JP2016212042A - Information collection method using sound of deposition layer under water bottom and information collection device using sound of deposition layer under water bottom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information collection method that responds to an increasing desire to grasp spatial information in a deposition layer under the water bottom in detail in non-destruction without depending on a destructive method such as the columnar coring.SOLUTION: An information collection method of the present invention is characterized by: constituting a frame structural base of a three-dimensional structure capable of landing on a water bottom using multiple frame members; scanning an acoustic measurement unit comprising a wave transmitter and wave receivers in the XY direction in a landing state; and thereby collecting the information of the deposition layer under the water bottom using sound with high accuracy. The acoustic measurement unit forms sharp directivity downward in the Z-direction perpendicular to the XY direction, and thereby can collect information of high resolution. The acoustic measurement unit forms the sharp directivity by beam forming using the wave transmitter and multiple wave receivers annularly disposed in the circumference, and thereby can obtain good sharp directivity.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for collecting information on a sedimentary layer under a water bottom such as a seabed, a lake bottom, or an artificial structure by sound.

  In recent years, there has been an increasing demand for non-destructive detailed information on the spatial information in sediment layers beneath the bottom of the water, such as the ocean floor, lake bottom, and man-made structures, without relying on destructive methods such as columnar coring. It covers a wide range of subjects such as the thickness of floating mud, soft mud, aquatic plants, root vegetables, etc., distribution of benthic organisms, geological changes in the depth direction, and measurement of the shape of buried objects such as sunken ships and weapons. Crossing.

  By the way, various types of sonar using sound waves have been widely known as non-destructive collection methods for collecting information in a deposition layer under a water bottom.

  For example, in Patent Document 1, in a configuration in which an ultrasonic transmitter / receiver is supported on a moving body such as an autonomous unmanned submersible (AUV) that travels in the sea, correction of the movement of the moving body due to disturbance such as tidal current is corrected. Synthetic aperture sonar is described.

  Also, Patent Document 2 discloses a mine that visualizes and detects underwater information by sequentially receiving reflected sound waves from the bottom of the water by a sound wave transmitting unit and a receiving unit supported by a moving body that travels in water or on water. Describes an underwater acoustic imaging device equipped with a technique for determining whether a mine is a sinking mine or a buried mine.

Japanese Patent No. 5497302 Japanese Patent No. 5470146

  As described above, a conventional apparatus using sound such as sonar detects a target object by supporting a transducer on a moving body such as a ship, ROV, AUV or the like on water or in water. However, since it fluctuates under the influence of tidal currents, waves or winds, it is difficult to perform highly accurate detection. For this reason, although the detection target range is wide, the target object that can be detected is limited to a relatively large object such as a mine as described in Patent Document 2, for example. In addition, since the data quality changes depending on the weather conditions at the time of measurement, the reproducibility of data by repeated measurement is low. For this reason, it is difficult to monitor the change over time of the detection target.

  For this reason, as well as collecting information on relatively small target objects (for example, 2-5 cm in diameter for lotus roots) such as benthic organisms such as root vegetables and shellfish in the sedimentary layer under the bottom of the water, they can be collected over time. The motivation to use sound to monitor changes could never occur before.

  On the other hand, as a result of earnest research, the present inventor has collected non-destructive information on the deposited layer including relatively small objects by collecting information on the deposited layer under the bottom of the water by using sound rationally. In addition, the present inventors have conceived a method and apparatus capable of measuring with high resolution and high reproducibility, and are intended to solve the conventional problems.

  That is, in the present invention, in order to solve the above-mentioned problem, a frame structure base body having a three-dimensional structure that can be attached to the water bottom is constituted by a plurality of frame members, and a transmitter and An acoustic measurement unit including a receiver is supported by an XY drive mechanism that can move in an XY direction corresponding to the spreading direction of the water bottom surface in a state where the frame structure base is bottomed. An acute directivity is formed downward in the Z direction orthogonal to the XY direction, and in a state where the frame structure base is attached to the bottom of the water by weight, the acoustic measuring unit is scanned in the XY direction to generate an acoustic reflection signal. This paper proposes a method for collecting information by acoustics of the sediment layer beneath the bottom of the water that collects information on the sediment layer beneath the bottom of the water.

  According to the present invention, in the above method, it is proposed that the acoustic measurement unit forms a sharp directivity by beam forming from a transmitter and a plurality of receivers arranged in a ring around the transmitter.

  According to the present invention, in the above method, the acoustic reflection signal data collected by scanning the acoustic measurement unit in the XY directions is processed to construct C-mode plane images at a large number of positions in the Z direction. We propose to build a three-dimensional acoustic image by stacking C-mode plane images. Further, in this method, it is proposed to display the constructed three-dimensional sound image by performing an alpha blend process.

  According to the present invention, in the above method, the frame structure base has a rectangular parallelepiped configuration, and the XY drive mechanism is a movable frame member that movably supports the acoustic measurement unit between the opposed frame members on the upper side in the bottomed state. Is proposed, and the moving frame member is configured to be movable along the opposing frame member.

  Further, the present invention proposes a method for collecting information by acoustics of the sedimentary layer under the water bottom, which is configured to support the acoustic measurement unit so as to be movable in the Z direction.

  Further, in the present invention, a three-dimensional frame structure base configured by a plurality of frame members and capable of landing on the bottom of the water, an acoustic measurement unit including a transmitter and a receiver, and the acoustic measurement unit are connected to a frame. An XY drive mechanism which supports the structure base so as to be movable in the XY direction corresponding to the spreading direction of the bottom surface of the water, and controls the XY drive mechanism and the acoustic measurement unit. The sound measuring unit proposes an information collecting device based on the sound of the sedimentary layer below the bottom of the water surface, the directivity of which is formed downward in the Z direction perpendicular to the XY direction. .

  In the present invention, the apparatus further includes an image construction unit that constructs a three-dimensional acoustic image from the collected acoustic reflection signal data. The image construction unit processes the collected acoustic reflection signal data. , Information by acoustic of a sedimentary layer under water bottom comprising means for constructing C-mode plane images at a plurality of positions in the Z direction and means for constructing a three-dimensional acoustic image by stacking the constructed C-mode plane images A collection device is proposed.

  According to the present invention, in the above apparatus, there is proposed an apparatus for collecting information by sound of a sedimentary layer under the water bottom, which has means for displaying the constructed three-dimensional acoustic image by alpha blending processing as the image construction means.

  In the present invention, in the apparatus, the acoustic measurement unit includes a transmitter and a plurality of receivers arranged in a ring around the transmitter, and the acoustic reflection of the plurality of receivers collected by the control device. We propose an information gathering device based on acoustics of the sedimentary layer beneath the bottom of the water, which is configured to perform processing to form sharp directivity by beam forming from signal data.

  According to the present invention, in the apparatus, the frame structure base has a rectangular parallelepiped configuration, and the XY drive mechanism forms a guide rail portion on an opposing frame member that is on the upper side when the frame structure base is in a bottomed state. An X-direction linear motion mechanism for driving a moving frame member installed between the opposing frame members by a rail portion; and a Y-direction linear motion mechanism for driving a support member of the acoustic measurement unit by a guide rail portion formed on the moving frame member; The information gathering device by the sound of the sedimentary layer under the bottom of the water is proposed in which the support member is configured to support the support case protruding from the acoustic measurement unit in the Z direction.

  According to the present invention, there is proposed an information gathering device based on the sound of the sedimentary layer below the water bottom surface, wherein the support member is provided with a drive mechanism for moving the support housing in the Z direction.

  In the above configuration, in the method and apparatus according to the present invention, the acoustic measurement signal is scanned in the XY direction by the XY drive mechanism and the data of the acoustic reflection signal is obtained in a state where the frame structure base is grounded on the water bottom by weight. Collect and thus collect information on the sediment layer beneath the bottom of the water.

  The collected information can be visualized on the display as an appropriate format, for example, a three-dimensional image, a tomographic image, etc., as in conventional sonar.

  When the acoustic measurement unit is scanned in the X and Y directions by the XY drive mechanism to collect information by sound, the frame structure base that supports the acoustic measurement unit is grounded on the water bottom by weight and has a frame structure. Therefore, the acoustic measurement unit is hardly affected by disturbance due to the frame structure base body because it is hardly affected by water flow or waves and maintains a stable stationary state. For this reason, the reproducibility of data by repeated measurement is high, and it is easy to monitor the change over time of the detection target.

  Since the XY drive mechanism itself can easily obtain very high positioning accuracy, the acoustic measurement unit can be scanned in the XY directions with very high accuracy.

  Furthermore, since the acoustic measurement unit forms a sharp directivity downward in the Z direction orthogonal to the XY direction, it collects information with very high resolution in combination with the high accuracy of scanning in the XY direction. be able to.

  The acoustic measurement unit may be configured to fix the position in the Z direction at a preset position, but if it can be moved in the Z direction, the position can be measured by moving the position. It can also be set at the time of measurement.

  The acoustic measurement unit shall reduce the beam width on the average over the entire circumference by forming sharp directivity by beam forming from the transmitter and a plurality of receivers arranged in a ring around the transmitter. As a result, higher resolution can be achieved.

  The frame structure base is formed in a rectangular parallelepiped shape, and the XY drive mechanism forms a guide rail portion on an opposing frame member that is on the upper side when the frame structure base is in a bottomed state, and the guide rail portion forms a space between the opposing frame members. The X direction linear motion mechanism that drives the moving frame member installed on the moving frame member, and the Y direction linear motion mechanism that drives the support member of the acoustic measurement unit by the guide rail portion formed on the moving frame member. The frame structure base and the XY drive mechanism can be configured by this frame structure, and as described above, it is possible to realize a configuration that is hardly affected by water flow or waves.

  In such a configuration, the support member of the acoustic measurement unit can be configured to support the support housing protruding from the acoustic measurement unit in the Z direction, and further drive to move the support housing in the Z direction. By providing the mechanism, it is possible to perform measurement by changing the position of the acoustic measurement unit in the Z direction.

  In the visualization of the collected information described above, the acoustic reflection signal data collected by scanning the acoustic measurement unit in the XY directions is processed to construct and construct C-mode plane images at multiple positions in the Z direction. A large number of C-mode plane images can be stacked to construct a three-dimensional acoustic image, and an image with very good visibility can be constructed by displaying the constructed three-dimensional acoustic image by alpha blending processing. be able to.

FIG. 1 is a perspective view schematically showing main elements of an information collecting apparatus according to the present invention. FIG. 2 is a side view schematically showing main elements of the information collecting apparatus according to the present invention. FIG. 3 is a plan view schematically showing main elements of the information collecting apparatus according to the present invention. FIG. 4 is a bottom view of the acoustic measurement unit according to the present invention. FIG. 5 shows the result of calculation of the beam pattern after beam forming in the configuration of the acoustic measurement unit of FIG. 4, and (a) shows the calculated value of the plane position 20 cm away from the transmitter, (b) shows the calculated value of the total directivity (product of the directivity of the transmitter and the receiver) of the transmitter and receiver at a plane position 1 m away from the transmitter. FIG. 6 shows a beam pattern after performing beam forming in the acoustic measurement unit according to the present invention. (A) shows the arrangement of the transmitter and receiver of the acoustic measurement unit, and (b) shows the Z direction. The observed beam pattern is shown. Fig. 7 shows the beam pattern of one transmitter and receiver in the acoustic measurement unit. (A) shows the arrangement of the transmitter and receiver in the acoustic measurement unit, and (b) shows the Z direction. The beam pattern is shown. FIG. 8 shows a beam pattern by one transmitter and two receivers arranged outside the acoustic measuring unit. (A) shows the arrangement of the transmitter and receiver of the acoustic measuring unit, (b) shows the beam pattern seen from the Z direction. FIG. 9 is an explanatory diagram showing a control configuration of the XY drive mechanism and the acoustic measurement unit according to the present invention. FIG. 10 is a flowchart showing an example of a process for displaying information on the sediment layer under the water bottom collected by the method and apparatus according to the present invention on a display. FIG. 11 shows an example of a three-dimensional image in which information on the sedimentary layer under the water bottom collected by the method and apparatus according to the present invention is displayed on a display.

  Hereinafter, embodiments of the present invention will be described in detail.

First, an example of an XY drive mechanism for moving the frame structure base and the acoustic measurement unit according to the present invention in the XY directions will be described with reference to FIGS.
Reference numeral 1 denotes a frame structure base according to the present invention, and FIGS. 1 to 3 correspond to a state in which the frame structure base 1 is bottomed on the water bottom. The frame structure base 1 is formed in a rectangular parallelepiped shape by a plurality of frame members 2, in this case, 12 frame members 2.

  In this embodiment, the guide rail portion 3x is formed on the opposing frame members 2a and 2b on the upper side when the frame structure base body 1 is in the bottomed state, and the guide rail portion 3x allows the gap between the opposing frame members 2a and 2b. The X direction linear motion mechanism which drives the moving frame member 4 installed in the frame is constituted.

The movable frame member 4 is configured to move and support the movable support members 5 provided at both ends along the guide rail portion 3 by an appropriate movable support mechanism, and the feed screw 6x for driving the motor 5x disposed along the frame member 2b. And the nut member 7x screwed to the feed screw 6x is driven in the X direction. Further, a guide rail portion 3 y is also formed on the movable frame member 4, and the support member 9 of the acoustic measurement unit 8 can be driven on the guide rail portion 3 y, and thereby the support member 9 can be moved to the movable frame member 4. A Y-direction linear motion mechanism that is driven along the XY drive mechanism is configured, and the XY drive mechanism of the support member 9 is configured by these. In this Y-direction linear motion mechanism, a feed screw 6 y for driving the motor 5 y is provided along the moving frame member 4, and a nut member 7 y that is screwed to the feed screw 6 y is provided on the support member 9.

  Reference numeral 8 denotes an acoustic measurement unit. The acoustic measurement unit 8 is provided with a pair of support housings 10 spaced apart on the upper side, and the support member 9 moves the support housing 10 up and down. That is, it is configured to be supported so as to be movable in the Z direction. At this time, the support member 9 has a semi-fixed configuration in which the fixing position of the support housing 10 can be adjusted, or a configuration in which the position of the acoustic measurement unit 8 can be changed in the Z direction by an appropriate motor driving mechanism. be able to.

  In this embodiment, the acoustic measurement unit 8 forms sharp directivity downward in the Z direction by beam forming. That is, in this embodiment, as shown in FIG. 4, the acoustic measurement unit 8 is configured to perform beam forming by arranging eight receivers 12 in an annular shape around the transmitter 11 on the center side. It is said.

  In this embodiment, by performing such beam forming, as shown in FIGS. 5 to 8, the beam width can be reduced on the average over the entire circumference, and good sharp directivity can be obtained. be able to.

  In addition, the acoustic measurement unit can form sharp directivity by appropriate beam forming or by mounting an acoustic lens.

  In the information collecting apparatus according to the present invention having the above-described configuration, the acoustic measurement unit 8 is moved in the XY direction by the XY drive mechanism in a state where the frame structure base 1 is grounded on the bottom surface of the sea, lake, or the like. To collect information on the sedimentary layer beneath the water bottom.

  When collecting information in this way, the frame structure base 1 that supports the acoustic measurement unit 8 is grounded on the bottom of the water due to its weight, and since it has a frame structure, it is not easily affected by water flow or waves. Since the stable stationary state is maintained, the acoustic measurement unit 8 is not affected by the disturbance by the frame structure base 1 at all.

  If the weight of the information collecting apparatus as a whole is too heavy, it may sink into the deposition layer below the bottom surface of the water, so it is necessary to set the weight in consideration of this.

  In the embodiment of the present invention, the frame structure base 1 is composed of an aluminum frame member 2, and a guide rail portion 3 x that is a component of the linear motion mechanism on one side of the XY drive mechanism is used as the frame member 2. Since the frame structure base and the XY drive mechanism are configured by the minimum necessary frame structure, a strong frame structure can be configured relatively lightly, and therefore, the bottom of the water bottom can be grounded. In this case, it can be prevented from sinking too much into the deposited layer under the water bottom.

  Thus, in the present invention, since the acoustic measurement unit 8 is not affected by the disturbance due to the frame structure base 1, and the XY drive mechanism itself can easily obtain very high positioning accuracy, the XY of the acoustic measurement unit 8 can be easily obtained. Directional scanning can be performed with very high accuracy, and in addition to the downward directivity in the Z direction, acoustic data in the sedimentary layer under the bottom of the water is collected with very high accuracy and high resolution. can do.

  As described above, the acoustic measurement unit 8 may be configured to fix the position in the Z direction to a preset position. However, if the acoustic measurement unit 8 is movable in the Z direction, the position can be measured by moving the position. An appropriate position can be set at the time of measurement.

  As described above, the data collected by the information collection device of the present invention can be displayed by the image display means configured in the collection device itself, or can be displayed by inputting the data to an image display device configured as a separate device. it can.

  FIG. 9 shows an embodiment of the control configuration of the XY drive mechanism and the acoustic measurement unit according to the present invention. In this configuration, the X-direction straight line constituting the XY drive mechanism is controlled by a control program using a notebook computer as a platform. The motor (stage motor (X), (Y)) of each of the moving mechanism and the Y-direction linearly moving mechanism is controlled via a motor driver, and one transmitter and eight receiving waves are received via a data acquisition program. The data is collected on the notebook computer through the data collecting means using the container. The data collected in the notebook personal computer is input to an image output device of another device and displayed. That is, in this embodiment, the control means for controlling the XY drive mechanism and the acoustic measurement unit 8 and collecting the data of the acoustic reflection signal by the acoustic measurement unit 8 is constituted by a notebook personal computer.

  FIG. 10 is a flowchart showing an example of a process for displaying the data of the sediment layer under the water bottom collected by the method and apparatus according to the present invention on the display of the image output apparatus. That is, this process corresponds to the above-described image construction means.

  First, step S1 is a data reading process. This process is performed by using a reflected signal of a sound wave (for example, a rectangular pulse) emitted from the transmitter 9 while moving the acoustic measurement unit 6 in the XY direction as described above. This is a process of receiving the data by the eight receivers 10 and reading the data of the reflected signal level of the sound waves collected and recorded in a predetermined range.

In the embodiment, a range of 80 (X direction) × 85 (Y direction) cm ² is scanned by an XY driving mechanism with positioning accuracy of ± 0.1 mm, and each of the positions of 6,966 (= 81 × 86) has 8 The data of the acoustic reflection signal level of each receiver 10 is collected and recorded. That is, the data recorded in this embodiment is composed of 6,966 files, each of which includes position data and data of the level of the 8ch acoustic reflection signal corresponding to the eight receivers 10. .

  Next, in step S2, beam forming processing is performed using 8ch acoustic reflection signals corresponding to the eight receivers 10, thereby achieving sharp directivity.

  Next, in step S3, an envelope detection process based on the Hilbert transform is performed. This process is a general process when imaging a sound wave with an ultrasonic diagnostic apparatus or the like, and only amplitude information is extracted by this process. By providing this process, the visibility of the displayed three-dimensional image can be improved.

  Next, in step S4, water bottom detection processing is performed. This process detects the boundary between the water and low mud (bottom surface), and specifically recognizes that the reflected signal level has exceeded a certain threshold for the first time.

  Next, in step S5, threshold processing is performed. This process is a general process in which weak noise components are removed by extracting only signal components that are above a certain threshold.

Next, in step S6, absorption attenuation amount correction processing is performed. This treatment is obtained by using the following equation assuming a simple linear model as the sound wave absorption attenuation α [dB / m] in the sediment layer under the bottom of the water.
Ad = Ai · exp (−αd)
(However, Ad is a signal level at a position d from the bottom surface, and Ai is a signal level at the bottom surface.)

  Next, in step S7, C-mode image generation processing is performed. In this process, for each distance d (depth) from the water bottom surface subjected to the absorption attenuation amount correction in step S6, the signal levels in the predetermined range are collected, and two-dimensional data for each distance d is constructed, This two-dimensional data corresponds to the two-dimensional tomographic image for each distance d. In the embodiment, 1,600 two-dimensional tomographic images are constructed.

  Next, in step S8, a three-dimensional image generation process is performed. In this process, the two-dimensional data for each distance d obtained in step 6 is arranged in the distance direction, that is, stacked to generate three-dimensional image data, which is stored.

  In the above processing flow, step S5 and step S6 can be reversed.

  Next, in step S9, alpha blend processing is performed. This process is generally performed as a drawing process in 3D image output, and by setting a count α (alpha value) corresponding to the transparency for each pixel of the 3D image data, Is used to construct a three-dimensional image.

As described above, the alpha blending process itself is general, but in the embodiment according to the present invention, the drawing process is performed from a point far from the viewpoint of the three-dimensional image, and in the drawing of the closer pixel, When there is an overlap with a pixel that has been drawn, a process for setting the luminance (lout) of a nearby pixel to be drawn is performed according to the following equation.
lout = lfront · α + lnow · (1-α)
(However, lout is the luminance of the nearby pixel to be rendered, lfront is the original luminance of the nearby pixel to be rendered, and lnow is the luminance of the pixel already rendered.)

By performing the above processing, in step S10, the three-dimensional acoustic data of the deposited layer in a predetermined range of the bottom of the water, for example, 80 (X direction) × 85 (Y direction) cm ² in the embodiment is highly accurate ( For example, accuracy is 0.1mm), high resolution, 3D beauty, and necessary information can be drawn intuitively. FIG. 11 shows an example of a three-dimensional image in which the information on the deposited layer is displayed on the display.

  In the image output process of step S10, when outputting to the image output device (display, printer, etc.) based on the 3D image data obtained in step S8, the image output is converted to 3D image data. Based on this, it is possible to appropriately perform 3D image output, 2D cross-sectional image output in the horizontal direction, vertical direction, and the like.

Since the present invention is as described above, various uses as described below can be performed, and industrial applicability is great.
1. Thickness measurement of sedimentary mud ... This can simplify the columnar coring.
2. 2. Management of root vegetables combined with agricultural IT technology. 3. Precise shape measurement of sunken ship covered with sedimentary mud 4. Precise shape measurement of weapons covered with sedimentary mud 5. Precise shape measurement of buried submarine cable Resource amount survey, resource management, ecological understanding of aquatic products inhabiting sedimentary mud

DESCRIPTION OF SYMBOLS 1 Frame structure base | substrate 2 (2a, 2b) Frame member 3x, 3y Guide rail part 4 Moving frame member 5x, 5y Motor 6x, 6y Feed screw 7x, 7y Nut member 8 Acoustic measuring part 9 Support member 10 Support housing 11 Transmitter 12 Receiver

Claims (12)

A plurality of frame members constitute a three-dimensional frame structure base that can be attached to the bottom of the water, and an acoustic measurement unit comprising a transmitter and a receiver is provided in the space of the frame structure base. The sound measurement unit has a sharp directivity downward in the Z direction perpendicular to the XY direction, while being supported by an XY drive mechanism that can move in the XY direction corresponding to the spreading direction of the bottom surface of the water bottom. In the state where the frame structure base is attached to the bottom of the water by weight, the acoustic measurement unit is scanned in the X and Y directions and the information of the deposited layer below the bottom of the water is collected from the data of the acoustic reflection signal. An information collection method using acoustics of a sedimentary layer below the bottom of water. The acoustic measurement unit forms a sharp directivity by beam forming from a transmitter and a plurality of receivers arranged in a ring around the transmitter, The sedimentary layer under the water bottom according to claim 1, Information collection method by sound. The acoustic reflection signal data collected by scanning the acoustic measurement unit in the X and Y directions is processed to construct C-mode plane images at a large number of positions in the Z direction. The method for collecting information by acoustic of the sediment layer under the water bottom according to claim 1, wherein an acoustic image is constructed. The information collection method according to claim 3, wherein the constructed three-dimensional acoustic image is displayed after alpha blending. The frame structure base has a rectangular parallelepiped structure, and the XY drive mechanism lays a moving frame member that supports the acoustic measurement unit so as to be movable between the opposed frame members on the upper side in the bottomed state. 5. The information collecting method by acoustic of a sedimentary layer under a water bottom according to any one of claims 1 to 4, wherein the information is movable along the opposing frame members. 6. The method for collecting information by acoustic of a sedimentary layer under a water bottom according to claim 1, wherein the acoustic measurement unit is supported so as to be movable in the Z direction. A three-dimensional frame structure base composed of a plurality of frame members and capable of bottoming on the bottom of the water, an acoustic measurement unit comprising a transmitter and a receiver, and the acoustic measurement unit. The XY drive mechanism that is movably supported in the XY direction corresponding to the spreading direction of the water bottom surface in the finished state, the XY drive mechanism and the acoustic measurement unit are controlled, and the acoustic reflection signal data is collected by the acoustic measurement unit An information collecting apparatus using acoustics of a sedimentary layer under a water bottom, comprising control means, wherein the acoustic measuring unit has a directivity formed downward in a Z direction orthogonal to the XY direction. Image construction means for constructing a three-dimensional acoustic image from the collected acoustic reflection signal data is provided. The image construction means processes the collected acoustic reflection signal data to obtain C-modes at multiple positions in the Z direction. The means for constructing a planar image, and means for constructing a three-dimensional acoustic image by stacking a large number of constructed C-mode planar images, Information collection device by sound. 9. The information collecting apparatus according to claim 8, wherein the image construction means includes means for displaying the constructed three-dimensional acoustic image by performing an alpha blend process. The acoustic measurement unit is composed of a transmitter and a plurality of receivers arranged in a ring around the transmitter, and is sharply directed by beamforming from the acoustic reflection signal data of the plurality of receivers collected by the control device. The apparatus for collecting information by acoustic of the sedimentary layer under the water bottom according to claim 7 or 8, wherein the processing for forming the property is performed. The frame structure base has a rectangular parallelepiped configuration, and the XY drive mechanism forms a guide rail portion on an opposing frame member that is on the upper side when the frame structure base is in a bottomed state, and the guide rail portion forms a space between the opposing frame members. An X-direction linear motion mechanism that drives a moving frame member installed on the moving frame member, and a Y-direction linear motion mechanism that drives a support member of the acoustic measurement unit by a guide rail portion formed on the moving frame member. The information collecting apparatus according to any one of claims 7 to 9, characterized in that the support case protruding from the acoustic measurement unit is supported in the Z direction. The information collecting apparatus according to claim 10, wherein the support member is provided with a drive mechanism for moving the support housing in the Z direction.