JP2008076294A - Under-bottom-of-water survey method and instrument - Google Patents

Under-bottom-of-water survey method and instrument Download PDF

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JP2008076294A
JP2008076294A JP2006257408A JP2006257408A JP2008076294A JP 2008076294 A JP2008076294 A JP 2008076294A JP 2006257408 A JP2006257408 A JP 2006257408A JP 2006257408 A JP2006257408 A JP 2006257408A JP 2008076294 A JP2008076294 A JP 2008076294A
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water
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water area
waves
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Koichiro Tanaka
浩一郎 田中
Shinichi Sawada
信一 澤田
Hiroshi Sudo
拓 須藤
Takahiro Fukai
隆広 深井
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IHI Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an under-bottom-of-water survey method and instrument, which reduces omission in survey. <P>SOLUTION: In this under-bottom-of-water survey method of mounting an echo sounder transmitter 2 for transmitting a sound wave into water, and an echo sounder receiver 4 for receiving a scattered wave from an object 3, on an underwater navigation body 5, and for surveying an object under the bottom of the water within a prescribed water area Ea, while circulation-navigating the underwater navigation body 5 around the water area, an underwater background noise and reverberation sound are measured preliminarily, the water area is set narrow when the background noise and reverberation sound are high, the water area is set wide when the background noise and reverberation sound are low, and the survey is carried out in the periphery of the set water area, by the circulation-navigation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、低コストで探査漏れを少なくできる水底下探査方法及び装置に関する。   The present invention relates to a submarine exploration method and apparatus that can reduce exploration leakage at low cost.

遺跡・遺物や器具・機械などの人工物からなる水没品の探査は音響探査で行われる。このような音響による水底下探査においては、対象の物体が水底下に埋没していることが多い。ここで、水底下という用語の定義は、特許文献１と同様であり、水面から水底までを水中、砂、泥、礫等の固体部分の表面（音波に対して音響的な境界を形成する面）を水底、その固体部分の内部を水底下と言う。   The exploration of submerged items made up of artifacts such as ruins, artifacts, instruments and machines is performed by acoustic exploration. In such underwater exploration using acoustics, the target object is often buried under the bottom of the water. Here, the definition of the term “under the bottom of the water” is the same as that of Patent Document 1, and the surface of the solid part such as water, sand, mud, gravel, etc. from the water surface to the bottom of the water (surface that forms an acoustic boundary with the sound wave ) Is called the bottom of the water, and the inside of the solid part is called the bottom of the bottom.

埋没している物体を探査するためには、水底下にある物体からの散乱波を捉える必要がある。水底下では音波の減衰が大きいため、水底下にある物体からの散乱波は水中や水底や水面上にある物体からの散乱波よりもさらに微弱なものとなり、この微弱な信号を計測する必要がある。   In order to explore the buried object, it is necessary to capture the scattered wave from the object under the bottom of the water. Since the sound wave attenuation is large under the water bottom, the scattered wave from the object under the water bottom becomes even weaker than the scattered wave from underwater, the water bottom or the object on the water surface, and it is necessary to measure this weak signal. is there.

また、水底に凹凸などがある場合には、それにより不必要な散乱波（水底散乱波）が発生し、この水底散乱波の受波レベルが物体からの散乱波の受波レベルよりも高くなると妨害になり探査ができなくなる。この水底散乱波のレベルは散乱波を発生する水底領域の面積に比例して大きくなるため、この面積が狭いほうが水底散乱波の影響を低減できる。そのため、水底下物体を探査するためには散乱波を発生する水底領域の面積を所定の範囲以下に絞った計測が必要となる。この水底領域の面積を絞るための方法として、送波で狭い指向性のものを使う、受波で狭い指向性のものを使う、またその組み合わせを使う方法がある。高周波では水底での反射や水底下での減衰が大きくなるため、低周波を用いる必要があるが、小型の装置により狭い指向性を実現するのは難しいという課題点がある。   In addition, if there are irregularities on the bottom of the water, an unnecessary scattered wave (bottom scattered wave) is generated, and the received level of the scattered water is higher than the received level of the scattered wave from the object. It becomes obstructed and cannot be explored. Since the level of the water bottom scattered wave increases in proportion to the area of the water bottom region where the scattered wave is generated, the influence of the water bottom scattered wave can be reduced when the area is smaller. For this reason, in order to search for an object under the bottom of the water, it is necessary to make a measurement in which the area of the water bottom region where the scattered wave is generated is reduced to a predetermined range or less. As a method for narrowing down the area of the water bottom region, there are a method using a narrow directivity for transmission, a method using a narrow directivity for reception, and a combination thereof. Since reflection at the bottom of the water and attenuation under the bottom of the water increase at high frequencies, it is necessary to use a low frequency, but there is a problem that it is difficult to achieve narrow directivity with a small device.

さらに、物体にはその形状や性質に応じて特定の向きに音波を散乱させる性質がある。例えば、図８（ａ）〜図８（ｄ）は、物体３が円筒体の場合であって、ある高度の水平面における散乱波のレベル分布を模式的に示したものである。すなわち、円筒体からなる物体３に対してある角度から送波すると、物体３の周囲には散乱波の音圧が高い部分、中の部分、低い部分が生じ、それ以外の部分はさらに音圧が低い。これらの図のように、散乱波のレベルの高い範囲は限定され、物体を探査するためにこの狭い範囲内で散乱波を捉える必要がある。   Furthermore, an object has a property of scattering sound waves in a specific direction according to its shape and properties. For example, FIGS. 8A to 8D show a case where the object 3 is a cylindrical body, and schematically shows the level distribution of scattered waves on a certain level of horizontal plane. That is, when a wave is transmitted from a certain angle with respect to the object 3 formed of a cylindrical body, a portion where the sound pressure of the scattered wave is high, a middle portion, and a low portion are generated around the object 3, and the other portions further have a sound pressure. Is low. As shown in these figures, the range where the level of the scattered wave is high is limited, and it is necessary to capture the scattered wave within this narrow range in order to search for an object.

水没品の音響探査に有利な方法・装置として、（あ）パラメトリックソーナー＋合成開口処理によるもの、（い）複数水中航行体を用いるものなどが提案されているが実用化されていない。   As methods and devices advantageous for acoustic exploration of submerged items, (a) parametric sonar + synthetic aperture processing, (ii) using multiple underwater vehicles, etc. have been proposed but not put into practical use.

（あ）のパラメトリックソーナーは、送波で狭い指向性のものを使う方法である。パラメトリックソーナーとは、送波器を比較的高い近接した２つの周波数（例えば１０３ｋＨＺと１００ｋＨＺ）で大振幅駆動させ、媒質の非線形相互作用により、その差音である低周波（この場合３ｋＨｚ）が生じるようにすることにより、低周波音でありながら、指向性が強い送波が可能となるものである。パラメトリックソーナーから強い指向性の低周波、つまり広がる角度が狭い低周波を送波するので、散乱波の発生場所を限られた範囲に絞ることができる。また、合成開口処理は、受波で狭い指向性のものを使う方法である。合成開口処理とは、受波器の物理的な開口を越える大きさの仮想的開口を例えば水中航行体などが移動しながら散乱波を受波することにより実現する方法である。合成開口処理によって、より大きな開口を作るので合成前の受波器で得られる指向性と比べ、より鋭い指向性が得られる。そのため、限られた範囲からの散乱波だけを検出することができる。従って、パラメトリックソーナーと合成開口処理とを組み合われると、低周波による水底下探査が可能である。   The (a) parametric sonar is a method of using a narrow directivity for transmission. In the parametric sonar, a transmitter is driven with a large amplitude at two relatively close frequencies (for example, 103 kHz and 100 kHz), and a low frequency (in this case, 3 kHz) is generated due to the nonlinear interaction of the medium. By doing so, it is possible to transmit a wave having a strong directivity while being a low frequency sound. Since the parametric sonar transmits a low frequency with strong directivity, that is, a low frequency with a narrow spread angle, the location where the scattered wave is generated can be limited to a limited range. Synthetic aperture processing is a method of using a received wave having a narrow directivity. The synthetic aperture processing is a method for realizing a virtual aperture having a size exceeding the physical aperture of the receiver by receiving a scattered wave while an underwater vehicle or the like moves. Since a larger aperture is created by the synthetic aperture processing, sharper directivity can be obtained as compared with the directivity obtained by the receiver before synthesis. Therefore, only scattered waves from a limited range can be detected. Therefore, when the parametric sonar and the synthetic aperture processing are combined, it is possible to search the bottom of the water bottom at a low frequency.

（い）は、特許文献１に記載されたものであり、低周波の送波器を搭載して水中を移動する親機と、受波器を搭載して水中を移動する複数の子機とを使用し、複数箇所で受波した物体からの散乱波を探査する。この方式の利点の一つとして、物体の形状等に基づく散乱特性において、特定の方向に強く散乱が起きるような場合に、複数の子機が物体の周囲の各方角を通過するので、散乱の強い方向で受波する機会が増やせることがあげられる。   (Ii) is described in Patent Document 1, and a parent device that moves underwater with a low-frequency transmitter, and a plurality of child devices that move underwater with a receiver To search for scattered waves from objects received at multiple locations. One advantage of this method is that when the scattering characteristics based on the shape of the object, etc., cause strong scattering in a specific direction, multiple slave units pass through each direction around the object. The opportunity to receive waves in a strong direction can be increased.

特開２００４−１８４２６８号公報JP 2004-184268 A 佐藤 潤・斉藤 正徳、１９８７、Ｇｏｐｉｎａｔｈ−Ｓｏｎｄｈｉ積分方程式を用いた反射データのインバージョン、物理探査学会春季講演会Jun Sato, Masanori Saito, 1987, Inversion of reflection data using Gopinath-Sondhi integral equation, Spring Meeting of the Geophysical Exploration Society of Japan Ｍｏｕｒａｄ．Ｐ．Ｄ．ａｎｄ Ｊａｃｋｓｏｎ．Ｄ．Ｒ．（１９８９）“Ｈｉｇｈｆｒｅｑｕｅｎｃｙ ｓｏｎａｒ ｅｑｕａｔｉｏｎ ｍｏｄｅｌｓ ｆｏｒ ｂｏｔｔｏｍ ｂａｃｋｓｃａｔｔｅｒ ａｎｄ ｆｏｒｗａｒｄ ｌｏｓｓ” ｉｎ Ｐｒｏｃｅｅｄｉｎｇｓ ｏｆ ＯＣＥＡＮＳ’８９（ＩＥＥＥ Ｎｅｗ Ｙｏｒｋ）．ｐｐ．１１６８−１１７５Mourad. P. D. and Jackson. D. R. (1989) “High frequency sonar equation models for bottom backscatter and forward loss” in Proceedings of OCEANS'89 (IEEE New York). pp. 1168-1175

パラメトリックソーナーは、その装置自体のサイズが例えば、１ｍ角と大きく重量も重い。このため、パラメトリックソーナーを搭載して航行する水中航行体は、大型となる。水中航行体を船舶などに搭載して運用する場合には、その搭載スペースが限られるため大型なものは好ましくない。水中航行体のエネルギ源はバッテリであるが、パラメトリックソーナーが大音圧の差音を利用していることからエネルギ効率が低い。また、水中航行体が大型であることから、バッテリにも大容量が要求され、バッテリも大型化する。従って、（あ）の方式は、水中航行体の大型化とコスト高に問題がある。   A parametric sonar has a large size and a heavy weight of, for example, 1 m square. For this reason, the underwater navigation body which carries a parametric sonar and sails becomes large. When the underwater navigation body is mounted and operated on a ship or the like, a large-sized one is not preferable because its mounting space is limited. The energy source of the underwater vehicle is a battery, but the energy efficiency is low because a parametric sonar utilizes a differential sound of high sound pressure. Further, since the underwater vehicle is large, the battery is also required to have a large capacity, and the battery is also large. Therefore, the method (a) has problems in increasing the size and cost of the underwater vehicle.

また、（あ）の方式は、送波も受波も指向性が鋭いため、物体に音波が当たる機会が少なく、物体からの散乱波が生じる機会が少なく、物体を見逃すことがある。   In addition, the method (a) has a sharp directivity for both transmission and reception, so there are few opportunities for the sound wave to hit the object, there are few opportunities for the scattered wave to be generated from the object, and the object may be missed.

一方、（い）の方式は、複数の水中航行体を制御するのでシステムが複雑化すると共に、水中航行体が複数必要なことでコスト高となる。   On the other hand, the method (ii) controls a plurality of underwater vehicles, complicating the system, and requires a plurality of underwater vehicles, resulting in high costs.

水中航行体を１台だけ使用して送波も受波もその水中航行体で行うことができれば、もしくは少ない機数の水中航行体を使用して探査ができれば、コストを下げられる。しかし、物体が極端に偏った散乱指向性を有する場合に、水中航行体を１台だけもしくは少ない機数の水中航行体を使用して漏れなく物体を発見できるようにするには、何らかの工夫が必要である。つまり、コストの問題と探査漏れの問題を両立させて解決する必要がある。   The cost can be reduced if only one underwater vehicle is used to transmit and receive waves and the underwater vehicle can be used for exploration. However, if the object has extremely biased scattering directivity, there will be some ingenuity in order to be able to find the object without leakage using only one underwater vehicle or a small number of underwater vehicles. is necessary. In other words, it is necessary to solve both the problem of cost and the problem of missing search.

ここで、物体の探査漏れが生じる要因について考察する。   Here, let us consider the factors that cause object leakage.

送受波を行うとき、実際には、送波器からの音波が物体で散乱した散乱波だけが都合良く受波されるのではなく、水中航行体のモータ音、舵の音などの自己雑音と、波や海洋生物より発生する雑音、周囲を航行する船舶が出す雑音などの周囲雑音とが重畳されて受波される。これら自己雑音と周囲雑音とを併せて背景雑音と呼ぶ。物体の探査を行うには背景雑音よりも高いレベルの物体からの散乱波を受波しなければならない。仮に物体からの散乱波が小さくても背景雑音がそれより十分に小さければ物体の探査が可能であるのに対し、物体からの散乱波が大きくても背景雑音が同様に大きければ物体の探査が不可能あるいは困難である。   When transmitting and receiving waves, in fact, not only scattered waves in which the sound waves from the transmitter are scattered by the object are conveniently received, but self-noise such as motor sounds and rudder sounds of underwater vehicles. Ambient noise such as noise generated from waves and marine organisms and noise generated by ships navigating the surroundings are superimposed and received. These self noise and ambient noise are collectively referred to as background noise. In order to search for an object, it is necessary to receive a scattered wave from an object whose level is higher than the background noise. Even if the scattered wave from the object is small, the object can be searched if the background noise is sufficiently smaller than that. On the other hand, if the scattered noise from the object is large, the object can be searched if the background noise is also large. Impossible or difficult.

また、上記した背景雑音のほかに水底や水面からの残響音がある。残響音は送波器より音波を送波したことによって生じるので、背景雑音と違って送波器のレベルを高くするだけでは回避することができない。さらに、水底下では、水底中での音のレベル減衰や音波の曲がりといった音響特性があり、水底下の物体を漏れなく探査するためには、これらの音響特性をあらかじめ知った上で、その音響特性を利用した探査をする必要がある。   In addition to the background noise described above, there are reverberation sounds from the bottom of the water and the water surface. Since reverberant sound is generated by transmitting a sound wave from a transmitter, unlike background noise, it cannot be avoided simply by increasing the level of the transmitter. In addition, there are acoustic characteristics such as sound level attenuation and sound wave bending in the bottom of the water. Exploration using characteristics is necessary.

また、水中では、水温や不純物濃度（特に海域では塩分濃度）によって音速が異なる。音速が異なると距離計測に影響すると共に、水温や不純物濃度が場所によって異なる分布をしていると、音速の分布が不均一になり、音波の曲がりが生じる。このことも物体の探査漏れの要因となる。   In water, the speed of sound varies depending on the water temperature and impurity concentration (especially salt concentration in the sea area). If the sound speed is different, distance measurement is affected, and if the water temperature and the impurity concentration are distributed differently depending on the location, the sound speed distribution becomes non-uniform and the sound wave is bent. This is also a factor in the object exploration leak.

また、水底には、水流などによりできた凹凸がある場合がある。この凹凸で音波が散乱すると、水底下に音波が浸透しにくくなると共に、凹凸からの散乱波が探査の妨害になる。また、この凹凸の間隔や高さにより、水底下に浸透しやすい（凹凸で散乱しにくい）周波数が異なる。   In addition, the bottom of the water may have irregularities formed by a water flow or the like. When sound waves are scattered by the unevenness, it becomes difficult for the sound waves to penetrate under the water bottom, and the scattered waves from the unevenness hinder the exploration. Moreover, the frequency at which it easily permeates under the water bottom (difficult to scatter due to unevenness) varies depending on the interval and height of the unevenness.

さらに、（い）の方式において、親機及び子機を周回航行させてその周回領域内のあらゆる角度から散乱波をしようとするとき、周回の径を小さくすると、狭い領域しか探索できず、効率が良くない。逆に、周回の径を大きくすると、送波した音波が散乱して受波器に戻るまでの距離が延び、音波の減衰による音圧の低下が避けられない。従って、前述した背景雑音や残響音が大きいとき、周回の径を大きくするのは好ましくない。このように、周回の径を適切に決められるかどうかも、探査漏れの発生に深く関わる事柄である。   Furthermore, in the method (ii), when the main unit and the sub unit are cruising around and trying to scatter waves from any angle within the lap region, if the lap diameter is reduced, only a narrow region can be searched for efficiency. Is not good. On the other hand, when the diameter of the circuit is increased, the distance until the transmitted sound wave is scattered and returned to the receiver is extended, and a decrease in sound pressure due to attenuation of the sound wave is inevitable. Therefore, it is not preferable to increase the diameter of the circuit when the above-described background noise or reverberation sound is large. As described above, whether or not the diameter of the lap can be appropriately determined is also a matter deeply related to occurrence of an exploration leak.

そこで、本発明の目的は、上記課題を解決し、低コストで探査漏れを少なくできる水底下探査方法及び装置を提供することにある。   Accordingly, an object of the present invention is to provide a submarine exploration method and apparatus that can solve the above-described problems and can reduce exploration leakage at low cost.

上記目的を達成するために第１の発明による水底下探査方法は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査方法において、あらかじめ水中の背景雑音や残響音を計測し、この背景雑音や残響音が大きいときには上記水域を狭く設定し、上記背景雑音や残響音が小さいときには上記水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うものである。   In order to achieve the above-described object, the underwater survey method according to the first invention includes a transmitter for transmitting a sound wave in water and a receiver for receiving a scattered wave from an object mounted on the underwater vehicle. In the submarine exploration method for exploring an object under the water bottom in the water area while navigating the underwater vehicle around the predetermined water area, the background noise and reverberation sound in the water are measured in advance. When the reverberant sound is high, the water area is set narrow, and when the background noise or reverberant sound is low, the water area is set wide, and the search is performed around the set water area by the circular navigation.

第２の発明による水底下探査方法は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査方法において、あらかじめ水底の音響特性パラメータ（音速、密度、減衰係数）を計測し、この音響特性パラメータを用いた音波伝搬解析を行い、上記水底が音波を伝えにくいときには上記水域を狭く設定し、上記水底が音波を伝えやすいときには上記水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うものである。   A submarine exploration method according to a second aspect of the present invention includes a transmitter that transmits sound waves in water and a receiver that receives scattered waves from an object mounted on the underwater vehicle, and the underwater vehicle is set in a predetermined manner. In the submarine exploration method of exploring objects under the bottom of the water area while navigating around the water area, the acoustic characteristic parameters (sound speed, density, attenuation coefficient) of the bottom of the water are measured in advance. When the water bottom is difficult to transmit sound waves, the water area is set to be narrow, and when the water bottom is easy to transmit sound waves, the water area is set to be wide, and around the set water area, It is for exploration.

上記音響特性パラメータは、上記送波器から試験波を送波して水底で反射した音波を上記受波器で受波し、受波した信号を用い逆問題解析計算により求めてもよい。   The acoustic characteristic parameter may be obtained by inverse problem analysis calculation using a signal obtained by transmitting a test wave from the transmitter and receiving a sound wave reflected from the bottom of the water with the receiver.

第３の発明による水底下探査方法は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を航行させつつ水底下にある物体を探査する水底下探査方法において、あらかじめ水底の凹凸を計測し、その凹凸を入力値にした音波伝搬解析を行い、水底下に音波を伝えにくいときには上記水域を狭く設定し、水底下に音波が伝えやすいときには水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うものである。   A submarine exploration method according to a third aspect of the present invention includes a transmitter that transmits sound waves in water and a receiver that receives scattered waves from an object on an underwater vehicle, and navigates the underwater vehicle. In the submarine exploration method for exploring objects under the bottom of the water, the unevenness of the bottom of the water is measured in advance, and the sound wave propagation analysis is performed using the unevenness as an input value. However, when sound waves can be easily transmitted under the water bottom, the water area is set wide, and the search is performed around the set water area by the above-mentioned circular navigation.

凹凸に応じて音波が伝わりやすい周波数を用いてもよい。   A frequency at which sound waves are easily transmitted according to the unevenness may be used.

また、第１の発明による水底下探査装置は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器と、これら送波器及び受波器を搭載する水中航行体とを備え、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査装置において、あらかじめ水中の背景雑音や残響音を計測する背景雑音計測器と、この背景雑音や残響音が大きいときには上記水域を狭く設定し、上記背景雑音や残響音が小さいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行うものである。   Moreover, the underwater survey device according to the first invention is equipped with a transmitter for transmitting a sound wave into water, a receiver for receiving a scattered wave from an object, and these transmitter and receiver. A submarine exploration device that explores objects under the bottom of the water body while navigating the underwater navigation body around a predetermined body of water, and measures underwater background noise and reverberation sound in advance. And a water area setting means for setting the water area narrow when the background noise and reverberation sound are large, and setting the water area wide when the background noise and reverberation sound are small. The above-mentioned orbital exploration is performed around the.

第２の発明による水底下探査装置は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器と、これら送波器及び受波器を搭載する水中航行体とを備え、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査装置において、あらかじめ水底の音響特性パラメータ（音速、密度、減衰係数）を計測する音響特性パラメータ計測器と、この音響特性パラメータを用いた音波伝搬解析を行う音波伝搬解析手段と、水底が音波を伝えにくいときには上記水域を狭く設定し、水底が音波を伝えやすいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行ううものである。   A submarine exploration device according to a second invention includes a transmitter for transmitting a sound wave in water, a receiver for receiving a scattered wave from an object, and underwater navigation in which these transmitter and receiver are mounted. A submarine exploration device for exploring an object under the water bottom in the water area while navigating the underwater navigation body around a predetermined water area, in advance, the acoustic characteristic parameters (sound speed, density, attenuation) of the water bottom Acoustic characteristic parameter measuring instrument that measures the coefficient), sound wave propagation analysis means for performing sound wave propagation analysis using this acoustic characteristic parameter, and when the water bottom is difficult to transmit sound waves, the water area is set narrow, and the water bottom is easy to transmit sound waves In some cases, a water area setting means for setting the water area broadly is provided, and an exploration by the round navigation is performed around the set water area.

上記音響特性パラメータ計測器は、上記送波器から試験波を送波して水底で反射した音波を上記受波器で受波する試験手段と、受波した信号を用い逆問題解析計算により音響特性パラメータを推定する音響特性パラメータ推定手段とを有してもよい。   The acoustic characteristic parameter measuring device includes a test means for transmitting a test wave from the transmitter and receiving a sound wave reflected from the bottom of the water by the receiver, and an acoustic analysis by inverse problem analysis calculation using the received signal. You may have an acoustic characteristic parameter estimation means to estimate a characteristic parameter.

第３の発明による水底下探査装置は、水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を航行させつつ水底下にある物体を探査する水底下探査装置において、あらかじめ水底の凹凸を光学的又は音響的に計測する水底凹凸計測器と、その凹凸で散乱波が発生しにくい周波数を設定する周波数設定手段とを備え、その設定された周波数で音波を送波及び受波して上記探査を行うものである。   A submarine exploration device according to a third aspect of the present invention includes a wave transmitter that transmits sound waves in water and a wave receiver that receives scattered waves from an object on the underwater vehicle, and navigates the underwater vehicle. In a submarine exploration device for exploring an object under the water floor, the water bottom unevenness measuring instrument that measures the bottom unevenness optically or acoustically, and the frequency setting that sets the frequency at which the unevenness is less likely to generate scattered waves And the exploration is performed by transmitting and receiving a sound wave at the set frequency.

本発明は次の如き優れた効果を発揮する。   The present invention exhibits the following excellent effects.

（１）探査漏れを少なくすることができる。   (1) The leakage of exploration can be reduced.

以下、本発明の一実施形態を添付図面に基づいて詳述する。   Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

図１（ａ）に示されるように、本発明に係る水底下探査装置１は、水中に音波を送波する送波器２と、物体３からの散乱波を受波する受波器４と、これら送波器２及び受波器４を搭載する水中航行体５とを備え、その水中航行体５を航行させつつ水底下にある物体３を探査する水底下探査装置である。水中航行体５は、航行方向先頭が丸みを帯びている円筒または楕円筒形の外殻の後尾に取り付けた推進機構及び操舵機構（図示せず）並びにホバリング機構（図示せず）を有し、その外殻の内部に、送波器２と、受波アレイを構成する複数個の受波器４と、受波信号を増幅するアンプ６と、その受波信号を解析（解析内容は後述）する解析手段７と、バッテリ（図示せず）と、推進機構及び操舵機構を制御して水中航行体５が所定の航路に従って航行するようにする航行制御手段（図示せず）とを搭載する。   As shown in FIG. 1 (a), a submarine exploration device 1 according to the present invention includes a transmitter 2 that transmits sound waves into water, and a receiver 4 that receives scattered waves from an object 3. The underwater survey device includes an underwater navigation body 5 on which the transmitter 2 and the receiver 4 are mounted, and searches the object 3 under the water bottom while navigating the underwater navigation body 5. The underwater navigation body 5 has a propulsion mechanism and a steering mechanism (not shown) and a hovering mechanism (not shown) attached to the rear end of a cylindrical or elliptical cylindrical outer shell rounded in the navigation direction. Inside the outer shell, a transmitter 2, a plurality of receivers 4 constituting a receiving array, an amplifier 6 for amplifying a received signal, and the received signal are analyzed (the analysis content will be described later). Analysis means 7, a battery (not shown), and navigation control means (not shown) for controlling the propulsion mechanism and the steering mechanism so that the underwater vehicle 5 navigates along a predetermined route.

送波器２は、低周波、例えば３ｋＨｚの音波を送波するもので、航行方向側方から見た図１（ａ）、上から見た図１（ｂ）、航行方向後方から見た図１（ｃ）のいずれにおいても、指向性ビームの広がり幅が大きい（指向性が広い）ものである。   The transmitter 2 transmits a sound wave having a low frequency, for example, 3 kHz. FIG. 1 (a) viewed from the side of the navigation direction, FIG. 1 (b) viewed from the top, and a diagram viewed from the rear of the navigation direction. In all cases 1 (c), the spread width of the directional beam is large (the directivity is wide).

図１（ａ）に示されるように、航行方向側方から見たとき、送波の指向角閘は大きく、例えば４０ーである。送波の指向性の中心軸は鉛直方向であるが航行方向に傾けてもよい。また、図１（ｂ）に示されるように、上から見たとき、送波の指向性は水中航行体５の側方（後述する周回領域の内側）に向いている。さらに、図１（ｃ）に示されるように、航行方向後方から見たとき、指向性の中心軸は水底に対して傾いている。   As shown in FIG. 1A, when viewed from the side of the navigation direction, the directivity angle of transmission is large, for example, 40-. The central axis of directivity of transmission is the vertical direction, but it may be tilted in the navigation direction. Further, as shown in FIG. 1B, when viewed from above, the directivity of the transmission is directed to the side of the underwater vehicle 5 (inside the lap region described later). Furthermore, as shown in FIG. 1C, when viewed from the rear in the navigation direction, the central axis of directivity is inclined with respect to the water bottom.

図１（ｄ）に示されるように、水中航行体５からの音波があるレベルより高く到達するエリアを送波到達エリアｓとすると、水中航行体５が航行するに従い、送波到達エリアｓも移動する。物体３が送波到達エリアｓ内にあるとき、散乱波が発生する。このように、水中航行体５がかなり長い距離を航行する間、物体３からの散乱波を生じさせることができる。   As shown in FIG. 1D, when an area where the sound wave from the underwater vehicle 5 reaches higher than a certain level is defined as a transmission arrival area s, the transmission arrival area s is also increased as the underwater vehicle 5 navigates. Moving. When the object 3 is in the transmission arrival area s, a scattered wave is generated. Thus, while the underwater vehicle 5 travels a considerably long distance, a scattered wave from the object 3 can be generated.

受波器４は航行方向に複数個並べて配置される。これら複数個の受波器４による受波信号を公知のアルゴリズムに従って合成開口処理することにより、航行方向の幅が狭い範囲（検出指向性という）からの散乱波を検出することができる。   A plurality of receivers 4 are arranged side by side in the navigation direction. By performing synthetic aperture processing on the received signals from the plurality of receivers 4 according to a known algorithm, it is possible to detect scattered waves from a narrow range in the navigation direction (referred to as detection directivity).

また、その合成開口処理において各受波器４からの受波信号を合成するときのパラメータを変更することにより、検出指向性の中心の向きを変えることができる。そのパラメータを順次変更して、図１（ｅ）に示されるように、航行方向のベクトル成分が正の最大から負の最大まで順次異なる検出指向性ｒ１〜ｒ５を得ることができる。従って、この検出指向性の切り替えと図１（ｄ）の送波とを組み合わせると、水中航行体５の航行位置が少しずつ進んでいく小刻みな時間ごとに、送波と各検出指向性における受波を行うことで、受波水中航行体５がかなり長い距離を航行する間、同一物体３からの散乱波を異なる検出指向性角度から受波することができる。また、左右方向については、到達時間の違いにより散乱波の発生範囲を狭い左右方向範囲に限定できる。ただし、物体３にも特定の向きに音波を散乱させる散乱指向性があるので、物体３と水中航行体５との位置関係によって受波できないこともある。   In addition, the direction of the center of the detection directivity can be changed by changing the parameter when the received signal from each receiver 4 is combined in the synthetic aperture processing. By sequentially changing the parameters, as shown in FIG. 1E, detection directivities r1 to r5 in which the vector components in the navigation direction are sequentially different from the positive maximum to the negative maximum can be obtained. Therefore, when this switching of detection directivity and the transmission of FIG. 1 (d) are combined, the transmission and reception in each detection directivity are performed at every minute when the navigation position of the underwater vehicle 5 is gradually advanced. By performing the wave, the scattered wave from the same object 3 can be received from different detection directivity angles while the received underwater vehicle 5 travels a considerably long distance. Moreover, about the left-right direction, the generation range of a scattered wave can be limited to the narrow left-right direction range by the difference in arrival time. However, since the object 3 also has a scattering directivity that scatters sound waves in a specific direction, it may not be received depending on the positional relationship between the object 3 and the underwater vehicle 5.

図１の水底下探査装置１は、水中航行体５を所定の水域の周りで周回航行させつつその水域内の水底下にある物体３を探査するものである。これは図２（ａ）、図２（ｂ）に示されるように、物体３には散乱波の強さに分布があるが、適宜な大きさの水域の周囲を周回航行すれば、いずれかの位置で強い散乱波を捉えることができるという考えに基づく。その詳細は後述する。   The underwater survey device 1 in FIG. 1 searches for an object 3 under the water bottom in the water area while making the underwater navigation body 5 go around around a predetermined water area. As shown in FIG. 2 (a) and FIG. 2 (b), the object 3 has a distribution in the intensity of the scattered wave. Based on the idea that a strong scattered wave can be captured at the position of. Details thereof will be described later.

図２（ａ）の場合、水中航行体５はほぼ円を描いて周回する。図１（ｂ）のように航行方向右側に送波してその送波到達エリアｓからの散乱波を受波しつつ、図２（ａ）のように時計回り周回すれば、その周回航行で囲まれた円の水域Ｅａを探索することができる。   In the case of FIG. 2A, the underwater vehicle 5 circulates in a substantially circular shape. As shown in FIG. 1 (b), if the vehicle travels clockwise as shown in FIG. 2 (a) while receiving the scattered wave from the transmission arrival area s while transmitting to the right in the navigation direction, It is possible to search for the enclosed water area Ea.

また、図２（ｂ）の場合、水中航行体５はほぼ正方形を描いて周回するので、この正方形の水域Ｅｂを探索することができる。なお、水域の形状は、楕円でも長方形でも多角形でもよい。また、水中航行体５の右折角度は操舵可能な角度でよい。   Further, in the case of FIG. 2B, the underwater vehicle 5 circulates in a substantially square shape, so that this square water area Eb can be searched. The shape of the water area may be an ellipse, a rectangle, or a polygon. Further, the right turn angle of the underwater vehicle 5 may be a steerable angle.

さて、本発明の第１の特徴として、図１の水底下探査装置１は、あらかじめ水中の背景雑音や残響音を計測する背景雑音計測器と、この背景雑音や残響音が大きいときには上記水域を狭く設定し、上記背景雑音や残響音が小さいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行うものである。背景雑音計測器は、受波器４で代用可能である。また、水域設定手段は解析手段７に含まれる。   Now, as a first feature of the present invention, the underfloor exploration device 1 in FIG. 1 includes a background noise measuring device that measures background noise and reverberation in water in advance, and the water area when the background noise and reverberation are large. When the background noise and the reverberation sound are small, a water area setting means for setting the water area broadly is provided, and an exploration by the round navigation is performed around the set water area. The background noise measuring device can be replaced by the receiver 4. The water area setting means is included in the analysis means 7.

既に述べたように、物体の探査を行うには背景雑音よりも高いレベルの散乱波を受波しなければならない。また、周回の径を小さく（水域を狭く）すると、狭い領域しか探索できず、効率が良くないし、逆に、周回の径を大きく（水域を広く）すると、音波の減衰により散乱波の音圧が低下するので、周回の径をいたずらに大きくできない。そこで、本発明では、あらかじめ水中の背景雑音を計測しておいて周回の径（方形の場合は辺の長さ）を最適に設定するようにした。   As already described, in order to search for an object, it is necessary to receive a scattered wave at a level higher than the background noise. In addition, if the circle diameter is small (the water area is narrowed), only a narrow area can be searched, which is not efficient. Conversely, if the circle diameter is large (the water area is widened), the sound pressure of the scattered wave is reduced by the attenuation of the sound wave. As a result, the diameter of the circuit cannot be increased unnecessarily. Therefore, in the present invention, the background noise in the water is measured in advance, and the radius of the circuit (the length of the side in the case of a square) is set optimally.

すなわち、水底下探査装置１は、図１で説明した散乱波による探索を実施する前に、探査対象となっている広域において水中航行体５を航行させ、背景雑音計測を行う。このとき、送波器２からは音波を送波せずに、背景雑音計測器としての受波器４で背景雑音を計測する。受波信号はアンプで増幅して解析装置７に入力する。   In other words, the submarine exploration device 1 navigates the underwater vehicle 5 in the wide area that is the exploration target and performs background noise measurement before performing the search by the scattered wave described in FIG. At this time, the background noise is measured by the receiver 4 as a background noise measuring device without transmitting a sound wave from the transmitter 2. The received signal is amplified by an amplifier and input to the analysis device 7.

解析装置７は、受波した背景雑音の音圧を所定の基準値と比較する。背景雑音の音圧が基準値より大きければ、探査時の散乱波が背景雑音に妨害されやすいので、周回の径を小さく（水域を狭く）設定する。逆に、背景雑音の音圧が基準値より小さければ、探査時の散乱波が受波し易いので、周回の径を大きく（水域を広く）設定する。基準値は多段階に設けて設定が多段階にできるようにすると好ましい。背景雑音が場所により異なることもあるので、航行した航路の各ポイントごとに背景雑音の音圧や設定値をメモリに記憶しておく。   The analysis device 7 compares the sound pressure of the received background noise with a predetermined reference value. If the sound pressure of the background noise is larger than the reference value, the scattered wave at the time of exploration is likely to be disturbed by the background noise, so the diameter of the circle is set to be small (the water area is narrow). On the contrary, if the sound pressure of the background noise is smaller than the reference value, the scattered wave at the time of exploration is easy to be received, so the diameter of the circulation is set large (wide water area). Preferably, the reference value is provided in multiple stages so that the setting can be performed in multiple stages. Since the background noise may vary depending on the location, the sound pressure and setting value of the background noise is stored in the memory for each point on the route that has traveled.

その後、設定された水域の周りで周回航行による探査を行うと、周回の径を小さくしたときには、散乱波の音圧が相対的に大きくなり、探査漏れを少なくすることができる。周回の径を大きくしたときには、探査漏れが少ない状態を維持しつつ探査効率を高めることができる。   After that, when a search is performed around the set water area by round-trip navigation, the sound pressure of the scattered wave becomes relatively large and the search leakage can be reduced when the round-trip diameter is reduced. When the diameter of the circulation is increased, the search efficiency can be increased while maintaining a state in which the search leakage is small.

次に、本発明の第２の特徴として、図１の水底下探査装置１は、あらかじめ水中の音響特性パラメータを計測する音響特性パラメータ計測器と、この音響特性パラメータが散乱波を伝えにくい値のときには上記水域を狭く設定し、上記音響特性パラメータが散乱波を伝えやすいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行うものである。   Next, as a second feature of the present invention, the underwater exploration device 1 in FIG. 1 includes an acoustic characteristic parameter measuring device that measures an acoustic characteristic parameter in water in advance, and the acoustic characteristic parameter has a value that is difficult to transmit scattered waves. Sometimes the water area is set to be narrow, and when the acoustic characteristic parameter is easy to transmit scattered waves, the water area setting means for setting the water area to be wide is provided, and the exploration by the round navigation is performed around the set water area. .

ここで、音響特性パラメータ計測は、音響による計測と音響によらない計測があるので、これらを順に説明する。   Here, since the acoustic characteristic parameter measurement includes measurement by sound and measurement not by sound, these will be described in order.

図３に示されるように、水底下探査装置１に搭載される音響特性パラメータ計測器は、送波器２から試験波を送波して水底で散乱した散乱波を受波器４で受波する試験手段と、送波した信号と受波した信号の比較値として音響特性パラメータを計算する計算手段とを有する。ここでは、試験手段として信号発生器３１が設けられる。計算手段は解析手段７に含まれる。   As shown in FIG. 3, the acoustic characteristic parameter measuring instrument mounted on the submarine exploration apparatus 1 receives a scattered wave scattered by the water bottom by transmitting a test wave from the transmitter 2 by the receiver 4. And a test means for calculating an acoustic characteristic parameter as a comparison value between the transmitted signal and the received signal. Here, a signal generator 31 is provided as a test means. The calculation means is included in the analysis means 7.

水底下では、水底中での音のレベル減衰や音波の曲がりといった音響特性があり、水底下の物体を漏れなく探査するためには、これらの音響特性をあらかじめ知った上で、その音響特性を利用する必要がある。これらは、散乱波の音圧に関連してくる。そこで、本発明では、あらかじめ水底の音響特性パラメータ（音速、媒質密度、音の減衰係数など）を計測しておいて周回の径（方形の場合は辺の長さ）を最適に設定するようにした。   Under the bottom of the water, there are acoustic characteristics such as sound level attenuation and bending of the sound wave in the bottom of the water. Need to use. These are related to the sound pressure of the scattered wave. Therefore, in the present invention, acoustic characteristic parameters (such as sound speed, medium density, sound attenuation coefficient, etc.) of the bottom of the water are measured in advance, and the diameter of the circuit (the length of the side in the case of a square) is set optimally. did.

すなわち、水底下探査装置１は、図１で説明した散乱波による探索を実施する前に、探査対象となっている広域において水中航行体５を航行させ、音響特性パラメータ計測を行う。水中航行体５は、航行経路のある地点ごとに航行を停止して、水底からある高さにホバリングする。このとき、送波器２からは信号発生器３１からの試験波をアンプ３２により送波器２に送り、送波器２からその音波を水底に向けて送波させ、水底からの散乱波を受波器４で受波する。受波信号はアンプで増幅して解析装置７に入力する。水中航行体５は、同じ地点においてホバリングで上昇（又は下降）し、繰り返し試験波の送受を行う。   That is, the submarine exploration device 1 navigates the underwater vehicle 5 in the wide area to be explored and performs acoustic characteristic parameter measurement before performing the search using the scattered wave described with reference to FIG. The underwater vehicle 5 stops navigation at each point on the navigation route and hoveres to a certain height from the bottom of the water. At this time, the test wave from the signal generator 31 is sent from the transmitter 2 to the transmitter 2 by the amplifier 32, and the sound wave is sent from the transmitter 2 toward the bottom of the water, and the scattered wave from the bottom of the water is sent. The wave is received by the receiver 4. The received signal is amplified by an amplifier and input to the analysis device 7. The underwater vehicle 5 ascends (or descends) by hovering at the same point, and repeatedly transmits and receives test waves.

解析装置７は、数箇所の高さで計測した散乱波レベルを基に、音速、媒質密度、音の減衰係数などの音響特性パラメータを推定する。例えば、非特許文献１に記載の逆問題解析方法を用いて、水底における音響インピーダンス（音速と媒質密度の積）を推定する。この音響インピーダンスと音の減衰係数との相関関係などを用いて音の減衰係数を推定する。   The analysis device 7 estimates acoustic characteristic parameters such as sound speed, medium density, and sound attenuation coefficient based on the scattered wave levels measured at several heights. For example, using the inverse problem analysis method described in Non-Patent Document 1, the acoustic impedance (product of sound speed and medium density) at the bottom of the water is estimated. The sound attenuation coefficient is estimated using the correlation between the acoustic impedance and the sound attenuation coefficient.

解析装置７は、音響特性パラメータをもとに、音線法やノーマルモード法やＰＥ法などの音波伝搬の予測計算を行い、探査が可能な程度の散乱波が受波できるように、周回の径（水域の広さ）を設定する。音響特性パラメータが場所により異なることもあるので、航行した航路の各ポイントごとに背景雑音の音圧や設定値をメモリに記憶しておく。   The analysis device 7 performs sound wave propagation prediction calculation such as the sound ray method, normal mode method, and PE method based on the acoustic characteristic parameters, so that the scattered waves can be received so as to be able to be probed. Set the diameter (width of the water area). Since the acoustic characteristic parameter may vary depending on the location, the sound pressure and set value of the background noise is stored in the memory for each point on the route that has traveled.

その後、設定された水域の周りで周回航行による探査を行うと、周回の径を小さくしたときには、散乱波の音圧が相対的に大きくなり、探査漏れを少なくすることができる。周回の径を大きくしたときには、探査漏れが少ない状態を維持しつつ探査効率を高めることができる。   After that, when a search is performed around the set water area by round-trip navigation, the sound pressure of the scattered wave becomes relatively large and the search leakage can be reduced when the round-trip diameter is reduced. When the diameter of the circulation is increased, the search efficiency can be increased while maintaining a state in which the search leakage is small.

図４に示されるように、水底下探査装置１に搭載される音響特性パラメータ計測器は、水温、不純物濃度などの水の特性値を計測する水特性値計測器と、この水の特性値から音速を推定する推定手段とを有する。ここでは、水特性値計測器として水温計４１と、塩分濃度計４２が設けられる。推定手段は解析手段７に含まれる。   As shown in FIG. 4, the acoustic characteristic parameter measuring instrument mounted on the submarine exploration device 1 includes a water characteristic value measuring instrument that measures water characteristic values such as water temperature and impurity concentration, and the characteristic values of the water. Estimation means for estimating the speed of sound. Here, a water temperature meter 41 and a salinity concentration meter 42 are provided as water characteristic value measuring devices. The estimation means is included in the analysis means 7.

既に述べたように、水中では、水温や不純物濃度（特に海域では塩分濃度）によって音速が異なる。音速が異なると距離計測に影響すると共に、水温や不純物濃度が場所によって異なる分布をしていると、音速の分布が不均一になり、音波の曲がりが生じる。そこで、本発明では、水の特性値を計測してその特性値から音速を推定する。事前に水中航行体５を航行させて水の特性値を計測を行うことにより、音速等の音響特性パラメータの航行方向分布が得られる。   As already mentioned, in water, the speed of sound varies depending on the water temperature and impurity concentration (especially salt concentration in the sea area). If the sound speed is different, distance measurement is affected, and if the water temperature and the impurity concentration are distributed differently depending on the location, the sound speed distribution becomes non-uniform and the sound wave is bent. Therefore, in the present invention, the characteristic value of water is measured and the sound speed is estimated from the characteristic value. By navigating the underwater vehicle 5 in advance and measuring the characteristic value of water, the navigation direction distribution of acoustic characteristic parameters such as sound speed can be obtained.

具体的には、水中航行体５は、航行経路のある地点ごとに航行を停止して、水底からある高さにホバリングする。その高さで水温と不純物濃度を計測した後、同じ地点においてホバリングで上昇（又は下降）し、繰り返し水温と不純物濃度を計測する。推定手段としての解析手段７には、あらかじめ推定式が設けられており、この推定式に各計測値を適用して音速等の音響特性パラメータを推定する。高さを変えて行うことにより、高さ方向の分布が得られる。   Specifically, the underwater vehicle 5 stops navigation at each point on the navigation route and hover to a certain height from the bottom of the water. After measuring the water temperature and the impurity concentration at the height, the water temperature is raised (or lowered) at the same point by hovering, and the water temperature and the impurity concentration are repeatedly measured. The analysis means 7 as the estimation means is provided with an estimation formula in advance, and the acoustic characteristic parameters such as the sound speed are estimated by applying each measurement value to the estimation formula. By changing the height, a distribution in the height direction can be obtained.

解析装置７は、音響特性パラメータをもとに、音線法やノーマルモード法やＰＥ法などの音波伝搬の予測計算を行い、探査が可能な程度の散乱波が受波できるように、周回の径（水域の広さ）を設定する。（水底下物体を探索する場合に水底面下に音波を透過させる必要がある。水中及び水底の音速の関係から、これよりは浅い角度では音波が透過しない臨界角が存在する。水中で音速分布がある場合には水中で音波に曲がりが生じる。そのため、水底面に対し角度が大きくなるような曲がりを持つ場合には周回の径を広くでき、逆に水底面に対し角度が小さくなるような曲がりを持つ場合には周回の径を狭くする必要がある。）
その後、設定された水域の周りで周回航行による探査を行うと、周回の径を小さくしたときには、散乱波の音圧が相対的に大きくなり、探査漏れを少なくすることができる。周回の径を大きくしたときには、探査漏れが少ない状態を維持しつつ探査効率を高めることができる。 The analysis device 7 performs sound wave propagation prediction calculation such as a sound ray method, a normal mode method, and a PE method on the basis of the acoustic characteristic parameters, so that a scattered wave that can be searched can be received. Set the diameter (width of the water area). (When searching for an object under the bottom of the water, it is necessary to transmit sound waves below the bottom of the water. From the relationship between the sound speed of water and the bottom of the water, there is a critical angle at which the sound wave does not transmit at shallower angles. When there is a bend, the sound wave bends in water, so if the bend has a large angle with respect to the bottom surface, the diameter of the circuit can be increased, and conversely the angle becomes smaller with respect to the bottom surface. (If it has a bend, it is necessary to narrow the circumference diameter.)
After that, when a search is performed around the set water area by round-trip navigation, the sound pressure of the scattered wave becomes relatively large and the search leakage can be reduced when the round-trip diameter is reduced. When the diameter of the circulation is increased, the search efficiency can be increased while maintaining a state where there are few search leaks.

次に、本発明の第３の特徴として、図１の水底下探査装置１は、あらかじめ水底の凹凸を計測する水底凹凸計測器と、その凹凸で散乱波が発生しにくい周波数を設定する周波数設定手段とを備え、その設定された周波数で音波を送波及び受波して上記探査を行う。図５に詳しく示すように、水底凹凸計測器５１は、カメラ５２、サイドスキャンソーナー５３など１種類以上の機器で構成され、それぞれの機器による計測結果を複合できる。カメラ５２は、複数箇所から同一対象を撮像することで立体視可能なものである。サイドスキャンソーナー５３は特定方向の対象との距離を計測可能なソーナーを航行方向側方に掃引するものである。周波数設定手段は解析手段７に含まれる。   Next, as a third feature of the present invention, the underfloor exploration apparatus 1 in FIG. 1 sets a water bottom unevenness measuring instrument that measures the unevenness of the waterbed in advance and a frequency setting that sets a frequency at which scattered waves are not easily generated by the unevenness. Means for transmitting and receiving the sound wave at the set frequency and performing the search. As shown in detail in FIG. 5, the water bottom unevenness measuring instrument 51 is composed of one or more types of devices such as a camera 52 and a side scan sonar 53, and the measurement results obtained by the respective devices can be combined. The camera 52 can be stereoscopically viewed by imaging the same object from a plurality of locations. The side scan sonar 53 sweeps a sonar capable of measuring a distance from a target in a specific direction in the navigation direction side. The frequency setting means is included in the analysis means 7.

既に述べたように、水底に水流などによりできた凹凸があると、凹凸からの散乱波が探査の妨害になる。また、凹凸の間隔や高さにより、散乱波のレベルが小さくなる周波数がある。そこで、本発明では、水底の凹凸を事前に計測しておき、散乱波のレベルが小さくなる周波数を設定する。   As already mentioned, if the bottom of the water has unevenness due to water flow, scattered waves from the unevenness hinder the exploration. Further, there is a frequency at which the level of the scattered wave is reduced depending on the interval and height of the unevenness. Therefore, in the present invention, the unevenness of the bottom of the water is measured in advance, and the frequency at which the level of the scattered wave is reduced is set.

具体的には、水底下探査装置１（図５の水底凹凸計測器）は、水中航行体５を事前に航行させながら、カメラ５２で水底を撮影し、その映像から凹凸を認識し、サイドスキャンソーナー５３の掃引による水底との距離を複合して凹凸を計測する。このようにして事前に計測した凹凸をメモリに記憶する。周波数設定手段としての解析手段７は、この凹凸に基づいて、例えば非特許文献２に記載の散乱レベル予測計算を行い、物体３の探査に適した周波数として、凹凸からの散乱波が発生しにくい周波数を設定する。   Specifically, the underfloor exploration device 1 (water bottom unevenness measuring instrument in FIG. 5) takes a photograph of the water bottom with a camera 52 while navigating the underwater vehicle 5 in advance, recognizes unevenness from the image, and performs side scan. The unevenness is measured by combining the distance from the water bottom by sweeping of the sonar 53. Thus, the unevenness measured in advance is stored in the memory. Based on the unevenness, the analyzing means 7 as the frequency setting means performs the scattering level prediction calculation described in Non-Patent Document 2, for example, and the scattered wave from the unevenness is hardly generated as a frequency suitable for the search for the object 3. Set the frequency.

続いて、水底下探査装置１は、図６に示されるように、水中航行体５を航行させながら、残響レベルを計測し、メモリに記憶する。残響レベルは、信号発生器３１により残響計測用のパルス又はステップ状の送波信号を発生させ、その後の時間経過において受波器４で受波される受波信号のレベルで計測される。これにより、あるパルス又はステップ状の送波信号を送波したときに残響のレベルが実測される。周波数を変えたパルス又はステップ状の送波信号でこの残響レベル計測を行い、水底の凹凸からの残響が生じにくい周波数を選定する。   Subsequently, as shown in FIG. 6, the underfloor exploration device 1 measures the reverberation level while navigating the underwater vehicle 5 and stores it in the memory. The reverberation level is measured at the level of the received signal that is received by the receiver 4 over time after the signal generator 31 generates a reverberation measuring pulse or stepped transmission signal. Thereby, the reverberation level is measured when a certain pulse or step-like transmission signal is transmitted. This reverberation level is measured with a pulse or step-like transmission signal with a different frequency, and a frequency at which reverberation from the unevenness of the bottom of the water does not easily occur is selected.

次に、これまで述べた種々の機能を全て備えた場合の、水底下探査装置１の動作シーケンスを説明する。   Next, the operation sequence of the underwater survey device 1 when all the various functions described so far are provided will be described.

図７に示されるように、水底下探査装置１は、ステップＳ１；図３で説明した音響による音響特性パラメータ計測モード、ステップＳ２；図４で説明した水の特性による水中音速分布計測モード、ステップＳ３；図５で説明した水底の凹凸計測モード、ステップＳ４；図１で説明した背景雑音計測モード、ステップＳ５；図６で説明した残響レベル計測モードを実行した後、ステップＳ６で初期値を設定し、ステップＳ７で物体散乱波レベル推定計算を行う。初期値は、ステップＳ１，Ｓ２で計測したパラメータ値とステップＳ３により決定された送波する音波の周波数及び物体への音波の入射角、送波する音波の大きさを表す送波レベルなどを入力する。物体散乱波レベル推定計算は、これから探査しようとする対象の物体がどの程度の散乱波を生じるかをあらかじめ推定する計算であり、物体の性状や形状が既知であれば公知の方法で推定可能である。   As shown in FIG. 7, the underfloor exploration device 1 includes: step S1; acoustic characteristic parameter measurement mode by sound described in FIG. 3; step S2; underwater sound velocity distribution measurement mode by water characteristic described in FIG. S3: Water bottom unevenness measurement mode described in FIG. 5, Step S4; Background noise measurement mode described in FIG. 1, Step S5; Reverberation level measurement mode described in FIG. 6 is executed, and initial values are set in Step S6. In step S7, the object scattered wave level estimation calculation is performed. As the initial value, the parameter value measured in steps S1 and S2, the frequency of the sound wave to be transmitted determined in step S3, the incident angle of the sound wave to the object, the transmission level indicating the magnitude of the sound wave to be transmitted, and the like are input. To do. The object scattered wave level estimation calculation is a calculation to estimate in advance how much scattered waves will be generated by the target object to be explored, and if the object's properties and shape are known, it can be estimated by a known method. is there.

ステップＳ８において、周回航行する水域の最大の半径又は辺の長さを決定する。ここで、この最大の半径又は辺の長さは、ステップＳ７で推定された物体散乱波レベルがステップＳ４で計測された背景雑音レベル及びステップＳ５で計測された残響レベルより大きく（あるいは十分に大きく）なる範囲の最大の長さで決定する。   In step S8, the maximum radius or side length of the water area that goes round is determined. Here, the maximum radius or side length is larger (or sufficiently larger) than the background noise level measured in step S4 and the reverberation level measured in step S5 in the object scattered wave level estimated in step S7. ) Is determined by the maximum length of the range.

次に、水中航行体５を水域Ｅａ，Ｅｂの周りで周回航行させつつ物体３を探査する方法の原理及び利点を補足説明しておく。   Next, the principle and advantage of the method for exploring the object 3 while navigating the underwater vehicle 5 around the water areas Ea and Eb will be supplementarily described.

図８（ａ）〜図８（ｄ）に示されるように、物体３として端面を約１時の角度に向けて水平に置かれた円筒体があるとき、その物体３に臨む様々の方向から広い指向性で音波を送波したとき、物体３を中心とした所定径の円内における散乱波の音圧分布の形状は、送波方向に依存して変形する。すなわち、図８（ａ）のように約８時の角度から物体３に向けて音波を送波したとき、音圧の高い部分は約１２〜約３時の角度の間に二股に分かれて生じる。図８（ｂ）のように約９時の角度から物体３に向けて音波を送波したとき、音圧の高い部分は約１１時の角度と約３時の角度に生じる。図８（ｃ）のように約１０時の角度から物体３に向けて音波を送波したとき、音圧の高い部分は約１０時の角度と約４時の角度に生じる。図８（ｄ）のように約１０時半の角度から物体３に向けて音波を送波したとき、音圧の高い部分は約１０時の角度と約４時半の角度に生じる。これらから分かるように、送波の角度に応じて音圧分布が大きく異なる。   As shown in FIG. 8A to FIG. 8D, when there is a cylindrical body that is horizontally placed with the end face facing an angle of about 1 o'clock as the object 3, the object 3 can be viewed from various directions facing the object 3. When a sound wave is transmitted with a wide directivity, the shape of the sound pressure distribution of the scattered wave within a circle having a predetermined diameter centered on the object 3 is deformed depending on the transmission direction. That is, as shown in FIG. 8A, when a sound wave is transmitted toward the object 3 from the angle of about 8 o'clock, the high sound pressure portion is divided into two forks between the angle of about 12 to about 3 o'clock. . When a sound wave is transmitted toward the object 3 from an angle of about 9 o'clock as shown in FIG. 8B, a high sound pressure portion occurs at an angle of about 11 o'clock and an angle of about 3 o'clock. When a sound wave is transmitted toward the object 3 from an angle of about 10 o'clock as shown in FIG. 8C, a high sound pressure portion occurs at an angle of about 10 o'clock and an angle of about 4 o'clock. When a sound wave is transmitted toward the object 3 from an angle of about 10:30 as shown in FIG. 8D, a high sound pressure portion occurs at an angle of about 10 o'clock and an angle of about 4:30. As can be seen from these, the sound pressure distribution varies greatly depending on the angle of transmission.

図９（ａ）〜図９（ｄ）に示されるように、図８と同じ条件にて、水中航行体５が直線状に航行しながら斜め前方、側方、斜め後方を含む広い指向性で音波を送波すると、水中航行体５の位置により、送波された音波が物体３に向かう角度が異なるため、音圧分布が異なる。水中航行体５が受波する音波のうち物体３による散乱波の成分は、図９（ｃ）のとき音圧が高い。よって、図９のケースでは図９（ｃ）の前後の範囲において物体３からの散乱波を検出できることが期待される。ただし、図９（ｄ）のように水中航行体５の位置がわずかに異なるだけで散乱波を検出できない場合も有り得る。   As shown in FIGS. 9A to 9D, under the same conditions as in FIG. 8, the underwater vehicle 5 travels in a straight line with wide directivity including diagonally forward, sideward, and diagonally rearward. When the sound wave is transmitted, the angle of the transmitted sound wave toward the object 3 differs depending on the position of the underwater vehicle 5, so that the sound pressure distribution is different. Among the sound waves received by the underwater vehicle 5, the component of the scattered wave by the object 3 has a high sound pressure as shown in FIG. Therefore, in the case of FIG. 9, it is expected that the scattered wave from the object 3 can be detected in the range before and after FIG. 9C. However, as shown in FIG. 9D, there may be a case where the scattered wave cannot be detected only by slightly different positions of the underwater vehicle 5.

物体３の向きが異なると図８、図９とは異なる音圧分布となるため、図９のように直線状に航行したとき、音圧の高い角度に入らないまま通り過ぎてしまうことが考えられる。そこで、図２（ａ）、図２（ｂ）のように、水中航行体５を水域Ｅａ，Ｅｂの周りで周回航行させると、音圧の高い角度に入る機会が提供される。   When the direction of the object 3 is different, the sound pressure distribution is different from that in FIGS. 8 and 9. Therefore, when navigating in a straight line as shown in FIG. 9, it may pass without entering the high sound pressure angle. . Therefore, as shown in FIGS. 2 (a) and 2 (b), when the underwater vehicle 5 travels around the water areas Ea and Eb, an opportunity to enter an angle with a high sound pressure is provided.

本発明では、このような周回航行に際して、水中及び水底音速分布と水底の音響パラメータを計測し、それらを入力とした物体からの散乱波レベルの予測計算を行い、物体からの散乱波レベルが背景雑音及び残響音よりも大きくなるように、周回の径（水域の広さ）を最適に設定するようにしたので、探査漏れを少なくすることができる。   In the present invention, during such round-trip navigation, underwater and bottom sound velocity distributions and bottom acoustic parameters are measured, and the scattered wave level from the object is calculated using these as input, and the scattered wave level from the object is the background. Since the diameter of the circulation (the width of the water area) is optimally set so as to be larger than the noise and the reverberant sound, it is possible to reduce the leakage of the search.

また、本発明では、直線航行、周回航行に関わらず、あらかじめ水底の凹凸を計測し、その凹凸で散乱波が発生しにくい周波数を設定して探査を行うようにしたので、探査漏れを少なくすることができる。   In addition, in the present invention, regardless of whether the navigation is a straight line or a round trip, the unevenness of the bottom of the water is measured in advance, and the search is performed by setting the frequency at which the uneven wave is less likely to generate a scattered wave. be able to.

本発明の一実施形態を示す水底下探査装置の、（ａ）側面図、（ｂ）平面図、（ｃ）後面図、（ｄ）送波イメージ図、（ｅ）受波イメージ図である。BRIEF DESCRIPTION OF THE DRAWINGS It is (a) side view, (b) top view, (c) rear view, (d) transmitted image figure, (e) received image figure of the submarine exploration apparatus which shows one Embodiment of this invention. 本発明において水域の周囲を周回航行することを説明する平面図である。It is a top view explaining navigating around the water area in this invention. 本発明において音響により音響特性パラメータを計測することを説明する側面図である。It is a side view explaining measuring an acoustic characteristic parameter by sound in the present invention. 本発明において水温、濃度により音響特性パラメータを計測することを説明する側面図である。It is a side view explaining measuring an acoustic characteristic parameter by water temperature and concentration in the present invention. 本発明において水底凹凸を計測することを説明する側面図である。It is a side view explaining measuring water bottom unevenness in the present invention. 本発明において残響レベルを計測することを説明する側面図である。It is a side view explaining measuring a reverberation level in the present invention. 本発明に係る水底下探査装置の動作シーケンス図である。It is an operation | movement sequence diagram of the submarine investigation apparatus which concerns on this invention. （ａ）〜（ｄ）は、物体に向けて音波を送波したときの散乱波の音圧分布を示す平面音圧分布図である。(A)-(d) is a plane sound pressure distribution figure which shows the sound pressure distribution of a scattered wave when a sound wave is transmitted toward an object. （ａ）〜（ｄ）は、水中航行体から音波を送波したときに物体から生じる散乱波の音圧分布を示す平面音圧分布図である。(A)-(d) is a plane sound pressure distribution figure which shows the sound pressure distribution of the scattered wave which arises from an object, when a sound wave is transmitted from an underwater vehicle.

符号の説明Explanation of symbols

１ 水底下探査装置
２ 送波器
３ 物体
４ 受波器
５ 水中航行体
７ 解析装置 DESCRIPTION OF SYMBOLS 1 Underwater exploration device 2 Transmitter 3 Object 4 Receiver 5 Underwater vehicle 7 Analysis device

Claims (9)

水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査方法において、あらかじめ水中の背景雑音や残響音を計測し、この背景雑音や残響音が大きいときには上記水域を狭く設定し、上記背景雑音や残響音が小さいときには上記水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うことを特徴とする水底下探査方法。   An underwater vehicle is equipped with a transmitter for transmitting sound waves into the water and a receiver for receiving scattered waves from the object, and the underwater vehicle is circulated around a predetermined water region while moving around the water region. In the submarine exploration method for exploring objects under the water floor in the water, the background noise and reverberation sound in the water are measured in advance, and when the background noise and reverberation sound are large, the above water area is set narrow, and the background noise and reverberation sound are A submarine exploration method characterized in that when the water is small, the water area is set broadly and exploration is performed around the set water area by the round-trip navigation. 水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査方法において、あらかじめ水底の音響特性パラメータ（音速、密度、減衰係数）を計測し、この音響特性パラメータを用いた音波伝搬解析を行い、水底が音波を伝えにくいときには上記水域を狭く設定し、水底が音波を伝えやすいときには上記水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うことを特徴とする水底下探査方法。   An underwater vehicle is equipped with a transmitter for transmitting sound waves into the water and a receiver for receiving scattered waves from the object, and the underwater vehicle is circulated around a predetermined water region while moving around the water region. In the submarine exploration method for exploring objects under the bottom of the water, acoustic characteristics parameters (sound speed, density, attenuation coefficient) of the bottom are measured in advance, and sound propagation analysis is performed using these acoustic characteristics parameters. A submarine exploration method characterized in that the water area is set narrow when it is difficult to convey water, and the water area is set wide when the water bottom is easy to convey sound waves, and the exploration is carried out around the set water area by the circular navigation. 上記音響特性パラメータは、上記送波器から試験波を送波して水底で反射した音波を上記受波器で受波し、受波した信号を用い逆問題解析計算により求めることを特徴とする請求項２記載の水底下探査方法。   The acoustic characteristic parameter is obtained by transmitting a test wave from the transmitter, receiving a sound wave reflected from the bottom of the water with the receiver, and calculating the acoustic characteristics by inverse problem analysis calculation using the received signal. The underwater survey method according to claim 2. 水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を航行させつつ水底下にある物体を探査する水底下探査方法において、あらかじめ水底の凹凸を計測し、その凹凸を入力値にした音波伝搬解析を行い、水底下に音波を伝えにくいときには上記水域を狭く設定し、水底下に音波が伝えやすいときには水域を広く設定し、この設定された水域の周りで上記周回航行による探査を行うことを特徴とする水底下探査方法。   A water probe that transmits sound waves into the water and a receiver that receives scattered waves from the object are mounted on the underwater vehicle, and the water that explores the object under the bottom of the water while navigating the underwater vehicle In the bottom-bottom exploration method, the unevenness of the bottom of the water is measured in advance, and the sound wave propagation analysis is performed using the unevenness as an input value. When it is difficult to transmit the sound wave below the bottom of the water, the above water area is set narrow, and when the sound wave is easily transmitted below the bottom of the water A submarine exploration method characterized in that exploration by the above-mentioned round navigation is performed around the set water area. 凹凸に応じて音波が伝わりやすい周波数を用いることを特徴とする請求項４記載の水底下探査方法。   The submarine survey method according to claim 4, wherein a frequency at which a sound wave is easily transmitted according to the unevenness is used. 水中に音波を送波する送波器と、物体からの散乱波を受波する受波器と、これら送波器及び受波器を搭載する水中航行体とを備え、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査装置において、あらかじめ水中の背景雑音や残響音を計測する背景雑音計測器と、この背景雑音や残響音が大きいときには上記水域を狭く設定し、上記背景雑音や残響音が小さいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行うことを特徴とする水底下探査装置。   A transmitter for transmitting sound waves into water, a receiver for receiving scattered waves from an object, and an underwater vehicle equipped with these transmitters and receivers. In a submarine exploration device that explores an object below the bottom of the water while navigating around the body of water, a background noise measuring device that measures background noise and reverberation in water, and this background noise and reverberation A water area setting means for setting the water area narrow when the background noise and reverberation sound are small, and performing the exploration by the round navigation around the set water area. Underwater exploration device. 水中に音波を送波する送波器と、物体からの散乱波を受波する受波器と、これら送波器及び受波器を搭載する水中航行体とを備え、その水中航行体を所定の水域の周りで周回航行させつつ該水域内の水底下にある物体を探査する水底下探査装置において、あらかじめ水底の音響特性パラメータ（音速、密度、減衰係数）を計測する音響特性パラメータ計測器と、この音響特性パラメータを用いた音波伝搬解析を行う音波伝搬解析手段と、水底が音波を伝えにくいときには上記水域を狭く設定し、水底が音波を伝えやすいときには上記水域を広く設定する水域設定手段とを備え、この設定された水域の周りで上記周回航行による探査を行うことを特徴とする水底下探査装置。   A transmitter for transmitting sound waves into water, a receiver for receiving scattered waves from an object, and an underwater vehicle equipped with these transmitters and receivers. An acoustic characteristic parameter measuring instrument that measures acoustic characteristics parameters (sound speed, density, attenuation coefficient) of the bottom in advance in a submarine exploration device that explores an object under the bottom of the water while navigating around A sound wave propagation analyzing means for performing sound wave propagation analysis using this acoustic characteristic parameter, and a water area setting means for setting the water area narrow when the water bottom is difficult to transmit sound waves, and a water area setting means for setting the water area wide when the water bottom is easy to transmit sound waves. And a submarine exploration device that performs exploration by the above-mentioned round navigation around the set water area. 上記音響特性パラメータ計測器は、上記送波器から試験波を送波して水底で反射した音波を上記受波器で受波する試験手段と、受波した信号を用い逆問題解析計算により音響特性パラメータを推定する音響特性パラメータ推定手段とを有することを特徴とする請求項７記載の水底下探査装置。   The acoustic characteristic parameter measuring instrument includes a test means for transmitting a test wave from the transmitter and receiving the sound wave reflected from the bottom of the water by the receiver, and an acoustic analysis by inverse problem analysis calculation using the received signal. The underwater exploration device according to claim 7, further comprising acoustic characteristic parameter estimation means for estimating the characteristic parameter. 水中に音波を送波する送波器と、物体からの散乱波を受波する受波器とを水中航行体に搭載し、その水中航行体を航行させつつ水底下にある物体を探査する水底下探査装置において、あらかじめ水底の凹凸を光学的又は音響的に計測する水底凹凸計測器と、その凹凸で散乱波が発生しにくい周波数を設定する周波数設定手段とを備え、その設定された周波数で音波を送波及び受波して上記探査を行うことを特徴とする水底下探査装置。   Water that explores an object under the seafloor while navigating the underwater vehicle with a transmitter that transmits sound waves into the water and a receiver that receives scattered waves from the object. The bottom survey device is equipped with a water bottom unevenness measuring instrument that optically or acoustically measures the bottom unevenness and a frequency setting means for setting a frequency at which scattered waves are not easily generated by the unevenness, and at the set frequency. A submarine exploration device that conducts the exploration by transmitting and receiving sound waves.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010190682A (en) * 2009-02-17 2010-09-02 Ihi Corp Method and apparatus for exploring and classifying object in the bottom of water
JP2012122758A (en) * 2010-12-06 2012-06-28 Ihi Corp Method for exploring and classifying object in the bottom of water
CN108802739A (en) * 2018-05-31 2018-11-13 深圳臻迪信息技术有限公司 A kind of underwater obstacle detection method and detection device
JP2020052053A (en) * 2013-03-15 2020-04-02 ハダル， インコーポレイテッド Systems and methods for navigating autonomous unmanned underwater vehicles
CN113091887A (en) * 2021-04-22 2021-07-09 中国人民解放军92578部队 Device and method for testing flow-induced noise of underwater vehicle based on gravity type water tunnel

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05223923A (en) * 1992-02-18 1993-09-03 Oki Electric Ind Co Ltd Method and apparatus for detecting buried structure
JPH09178851A (en) * 1995-12-26 1997-07-11 Ishikawajima Harima Heavy Ind Co Ltd Forward search device for shield machine
JPH09274081A (en) * 1996-04-03 1997-10-21 Tech Res & Dev Inst Of Japan Def Agency Sound-velocity measuring method in submarine sedimentary layer
JP2000206228A (en) * 1999-01-12 2000-07-28 Nec Corp Underwater sound transmitter and underwater acoustic transducer
JP2000227475A (en) * 1999-02-08 2000-08-15 Nec Corp Echo sounder searching factor optimizing device
JP2004101251A (en) * 2002-09-06 2004-04-02 Nec Corp System for using search of underwater object, and program for search
JP2004184268A (en) * 2002-12-04 2004-07-02 Ishikawajima Harima Heavy Ind Co Ltd Underwater resources exploring method and system thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05223923A (en) * 1992-02-18 1993-09-03 Oki Electric Ind Co Ltd Method and apparatus for detecting buried structure
JPH09178851A (en) * 1995-12-26 1997-07-11 Ishikawajima Harima Heavy Ind Co Ltd Forward search device for shield machine
JPH09274081A (en) * 1996-04-03 1997-10-21 Tech Res & Dev Inst Of Japan Def Agency Sound-velocity measuring method in submarine sedimentary layer
JP2000206228A (en) * 1999-01-12 2000-07-28 Nec Corp Underwater sound transmitter and underwater acoustic transducer
JP2000227475A (en) * 1999-02-08 2000-08-15 Nec Corp Echo sounder searching factor optimizing device
JP2004101251A (en) * 2002-09-06 2004-04-02 Nec Corp System for using search of underwater object, and program for search
JP2004184268A (en) * 2002-12-04 2004-07-02 Ishikawajima Harima Heavy Ind Co Ltd Underwater resources exploring method and system thereof

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010190682A (en) * 2009-02-17 2010-09-02 Ihi Corp Method and apparatus for exploring and classifying object in the bottom of water
JP2012122758A (en) * 2010-12-06 2012-06-28 Ihi Corp Method for exploring and classifying object in the bottom of water
JP2020052053A (en) * 2013-03-15 2020-04-02 ハダル， インコーポレイテッド Systems and methods for navigating autonomous unmanned underwater vehicles
JP7183142B2 (en) 2013-03-15 2022-12-05 ハダル， インコーポレイテッド Systems and methods for navigating autonomous underwater vehicles
CN108802739A (en) * 2018-05-31 2018-11-13 深圳臻迪信息技术有限公司 A kind of underwater obstacle detection method and detection device
CN113091887A (en) * 2021-04-22 2021-07-09 中国人民解放军92578部队 Device and method for testing flow-induced noise of underwater vehicle based on gravity type water tunnel

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