JPS6273186A - Apparatus for discriminating geology of sea bottom - Google Patents

Abstract

PURPOSE:To quantitatively discriminate the geology of a sea bottom to easily perform continuous investigation over a wide range, by analyzing slide friction sound generated when a sliding sound emitter moves and slides on the geology of the sea bottom. CONSTITUTION:The slide friction sound generated by a sliding sound emitter 1 is sensed by a sonic wave sensor 2 to be converted to an electric signal which is, in turn, transmitted to a signal analyser 4 by a transmission means 3. A wire system using a cable or a wireless system using a carrying ultrasonic wave is used as the transmission means 3. The apparatus 4 performs the analysis of the frequency spectrum, wave form and sound pressure level, etc. of the signal inputted through the transmission means and compares the analytical results with the various characteristics inherent to the geology of the sea bottom to accurately judge the same. By this method, the geology of the sea bottom is discriminated and continuous investigation over a wide range is easily performed.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applicable to fish habitat surveys, sea sand collection site surveys,
Geology of the seabed (seafloor sediment) necessary for preliminary surveys of underwater construction, etc.
The present invention relates to a device for determining.

(Prior Art and Problems) Conventionally, as methods for investigating the bottom sediments of the seabed, there have been methods using a sediment collector or polling, methods using an acoustic strata exploration device, and the like. However, as is well known, the method using a mud sampler or polling is a point survey in which mud, sand, gravel, etc. from the seabed are collected and surveyed one by one at each survey point, and therefore the survey vessel must be stopped at each survey point. Therefore, since each survey point requires time and effort, it is not possible to collect a large number of survey points with limited time and money, and it is difficult to carry out detailed surveys over a wide area. The problem was that it required a lot of time and money.

In addition, the method using an acoustic geological exploration device is a method that uses the shading and pattern of the seafloor record image that appears on the recording paper of the recorder as clues while moving the research vessel. Judgments were often made based on experience and intuition rather than quantitative ones. Therefore, there was a problem that judgments differed depending on the observer.In consideration of the above-mentioned problems of the conventional technology, the purpose of the present invention is to conduct a quantitative investigation of seafloor sediment over a wide range of areas at lower cost and in a shorter time than before. The purpose is to provide a seafloor sediment determination device that can continuously perform the determination over a long period of time.

(Means for solving problems) The present invention has the following configuration to achieve the above object.

That is, the submarine bottom sediment determination device of the present invention includes a rubbing sounding body that rubs the seabed, a sonic sensor that detects the rubbing sound generated by the rubbing sounding body, and a sound wave signal sensed by the sonic sensor. The present invention is characterized in that it includes a signal analysis means for analyzing a signal, and a transmission means for transmitting a sound wave signal generated by the sound wave sensor to the signal analysis means. FIG. 1 is a block diagram showing the configuration of the submarine sediment discriminating device of the present invention. 1 is a rubbing sounding body, 2
is a sound wave sensor, 3 is a transmission means, and 4 is a signal analyzer.

(Function) Hereinafter, the function of the device of the present invention will be explained based on the drawings. The rubbing sounding body 1 is located on the ocean floor and is connected to a research vessel using a rope or the like, and is dragged along the ocean floor by the movement of the research vessel. At this time, rubbing noise is generated by the friction with the seabed. The frequency spectrum and waveform of this rubbing sound vary greatly depending on whether the geology of the ocean floor is clay, mud, sand, or gravel. Furthermore, even in the case of sand, there are differences in frequency spectrum, sound pressure level, etc. depending on the size of the particles.

As described above, the submarine bottom sediment determination device of the present invention focuses on the fact that the frequency spectrum and other characteristics of the rubbing sound differ depending on the geology of the seabed, and analyzes this rubbing sound2. This is an attempt to identify seafloor sediment.

Therefore, the rubbing sound generated by the rubbing sounding body 1 is detected by the sonic sensor 2, converted into an electrical signal, and then sent to the signal analysis device 4 by the transmission means 3. Sonic sensor 2
1 is set at a level where the rubbing noise can be sufficiently detected, and its frequency band characteristics are set so as to be able to sufficiently distinguish differences due to the bottom sediment of the ocean floor.

Further, the transmission means 3 may be a wired system using a cable, or a wireless system using ultrasonic waves for conveyance.

The No. 18 analyzer 4 analyzes the frequency spectrum, waveform, sound pressure level, etc. of the signal input through the transmission means, and compares it with the unique characteristics of various seabed sediments to determine what kind of seafloor sediment it is. accurately judge whether In this way, the seabed sediment determination method using the device of the present invention can be carried out continuously while the research vessel is moving, so unlike spot surveys using a mud sampler or polling, it is possible to conduct continuous surveys over a wide area. Investigations can be conducted easily. In addition, since the determination is based on a quantitative analysis method rather than on the researcher's experience or intuition, accurate determination results can be obtained.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. The propagation path of the rubbing noise generated by the rubbing sounding body is that it propagates through the towed sounding body structure, and it radiates into the sea.9 Both include noise caused by the undulation of the seabed and ship noise Each type of sound wave sensor has its own specificity depending on how it is influenced by the sound waves, so there are differences in the type of sound wave sensor and the mounting structure, but there is no difference in the principle of the present invention between the two. Therefore, the embodiment will be explained based on the drawings for the case of underwater propagation. . FIG. 2 is a diagram showing the configuration of the embodiment device and the usage status of the device.

1 is a sliding sounding body, and 2' is a towed sounding body structure 1 so that it is easy to detect the sliding sound with an underwater microphone serving as a sonic sensor.
It is attached to 1. 3' is a cable as a transmission means. Reference numeral 7 is an amplifier, 5 is a frequency analyzer, and 6 is a recorder, and these three components constitute a signal analysis device, which is normally mounted on the research vessel 8. 9 is a lobe for dragging the rubbing sounding body, and 10 is the seabed.

As the sliding sounding body, there are those whose sliding surface is in the shape of a file as shown in FIG. 3, and those whose sliding surface is curved as shown in FIG. 4. Figure 5 shows the frequency analysis data of the rubbing sound of each seabed geology obtained in a water tank experiment using a file-like rubbing sounding body. FIG. 6 shows frequency analysis data when a curvature-like sliding sounding body is also used. Fifth
Looking at Figure 6 and Figure 6, there are not many differences due to differences in sounding bodies, but in both figures, the frequency spectra of clay, mud, sand, and gravel each have their own characteristics and show significant differences. Even in the case of sand, the sound pressure level varies depending on the particle size, and there is a tendency for the sound pressure to increase as the particle size increases.

In this way, there are characteristic differences in the frequency spectrum of rubbing sounds depending on the geology of the ocean floor, so if you collect actual measurement data to understand the characteristics of each geology and store it in a storage device, you can easily investigate it later. By analyzing the observed rubbing sounds and comparing them with stored data, it is possible to accurately determine the geology.

In this embodiment, we have mainly focused on the frequency spare 1 to ram of the rubbing sound, but various other analyzes such as an analysis focusing on the waveform of the sound wave or an analysis focusing on changes in the sound pressure level can be considered. It will be done.

(Effects of the Invention) As explained above, the device of the present invention focuses on the fact that the rubbing sound emitted when the rubbing sounding body moves and rubs on the seabed geology has different characteristics depending on the type of seabed geology. This is a device that attempts to quantitatively determine the geology of the ocean floor by analyzing this rubbing sound. The sliding sounding body can be easily moved by connecting a lobe to the towed sounding body structure to which the sounding body is attached and dragging it around by a research vessel.Furthermore, the sliding sound can also be detected by using the towed sounding body structure. This can be easily done with a sonic sensor attached to a body structure. Therefore, the device of the present invention is capable of analytical and quantitative investigation without relying on empirical elements, unlike methods using conventional acoustic strata exploration devices, and is capable of conducting point investigations using conventional soil sampling equipment or polling. In comparison, it has the advantage of being able to conduct continuous surveys over a much wider area in a shorter period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the device of the present invention, FIG. 2 is an explanatory diagram of the configuration of the device according to the embodiment of the present invention and the state of use of the device, FIG. 3 is a perspective view of the file-like rubbing surface, and FIG. The figure is a perspective view of a warped rubbing surface, FIG. 5 is a diagram showing experimental data on a water tank using a file-like sounding body, and FIG. 6 is a diagram showing experimental data on a water tank using a warped sounding body. 1...Sliding sounding body, 2...Sound wave sensor, 2'...Underwater microphone (sound wave sensor)
3...Transmission means, 3'...Cable, 4...Signal analyzer, 5...Frequency analyzer, 6...Recorder , 7...
Amplifier, 8... Research vessel, 9... Rope, 10... Seabed, 11... Towed sounding body structure. Agent Patent Attorney Yoshi Hachiman Hiroshi Hakuhoki 1's 11 Wei$ / Figure 4 Yugo Analysis 11 The structure and theory of Kyouzume Gao's brother Figure 2

Claims (1)

[Claims] A rubbing sounding body that rubs the seabed, a sonic sensor that detects the rubbing sound generated by the rubbing sounding body, a signal analysis means that analyzes a soundwave signal detected by the sonic sensor, and the soundwave sensor A seafloor sediment discrimination device characterized by comprising a transmission means for transmitting a generated sound wave signal to the signal analysis means.