the information regarding the said fish is fish body length information, fish species information, and fish posture information, for example. When the posture information of the fish is generated by the information generation unit, it is possible to select an optimum reflection signal from a single fish used for generating fish body length information and fish type information based on the posture information of the fish. is there.

Further, according to the present invention, an LPF may be provided in front of the information generation unit so that a reflection signal from a single fish is smoothed. As a result, even when the envelope of the reflected signal from a single fish is broken into two or three, the information generator accurately reflects the reflected signal from a single fish that is continuous at a predetermined signal level or higher. It is possible to detect and to generate more accurate information about the fish.

The predetermined signal level is, for example, the standardized signal level of the reflected signal with the maximum signal level of the reflected signal from a single fish, and the maximum signal level of the normalized reflected signal is 1 / N ( N> 1). Note that normalization with the maximum value of the signal level of the reflected signal is not an essential requirement, and a predetermined signal level may be calculated without normalization.

Further, the present invention includes a transmission unit for transmitting sound waves having a predetermined pulse width, a receiver for receiving a reflected wave from a target to the transmission signal, detects the envelope of the received signal, from the reception unit An extraction unit that extracts a reflection signal from a single fish from an output reception signal; and an information generation unit that generates information about the extracted single fish based on temporal continuity of the reflection signal from the single fish; It is characterized by providing.

Further, the present invention includes a transmission unit for transmitting sound waves having a predetermined pulse width, a receiving unit that receives a reflected wave from the single fish to the transmission signal, detects the envelope of the received signal, from the reception unit An extraction unit that extracts a reflection signal from a single fish from an output reception signal, and an information generation unit that generates information about the extracted single fish based on the number of peaks of the reflection signal from the single fish It is characterized by.

According to the present invention, information on fish such as fish length information and fish type information is generated based on temporal changes in the reflected signal from a single fish, that is, on the waveform information of the reflected signal. This makes it possible to perform fish length detection and fish type discrimination by a new method different from fish length detection and fish type discrimination based on the reflection intensity TS.

(Embodiment 1)
Hereinafter, an underwater detection device according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an example of the configuration of the underwater detection device according to Embodiment 1 of the present invention.
1, the underwater detection device according to Embodiment 1 of the present invention includes a transmitter / receiver 1, a transmission / reception switching unit 2, a transmission unit 3, a reception unit 4 having a detection unit 5, an extraction unit 6, and information. The generating unit 7, the drawing processing unit 8, and the display unit 9 are configured.

The transmitter / receiver 1 converts a transmission electric signal from the transmission unit 3 into a sound wave and transmits the sound wave, and converts an ultrasonic echo returned from the water into an electric signal when receiving the wave. The transmission / reception switching unit 2 is a circuit that switches a signal path between transmission and reception. The transmission / reception switching unit 2 allows only a transmission signal to pass during transmission and allows only a reception signal to pass during reception.

The transmission unit 3 is an electric signal generation unit for emitting a sound wave having a predetermined pulse width, and supplies the generated signal to the transmitter / receiver 1. The receiving unit 4 receives the electrical signal converted by the transducer 1, extracts a received signal in a predetermined frequency band, and detects an envelope of the received signal by the detecting unit 5.

The extraction unit 6 extracts a reflection signal from a single fish using the reception signal output from the reception unit 4. Various techniques have been devised for detecting the reflected signal of a single fish. For example, a technique for detecting whether a single fish or a school of fish based on the width and signal level of a reflected wave from a target is common.

The information generation unit 7 acquires waveform information of a reflected signal that is continuous at a predetermined signal level or higher among the reflected signals from a single fish, and generates information about the fish based on the waveform information. Here, the information related to fish includes various information related to the extracted single fish such as fish body length information, fish type information, and fish posture information. Here, the fish body length is information relating to the size of the fish body, and specifically means any one of the fork length, the fish body height, the fish body width, or a plurality of such information.

The drawing processing unit 8 generates an echo video representing underwater information such as the sea bottom and a school of fish based on the reception signal output from the reception unit 4, and the fish length generated by the information generation unit 7 along with the generated echo video Information on fish such as fish species is drawn on the display unit 9.

Next, the information generation unit 7 will be described in more detail with reference to FIGS.
The information generation unit 7 includes a measurement unit 71, a counting unit 72, and an information processing unit 73. Here, the information generation unit 7 includes the measurement unit 71 and the counting unit 72 as an example, but the information generation unit 7 includes only one of the measurement unit 71 and the counting unit 72. It may be.

The measurement unit 71 receives a reflection signal from a single fish and measures a maintenance time during which the signal level of the reflection signal maintains a value equal to or higher than a predetermined signal level. The predetermined signal level used by the measurement unit 71 to measure the maintenance time is calculated for each reflected signal output from the extraction unit 6. The predetermined signal level is a value obtained by normalizing the signal level of the reflected signal with the maximum value of the signal level of the reflected signal and 1 / N (N> 1) of the maximum value of the normalized signal level of the reflected signal. The value of N is more preferably 10 or more. Although an example in which the predetermined signal level is calculated from the maximum value of the standardized signal level of the reflected signal is shown here, the predetermined signal level may be calculated without performing normalization.

The counting unit 72 receives a reflection signal from a single fish as in the measurement unit 71 described above, and the number of peaks of the reflection signal generated during a period in which the signal level of the reflection signal maintains a value equal to or higher than a predetermined signal level. Count. The predetermined signal level used by the counting unit 72 to count the number of peaks is calculated in the same manner as the measuring unit 71 described above. Note that the value of N used to calculate the predetermined signal level may be the same value as that used in the measurement unit 71, or a different value.

The information processing unit 73 generates information about the fish from the maintenance time detected by the measurement unit 71 and the number of peaks detected by the counting unit 72 based on statistical data collected in advance.

FIG. 2 is a schematic diagram showing a state of reflection of an ultrasonic signal incident on a single fish.
In general, it is considered that the reflected waves from fish are mainly reflected from the sea bass, the body surface, and the skeleton. As shown in FIG. 2, when an ultrasonic pulse with sufficient resolution compared to the size of a single fish is incident on the single fish, relatively large reflected waves are generated at a plurality of positions such as a Japanese black body, a body surface, and a skeleton. Is considered to occur.

At this time, since the distances from the ultrasonic signal transmission source to the plurality of signal reflection positions are different from each other, the reflected waves are generated at different timings as shown in FIG. In addition, since the reflection intensity and reflection cross-sectional area of the ultrasonic signal are different for the reflection target, body surface, skeleton, etc., the signal level of the reflected wave generated at each signal reflection position is also different. become.

Therefore, the present invention considers that the reflected signal from a single fish is a composite signal of a plurality of reflected waves having different timings and different reflection intensities, and the reflected signal from a single fish. Information on fish such as fish length information and fish type information is generated using the time variation of the signal, that is, the waveform information of the reflected signal.

Hereinafter, the content of the present invention will be described more specifically.
FIG. 3 is a diagram showing reflected signals and their envelopes measured from three kinds of single fish fixed by anesthesia in a water tank.

The measurement result of FIG. 3 is a measurement result of the reflected signal when an ultrasonic signal is irradiated from a direction perpendicular to the water surface to a horse mackerel, a tie, and a mackerel that are fixed horizontally to the water surface at a depth of 2 m. The reflected waves from five solids having different lengths, fish heights, and fish widths are shown for each fish type. From left to right, the reflection signals and envelopes of horse mackerel, tie, and mackerel are shown. In this experiment, hand dolphin clicks were used as transmission signals. The click of the bottlenose dolphin used in the experiment has a peak frequency of 90 kHz, a pulse time width (half the peak value) of about 26 μs, and a 3 dB bandwidth of 22.5 kHz.

As shown in FIG. 3, a reflected wave obtained from a single fish is received as a composite wave of a plurality of reflected waves generated on a sea bass, a body surface, a skeleton, etc., and has a different waveform for each solid.

FIG. 4 is a diagram showing the result of analyzing the waveform of the reflected signal from a single fish, focusing on the temporal continuity and the number of peaks of the reflected wave, and is measured by the underwater detection device according to the first embodiment of the present invention. The maintenance time measured by the unit 71 and the number of peaks counted by the counting unit 72 are shown.
A straight line crossing the envelope of each reflected signal in FIG. 4 is a predetermined signal level calculated by the measuring unit 71 and the counting unit 72 (hereinafter referred to as “threshold” as appropriate), and the maximum value of each reflected signal is represented by 1 / N (N> 1). Here, the threshold value is calculated with N = 10 in both the measuring unit 71 and the counting unit 72.

In addition, since the envelope of each reflected signal shown in FIG. 4 is a reflected signal obtained from a single fish fixed in the aquarium, only the reflected signal from the single fish is included. Therefore, even if the envelope is broken into two or three, for the sake of convenience, the maintenance time is measured and the number of peaks is counted on the assumption that the threshold has been exceeded. A countermeasure against the cracking of the envelope will be described in Embodiment 2 and Embodiment 3 described later.

The measurement unit 71 measures a maintenance time during which the signal level of the reflected signal is maintained at a value equal to or higher than a predetermined signal level using the calculated threshold value. Two arrows marked on the normal line of each reflected signal indicate the measurement start time and end time by the measurement unit 71. Further, the number written at the upper left of each envelope indicates the maintenance time measured by the measuring unit 71.

FIG. 5 shows the relationship between the maintenance time and the fork length measured by the measuring unit 71 and the relationship between the maintenance time and the fish height.
FIG. 5A shows the relationship between the maintenance time and the fish body height. In FIG. 5 (a), the vertical axis represents the maintenance time, and the horizontal axis represents the fish body height. The average values of data obtained from different solids for the horse mackerel, Thai, and mackerel fish types are plotted.

In this experimental result, as shown in FIG. 5A, the relationship between the maintenance time measured by the measuring unit 71 and the fish height is almost proportional, and the maintenance time becomes longer as the fish height increases. From this, it can be said that the information processing unit 73 can calculate information on the fish such as the fish height and the fish type based on the correlation between the maintenance time and the fish height. That is, the information processing unit 73 holds a function representing the correlation between the maintenance time and the fish height in advance, and the extraction time is extracted by inputting the maintenance time output from the measurement unit 71 into the function. It is possible to calculate the height of a single fish. The correlation between the maintenance time and the fish height is not limited to a proportional relationship.

FIG. 5B shows the relationship between the maintenance time and the fork length. In FIG. 5B, the vertical axis is the maintenance time, and the horizontal axis is the fork length, and the average values of data obtained from different solids are plotted for horse mackerel, Thai, and mackerel fish types.

The maintenance time measured by the measuring unit 71 is considered to represent the vertical thickness of a single fish, that is, the fish height. However, the outline of many fishes is substantially similar, and even if the result shown in FIG. 5B is seen, there is a substantially proportional correlation between the maintenance time measured by the measuring unit 71 and the fork length.

Therefore, the information processing unit 73 stores in advance a function representing the correlation between the maintenance time and the fork length, as in the case of calculating the fish height described above, and uses the maintenance time output from the measurement unit 71 as the function. It is also possible to estimate the fork length of a single fish extracted by the extraction unit 6. The correlation between the maintenance time and the fork length is not limited to a proportional relationship.

Further, the information processing unit 73 uses not only the maintenance time measured by the measurement unit 71 but also the information of the reflection intensity TS from the single fish, and uses the fish length information such as the fork length and the fish body height and the fish type information. You may make it produce | generate. Thereby, since the information processing part 73 can produce | generate the information regarding fish using more verification information, it becomes possible to obtain more exact fish body length information and fish kind information.

Next, the counting unit 72 provided in the information generating unit 7 counts the number of peaks of the reflected signal generated during the period in which the signal level of the reflected signal is maintained using the calculated threshold value. The vertical line drawn to the peak position of the envelope of each reflected signal in FIG. 4 indicates the peak position of the reflected signal, and the counting unit 72 counts the number of peaks.

FIG. 6 shows the relationship between the number of peaks measured by the counting unit 72 and the fork length, and the relationship between the number of peaks and the fish height.
FIG. 6A is a diagram showing the relationship between the number of peaks and the fish height. In FIG. 6 (a), the vertical axis represents the number of peaks and the horizontal axis represents the fish body height, and the average values of data obtained from different solids are plotted for horse mackerel, Thai, and mackerel fish types.

In the present experimental results, as shown in FIG. 6A, the relationship between the number of peaks counted by the counting unit 72 and the height of a single fish is almost proportional, and the number of peaks increases as the height of the fish increases. . Therefore, it can be said that the information processing unit 73 can calculate information on the fish such as the fish height and the fish type based on the correlation between the peak number and the fish height. That is, the information processing unit 73 holds a function representing the correlation between the number of peaks and the fish height in advance, and the number of peaks output from the counting unit 72 is input to the function to be extracted by the extraction unit 6. It is possible to calculate the height of a single fish. The correlation between the number of peaks and the fish height is not limited to a proportional relationship.

FIG. 6B shows the relationship between the number of peaks and the fork length. In FIG. 6 (b), the vertical axis represents the number of peaks and the horizontal axis represents the fork length, and the average values of data obtained from different solids are plotted for horse mackerel, Thai, and mackerel fish types.

The number of peaks counted by the counting unit 72 is considered to represent the vertical thickness of a single fish, that is, the height of the fish body, as in the case of FIG. However, the outer shape of many fishes is substantially similar, and even if the result shown in FIG. 6B is seen, there is a substantially proportional correlation between the number of peaks counted by the counting unit 72 and the fork length.

Therefore, as in the case of calculating the above-described fish height, the information processing unit 73 holds a function representing the correlation between the peak number and the fork length in advance, and uses the peak number output from the counting unit 72 as the function. It is also possible to calculate the fork length of a single fish extracted by the extraction unit 6. The correlation between the number of peaks and the fork length is not limited to a proportional relationship.

Further, the information processing unit 73 uses not only the number of peaks counted by the counting unit 72 but also information on the maintenance time measured by the measuring unit 71 and the reflection intensity TS from a single fish, and the fork length, the fish height, etc. The fish body length information and fish type information may be generated. Thereby, since the information processing part 73 can verify the information regarding fish using more verification information, it becomes possible to perform more accurate fish body length detection and fish kind discrimination | determination.

Next, the relationship between the reflection signal from a single fish and the posture angle of the single fish is shown.
FIG. 7 is a diagram showing a reflection signal and its envelope measured by changing the posture angle of a single fish fixed by anesthesia in a water tank.

The measurement results shown in FIG. 7 show the reflected signal when the posture of a single fish fixed by anesthesia in the water tank is changed in increments of 10 degrees from -90 degrees to +90 degrees and an ultrasonic signal is irradiated from the direction perpendicular to the water surface. It is a measurement result. Here, the case where the sound wave is incident vertically from the back direction is 0 degree, the case where the sound wave is incident from the head direction is plus, and the case where the sound wave is incident from the tail direction is minus. The transmission signal used in this experiment is a bottlenose dolphin clicks similar to that described in FIG.

As shown in FIG. 7, a reflected wave obtained from a single fish is received as a composite wave of a plurality of reflected waves generated from a sea bass, a body surface, a skeleton, etc., and has a different waveform for each posture of the single fish.

FIG. 8 is a diagram showing the relationship between the maintenance time and the posture angle measured by the measurement unit 71 of the underwater detection device according to Embodiment 1 of the present invention. In FIG. 8, the vertical axis represents the maintenance time, and the horizontal axis represents the posture angle.
As shown by the dotted line in FIG. 8, the relationship between the maintenance time and the posture angle tends to be shortened as the posture angle approaches 0 degrees.

FIG. 9 is a diagram showing the relationship between the number of peaks counted by the counting unit 72 of the underwater detection device according to Embodiment 1 of the present invention and the attitude angle. In FIG. 9, the vertical axis represents the number of peaks, and the horizontal axis represents the posture angle.
As shown by the dotted line in FIG. 9, the relationship between the number of peaks and the posture angle tends to decrease as the posture angle approaches 0 degrees.

FIG. 10 is a diagram showing the relationship between the maximum signal level of the reflected signal from a single fish and the posture angle. In FIG. 10, the vertical axis represents the maximum signal level, and the horizontal axis represents the posture angle.
As shown by the dotted line in FIG. 10, the relationship between the maximum signal level and the posture angle tends to increase as the posture angle approaches 0 degrees. The detection of the maximum level of the reflection signal from a single fish can be realized by providing a detection unit for detecting the maximum level of the reflection signal in parallel with the measurement unit 71 and the counting unit 72 described above.

As described above, as shown in FIGS. 8 to 10, there is a correlation between the waveform information of the reflected signal obtained from the single fish and the posture of the single fish, and the information processing unit 73 maintains the detection detected from the reflected signal obtained from the single fish. The posture of the fish can be calculated based on waveform information such as time, the number of peaks, and the maximum signal level of the reflected signal. That is, the information processing unit 73 stores in advance information indicating the relationship between the information such as the maintenance time, the number of peaks, the maximum signal level of the reflected signal, and the posture of the single fish, Based on the output information from the component that generates the waveform information of the reflected signal from the single fish, the posture of the single fish extracted by the extraction unit 6 can be estimated.

In addition, the information generation unit 7 can select a reflection signal for generating fish length information and fish type information based on the posture information of the fish generated by the information processing unit 73. Thereby, since the information processing part 73 can produce | generate fish body length information and fish type information using the optimal reflection signal for the production | generation of fish body length information or fish type information, it becomes possible to obtain the stable result. Become. Such a reflection signal selection process is particularly suitable when a plurality of reflection signals are obtained from the same single fish.

Moreover, the information generation part 7 can also estimate the advancing direction of a fish using the posture information of the fish produced | generated by the information processing part 73, and can calculate the reliability of the calculated fish body length information and fish kind information. It is.

(Embodiment 2)
Next, an underwater detection device according to Embodiment 2 of the present invention will be described.
In the underwater detection device according to Embodiment 2 of the present invention, even when the envelope of the reflected signal from a single fish is broken into two or three, the measurement of the maintenance time and the counting of the number of peaks are more accurate. A technique that can be performed well will be described.

FIG. 11 is a block diagram showing an example of the configuration of the underwater detection device according to the second embodiment of the present invention.
The underwater detection device according to Embodiment 2 of the present invention includes a transducer 1, a transmission / reception switching unit 2, a transmission unit 3, a reception unit 4 having a detection unit 5, an extraction unit 6, and an information generation unit 7. , A drawing processing unit 8, a display unit 9, and an LPF (low-pass filter) 10. In addition, the same code | symbol is attached | subjected about the component similar to the underwater detection apparatus by Embodiment 1 of this invention mentioned above using FIG. 1, and description is abbreviate | omitted here.

The LPF 10 is provided in the preceding stage of the information generation unit 7 and plays a role of smoothing at least an input signal. As a function used for the LPF 10, for example, a Hanning window or a Gauss window can be considered. Although FIG. 11 shows an example in which the LPF 10 is provided in the subsequent stage of the extraction unit 6, the LPF 10 may be provided in the previous stage of the extraction unit 6.

FIG. 12 shows the result of LPF processing by convolution of the reflected signal from a single fish using a Hanning window with a window length of 50 μs.
FIG. 12A shows an envelope after low-pass filter processing, and FIG. 12B shows a Hanning window used for low-pass filter processing.

As shown in FIG. 12 (a), by subjecting the reflected signal from a single fish to LPF processing, the envelopes that have been broken into two or three are rounded to form one continuous envelope. Thereby, even when the envelope of the reflected signal from a single fish is broken into two or three, the measurement of the maintenance time by the measuring unit 71 and the counting of the number of peaks by the counting unit 72 are performed more accurately. Therefore, the information processing unit 73 can generate more accurate information about fish such as fish length information and fish type information.

(Embodiment 3)
Next, an underwater detection device according to Embodiment 3 of the present invention will be described.
In the underwater detection device according to the third embodiment of the present invention, a countermeasure different from the underwater detection device according to the second embodiment of the present invention will be described.

When the envelope of the reflection signal from a single fish is broken into two or three, it is within a predetermined time width in addition to the method using the LPF as described with reference to FIGS. The reflection signal may be regarded as a reflection signal from a single fish, and the measurement of the maintenance time by the measurement unit 71 and the counting of the number of peaks by the counting unit 72 may be performed. The configuration of the underwater detection device is the same as that of the underwater detection device according to the first embodiment described above except for the processing contents of the measurement unit 71 and the counting unit 72, and thus description thereof is omitted here.

That is, the measuring unit 71 determines and holds in advance the time width of the reflected signal obtained from a single fish. This time width is calculated, for example, by statistically processing the reflection signal of a single fish. And the measurement part 71 detects the reflected signal more than the predetermined | prescribed signal level within the said time width by making the maximum level of the signal level of the reflected signal from a single fish into the center of the said time width. The measuring unit 71 measures the time from the first point to the last point where a reflected signal equal to or higher than the signal level is obtained, and outputs this as the maintenance time. Thereby, even if it is a case where the envelope of the reflected signal from a single fish is broken into two or three, the measuring unit 71 can accurately measure the maintenance time.

In the counting unit 72 as well, as with the measuring unit 71, the time width of the reflected signal obtained from a single fish is determined and held in advance. This time width is calculated, for example, by statistically processing the reflection signal of a single fish. Then, the counting unit 72 sets the maximum level of the signal level of the reflected signal from the single fish as the center of the time width, and the number of peaks equal to or higher than the predetermined signal level among the peaks of the reflected signal generated within the time width. Count. Thereby, even if the envelope of the reflected signal from a single fish is broken into two or three, the counting unit 72 can count the number of peaks with high accuracy.

As described above, the information processing unit 73 uses the maintenance time measured by the measurement unit 71 and the number of peaks counted by the counting unit 72 to more accurately generate information about fish such as fish length information and fish type information. It becomes possible.

The underwater detection device according to the present invention can be applied to devices such as a sonar in addition to a fish finder.
In addition, the present invention can be freely modified within the scope of the present invention described in each embodiment of the present invention, and is not limited to the contents described in each embodiment of the present invention. .

The block diagram which shows an example of a structure of the underwater detection apparatus by Embodiment 1 of this invention. Schematic diagram for explaining the state of reflection of an ultrasonic signal incident on a single fish The figure which shows the reflection signal and its envelope which were measured from three kinds of single fish fixed by anesthesia in the aquarium The figure which shows the result of analyzing the waveform of the reflected signal from a single fish focusing on the temporal continuity and the number of peaks of the reflected wave The figure which shows the relationship between the maintenance time and the fork length which the measurement part of the underwater detection apparatus by Embodiment 1 of this invention measured, and the relationship between a maintenance time and fish body height The figure which shows the relationship between the peak number and the fork length which the counting part of the underwater detection apparatus by Embodiment 1 of this invention measured, and the relationship between a peak number and fish body height The figure which shows the reflected signal and the envelope which were measured by changing the posture angle of the single fish fixed by anesthesia in the aquarium The figure which shows the relationship between the maintenance time which the measurement part of the underwater detection apparatus by Embodiment 1 of this invention measured, and a posture angle. The figure which shows the relationship between the peak number which the counter of the underwater detection apparatus by Embodiment 1 of this invention counted, and attitude | position angle. The figure which shows the relation between the maximum signal level of the reflection signal from the single fish and the posture angle The block diagram which shows an example of a structure of the underwater detection apparatus by Embodiment 2 of this invention. Explanatory drawing for demonstrating the LPF process of the underwater detection apparatus by Embodiment 2 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmitter / receiver 2 Transmission / reception switching part 3 Transmission part 4 Reception part 5 Detection part 6 Extraction part 7 Information generation part 8 Drawing process part 9 Display part 10 LPF

Claims (11)

A transmitter for transmitting a sound wave having a predetermined pulse width ;
A reception unit that receives a reflected wave from a target with respect to a transmission signal and detects an envelope of the reception signal ;
An extraction unit that extracts a reflection signal from a single fish from the reception signal output from the reception unit;
An information generation unit that acquires waveform information of a reflected signal that is continuous at a predetermined signal level or more from a time change of the reflected signal from the single fish, and generates information about the extracted single fish based on the waveform information; An underwater detection device comprising:
The underwater detection device according to claim 1,
The waveform information includes a maintenance time during which the signal level of the reflected signal maintains a value equal to or higher than the predetermined signal level,
The underwater detection device, wherein the information generation unit generates information on the single fish based on the maintenance time. The underwater detection device according to claim 1,
As the waveform information, including the number of peaks of the reflected signal generated during a period in which the signal level of the reflected signal maintains a value equal to or higher than the predetermined signal level,
The underwater detection device, wherein the information generation unit generates information on the single fish based on the number of peaks. The underwater detection device according to claim 1,
The waveform information is generated in a maintenance time during which the signal level of the reflected signal maintains a value equal to or higher than the predetermined signal level, and a period during which the signal level of the reflected signal maintains a value higher than the predetermined signal level. Including the number of peaks in the reflected signal,
The underwater detection device, wherein the information generation unit generates information on the single fish from the maintenance time and the number of peaks. In the underwater detection device according to any one of claims 2 to 4,
The underwater detection device characterized in that the information on the single fish is at least one of fish length information, fish species information, and fish posture information. The underwater detection device according to claim 5,
The underwater detection device, wherein the information generation unit selects a reflection signal from a single fish used for generation of the fish body length information or the fish species information based on the posture information of the fish. In the underwater detection apparatus in any one of Claim 1 to 6,
An LPF is provided in front of the information generator,
The underwater detection device, wherein the information generation unit generates information about fish using a signal output from the LPF. In the underwater detection apparatus in any one of Claim 1 to 7,
The underwater detection device, wherein the predetermined signal level is a value obtained by multiplying a maximum value of the signal level of the reflected signal by 1 / N (N> 1). In the underwater detection apparatus in any one of Claim 1 to 7,
The predetermined signal level is a value obtained by standardizing the signal level of the reflected signal with the maximum value of the signal level of the reflected signal and 1 / N (N> 1) of the maximum value of the normalized signal level of the reflected signal. Underwater detector characterized by being A transmitter for transmitting a sound wave having a predetermined pulse width ;
A receiving unit that receives a reflected wave from a target with respect to a transmission signal and detects an envelope of the reception signal ;
An extraction unit that extracts a reflection signal from a single fish from the reception signal output from the reception unit;
An underwater detection device comprising: an information generation unit configured to generate information on the extracted single fish based on the temporal continuity of the reflection signal from the single fish. A transmitter for transmitting a sound wave having a predetermined pulse width ;
A receiving unit that receives a reflected wave from a target with respect to a transmission signal and detects an envelope of the reception signal ;
An extraction unit that extracts a reflection signal from a single fish from the reception signal output from the reception unit;
An underwater detection device comprising: an information generation unit configured to generate information on the extracted single fish based on the number of peaks of the reflection signal from the single fish.

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