JPS629284A - Laser sounding device - Google Patents

Laser sounding device

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Publication number
JPS629284A
JPS629284A JP14849585A JP14849585A JPS629284A JP S629284 A JPS629284 A JP S629284A JP 14849585 A JP14849585 A JP 14849585A JP 14849585 A JP14849585 A JP 14849585A JP S629284 A JPS629284 A JP S629284A
Authority
JP
Japan
Prior art keywords
pulse
laser
photomultiplier
gate
gate pulse
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP14849585A
Other languages
Japanese (ja)
Other versions
JPH0564750B2 (en
Inventor
Takaharu Kameyama
亀山 隆治
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP14849585A priority Critical patent/JPS629284A/en
Publication of JPS629284A publication Critical patent/JPS629284A/en
Publication of JPH0564750B2 publication Critical patent/JPH0564750B2/ja
Granted legal-status Critical Current

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Abstract

PURPOSE:To increase a sounding accuracy by providing the photo shutter device to check the incident laser beam on a photomultiplier by receiving a gate pulse signal, a gate pulse generator and timing setter. CONSTITUTION:The reflecting echo signal from the sea level and sea bottom is made incident on a photomultiplier 11 via an interference filter 18, reflecting mirror 17, polarizor 19, photo shutter element 21 and verifier 20. A photo detecting element 26 then detects one part of the pulse output of a pulse laser device 1 and the output pulse thereof is led to a differential time measuring circuit 23. On the other hand the reflecting echo signal from the sea level is led to the circuit 23 as well and the differential time thereof is set (24). The output pulse of the following pulse 26 is then detected, a trigger pulse output is transmitted to high pressure pulsor 15 and 22 from the circuit 24 and the gate pulse for actuating the photomultiplier 11 and element 21 is outputted. The photomultiplier 11 remains in the gate-off state until the echo from the sea bottom arrives and is a made a gate-on immediately before. From the photomultiplier 11 only the echo signal of the sea bottom is outputted therefore and the sounding accuracy can be increased.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、航空機、船舶などから海面等にパルスレーザ
を照射し、そのエコーにより水深を遠隔測定するレーザ
測深装置に間する。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a laser sounding device that irradiates a sea surface with a pulsed laser from an aircraft, a ship, etc., and remotely measures water depth based on its echo.

(従来の技術) 従来のレーザ測深装置の構成の概略を説明する、第3図
は従来のレーザ測深装置の構成を示すブロック図である
。パルスレーザ装置1の出力ビーム2を送信光学系3を
通して海面に向けて照射する。照射されたレーザ光は海
面4、海水中および海底5で反射され、それぞれの反射
信号は、受信光学系6にて受信される。
(Prior Art) FIG. 3, which explains the outline of the configuration of a conventional laser sounding device, is a block diagram showing the configuration of the conventional laser sounding device. The output beam 2 of the pulsed laser device 1 is irradiated toward the sea surface through the transmission optical system 3. The irradiated laser beam is reflected by the sea surface 4, seawater, and the seabed 5, and each reflected signal is received by a receiving optical system 6.

パルスレーザ装置1には、例えばYAGレーザの基本波
(波長: 1.064μm)と、その高調波(波長: 
532nm)を使用し、受信光学系6を経たレーザ光は
ビームスプリッタ−7により基本波と高調波とに分離さ
れ、狭帯域の基本波パスフィルター8と狭帯域の高調波
パスフィルター9により背景光を除去し光電変換素子と
しての光電子増倍管10および同11にてそれぞれ反射
信号を検出する。
The pulse laser device 1 has, for example, a fundamental wave (wavelength: 1.064 μm) of a YAG laser and its harmonics (wavelength:
532 nm), the laser beam that has passed through the receiving optical system 6 is separated into a fundamental wave and harmonics by a beam splitter 7, and background light is separated by a narrow-band fundamental wave pass filter 8 and a narrow-band harmonic pass filter 9. is removed, and reflected signals are detected by photomultiplier tubes 10 and 11 as photoelectric conversion elements, respectively.

光電子増倍管11にはゲートのかけられるものを使用す
る。従来のレーザ測深装置は基本波のし−ザ光は、海水
中の吸収、散乱が大きく、海面反射光のみが受信され、
海底からの反射光は、高調波のレーザ光のみであること
を利用している。
A gated photomultiplier tube 11 is used. In conventional laser sounding devices, the fundamental wave laser light is highly absorbed and scattered in seawater, and only the light reflected from the sea surface is received.
It takes advantage of the fact that the only reflected light from the ocean floor is harmonic laser light.

すなわち光電子増倍管10では海面からの反射光を検出
する。光電子増倍管10の出力を増幅器12で増幅した
後、トリガ検出回路13へ加える、トリガ検出回路13
は高圧パルサー15ヘトリガバルスを出力し、高圧パル
サー15では適当な遅延時間をもたせ、光電子増倍管1
1を動作させるためのゲートパルスを出力する。また、
トリガ検出回路13の出力パルスを時間差検出回路16
のスタートパルスとして用いる。
That is, the photomultiplier tube 10 detects reflected light from the sea surface. A trigger detection circuit 13 that amplifies the output of the photomultiplier tube 10 with an amplifier 12 and then applies it to the trigger detection circuit 13.
outputs a trigger pulse to the high-pressure pulser 15, and the high-pressure pulser 15 has an appropriate delay time, and the photomultiplier tube 1
Outputs a gate pulse to operate 1. Also,
The output pulse of the trigger detection circuit 13 is detected by the time difference detection circuit 16.
Used as a start pulse.

海底からの反射光である高調波は、光電子増倍管11で
検出され、増幅器12で増幅されトリガ検出回路14へ
導びかれてトリガパルスを出力する。このパルス出力は
時間差検出回路16へ加えられストップパルスとして作
用する。結局海面からの反射光によるパルスをスタート
パルスとし海底からの反射光によるパルスをストップパ
ルスとしているので時間差検出回路16の出力から水深
が得られることになる。
Harmonic waves, which are light reflected from the seabed, are detected by a photomultiplier tube 11, amplified by an amplifier 12, and guided to a trigger detection circuit 14 to output a trigger pulse. This pulse output is applied to the time difference detection circuit 16 and acts as a stop pulse. After all, since the pulse of light reflected from the sea surface is used as a start pulse and the pulse of light reflected from the seabed is used as a stop pulse, the water depth can be obtained from the output of the time difference detection circuit 16.

このような装置で得られる反射(エコー)信号の一例を
第4図に示す。第4図(a)は光電子増倍管10で検出
される海面からの反射信号であり、第4図(b)は光電
子増倍管11で検出される海面および海底からの反射信
号である。
An example of a reflected (echo) signal obtained with such a device is shown in FIG. FIG. 4(a) shows the reflected signal from the sea surface detected by the photomultiplier tube 10, and FIG. 4(b) shows the reflected signal from the sea surface and the seabed detected by the photomultiplier tube 11.

第4図(b)において、パルスレーザ装置1より送り出
されたレーザ光は、大気で減衰を受け、その一部を後方
散乱しながらくイ部に対応)S面に達し約2%の光は海
面で反射される(口部に対応)、残りの海面下に入射し
た光は、海中で減衰を受け、その一部を後方散乱しなが
ら(へ部に対応)海底に達し、海底で反射される(二部
に対応)、そして背景光雑音レベル(ホ部に対応)に落
ちつく、このようなエコー信号の口部およびニーの立上
がり時刻差を求めれば水深が測定できる。
In Fig. 4(b), the laser beam emitted from the pulsed laser device 1 is attenuated in the atmosphere, and a part of it is backscattered when it reaches the S plane (corresponding to the hollow part), and about 2% of the light is transmitted to the sea surface. The rest of the light incident below the sea surface is attenuated in the sea, and some of it is scattered back (corresponding to the bottom), reaching the sea floor, where it is reflected. (corresponding to the second part) and the background light noise level (corresponding to the ho part), and the water depth can be measured by finding the difference in the rise times of the mouth and knee of such echo signals.

ここで、光電子増倍管11にて検出すべき高調波の海面
からのエコー信号と海底からのエコー信号のレベル差が
問題となる。実用上必要とされる測定深度1〜30mと
海水の透明度とを考慮すると、レーザ光は海水中の吸収
、散乱により減衰し、海底からのエコー信号は非常に低
い、従って光電子増倍管には高いバイアス電圧を印加し
、微弱光検出が可能な状態にして使用しなければならな
い、一方海面からのエコー信号は、海底からのエコー信
号と比較して少なくとも105倍以上高いレベルを示す
Here, the level difference between the harmonic echo signal from the sea surface and the echo signal from the seabed to be detected by the photomultiplier tube 11 becomes a problem. Considering the practically required measurement depth of 1 to 30 m and the transparency of seawater, the laser beam is attenuated by absorption and scattering in the seawater, and the echo signal from the seafloor is very low. It must be used by applying a high bias voltage and enabling weak light detection, while the echo signal from the sea surface exhibits a level at least 105 times higher than the echo signal from the ocean floor.

従って海底からの微弱光の数十ナノ秒〜数百ナノ秒前に
光電子増倍管11の光電面にそのダイナミックレンジを
越える強力な光が入射されることになる。
Therefore, intense light exceeding the dynamic range of the photomultiplier tube 11 is incident on the photocathode of the photomultiplier tube 11 several tens to hundreds of nanoseconds before the weak light from the ocean floor.

(発明が解決しようとする問題点) 上述した従来のレーザ測深装置においては、微弱光を検
出するための光電子増倍管に、桁違いの強力な光も入射
される。高速にゲート動作させるために、あらかじめ光
電陰極にバイアス電圧を印・加させておき、陽極との中
間電極に低電圧パルスを印加しゲートのオンオフをさせ
る。
(Problems to be Solved by the Invention) In the conventional laser sounding device described above, extremely powerful light is also incident on the photomultiplier tube for detecting weak light. In order to operate the gate at high speed, a bias voltage is applied to the photocathode in advance, and a low voltage pulse is applied to the intermediate electrode between it and the anode to turn the gate on and off.

従って、強力な光入射により多大な量の光電子・が放出
された後、数十ナノ秒後に微弱光が入力ぎ・れた場合、
微弱光は、充分に光電変換されない為に、海底からのエ
コー信号が受信される瞬間にゲートオンし寸も、検出能
力が低いという欠点がある。
Therefore, if a large amount of photoelectrons are emitted due to strong light incidence, and then weak light is input several tens of nanoseconds later,
Since weak light is not sufficiently photoelectrically converted, it has the disadvantage that the gate is turned on at the moment an echo signal from the ocean floor is received, and its detection ability is low.

本発明の目的は、海面等の水面および水面に近い水中か
らの強力な反射光があっても海底等の水底からの微弱な
反射光が充分に光電変換され検出されるレーザ測深装置
を提供することにある。
An object of the present invention is to provide a laser sounding device in which even if there is strong reflected light from a water surface such as the sea surface or underwater near the water surface, weak reflected light from the bottom of the water such as the seabed is sufficiently photoelectrically converted and detected. There is a particular thing.

(問題点を解決するための手段) 本発明のレーザ測深装置は、上記の目的を達成するため
に次の構成を有する。
(Means for Solving the Problems) The laser sounding device of the present invention has the following configuration in order to achieve the above object.

レーザ光源からのレーザビームを水面に照射し、水面お
よび水底からのそれぞれのレーザ反射光を光電子増倍管
を用いた光電変換装置で受光し、両反射光の立上り時間
差から水深を測定するレーザ測深装置において、ゲート
パルス信号を受けて光電子増倍管へのレーザ光入射を阻
止する光シャッター装置と、該光シャッター装置へ所定
の幅のゲートパルスを送出するゲートパルス発生器と、
該ゲートパルス発生のタイミングを水面からの反射光が
到達するタイミングに設定するタイミング設定手段とを
有する。
Laser bathymetry: irradiates the water surface with a laser beam from a laser light source, receives each laser reflected light from the water surface and the water bottom with a photoelectric conversion device using a photomultiplier tube, and measures the water depth from the difference in rise time of both reflected lights. The apparatus includes: an optical shutter device that receives a gate pulse signal and blocks laser light from entering the photomultiplier tube; a gate pulse generator that sends a gate pulse of a predetermined width to the optical shutter device;
and timing setting means for setting the timing of the gate pulse generation to the timing at which the reflected light from the water surface arrives.

(作用) 本発明のレーザ測深装置は以上の構成を有するから、水
面や水面に近い水中から強力なレーザ光が反射されてレ
ーザ測深装置に到達しても、その到達のタイミングに合
わせて、タイミング設定手段からの信号によりゲートパ
ルス発生器がゲートパルスを発生し、このゲートパルス
が光シャッター装置へ加えられて、光シャッター装置は
ゲートパルスの幅に相当する時間レーザ光の通過を阻止
する。そしてこのゲートパルスの幅は水面および水中か
らの強力な反射光の通過は阻止するが、強力な反射光よ
り時間的に後に到達する水底からの微弱な反射光の通過
は阻止しないような幅に設定される。従って、水面や水
中から反射されて来た強力なレーザ光は光電子増倍管に
入射しない。
(Function) Since the laser sounding device of the present invention has the above configuration, even if a strong laser beam is reflected from the water surface or underwater near the water surface and reaches the laser sounding device, the timing can be adjusted according to the timing of the arrival. A gate pulse generator generates a gate pulse in response to a signal from the setting means, and this gate pulse is applied to the optical shutter device, so that the optical shutter device blocks passage of the laser beam for a time corresponding to the width of the gate pulse. The width of this gate pulse is set to a width that blocks the passage of strong reflected light from the water surface and water, but does not block the passage of weak reflected light from the water bottom that arrives later than the strong reflected light. Set. Therefore, powerful laser light reflected from the water surface or underwater does not enter the photomultiplier tube.

このため、従来のレーザ測深装置におけるような、水面
からの強力な反射光のために光電子増倍管で多量の光電
子放射が行われ、その後に続く水底からの微弱な反射光
の光電変換が充分性われず反射光の検出能力が低下する
という問題がなくなる。
For this reason, as in conventional laser sounding devices, a large amount of photoelectron emission is performed by a photomultiplier tube due to the strong reflected light from the water surface, and the subsequent photoelectric conversion of the weak reflected light from the water bottom is sufficient. This eliminates the problem that the ability to detect reflected light decreases without any effect.

(実施例) 以下本発明にがかるレーザ測深装置の実施例を図面に基
づいて説明する。
(Example) Hereinafter, an example of a laser sounding device according to the present invention will be described based on the drawings.

第1図は本発明の一実施例を示す構成図であり、第2図
は、各部の波形図であり記号A、B、C等は第1図中の
同一記号を付した点の波形であることを示す、17は反
射鏡、18は干渉フィルタ、19は偏光子、20は検光
子、21は光シヤツタ素子、22は光シヤツタ素子用の
高圧パルサー、23は海面までの高度を測定する時間差
測定回路、24は遅延時間設定回路、25は自動バイア
ス設定回路、26は光検出素子である。
FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG. 2 is a waveform diagram of each part. Symbols A, B, C, etc. are the waveforms of points with the same symbols in FIG. 1. 17 is a reflecting mirror, 18 is an interference filter, 19 is a polarizer, 20 is an analyzer, 21 is an optical shutter element, 22 is a high-pressure pulsar for the optical shutter element, and 23 measures the altitude to the sea surface. 24 is a delay time setting circuit, 25 is an automatic bias setting circuit, and 26 is a photodetection element.

なお、その他の構成要素で、第3図の従来例と同一機能
を有するものについては同一の符号を付してその説明を
省略する。
It should be noted that other components having the same functions as those of the conventional example shown in FIG. 3 are given the same reference numerals and their explanations will be omitted.

パルスレーザ装置1には、繰り返し周波数30〜400
H2、波長500nm前後の、例えば、色素レーザ又は
YAGレーザの高調波を用いる。
The pulse laser device 1 has a repetition frequency of 30 to 400.
H2, a harmonic of a dye laser or a YAG laser with a wavelength of around 500 nm, for example, is used.

海面および海底からの反射エコー信号は、反射鏡17、
干渉フィルター18、偏光子19、光シヤツタ素子21
、検光子20を通って光電子増倍管11に入射する(第
2図B−a参照)。
The reflected echo signals from the sea surface and the seabed are reflected by a reflector 17,
Interference filter 18, polarizer 19, optical shutter element 21
, passes through the analyzer 20 and enters the photomultiplier tube 11 (see FIG. 2 B-a).

偏光子19と検光子20の関係は、偏光子19を通った
偏光成分の光ビームが検光子20を通過するようにして
おく。光検出素子26は、パルスレーザ装置1のパルス
出力の1部を検出し、その出力パルス(第2図A −a
 )は時間差測定回路23に導びかれる。海面からの反
射エコー信号もまた時間差測定回路23に導びかれ(第
2図C−a)、レーザ出力パルスと海面からの反射エコ
ー信号との時間差を測定し、その時間差を遅延時間設定
回路24にて設定する。
The relationship between the polarizer 19 and the analyzer 20 is such that the light beam of the polarized component that has passed through the polarizer 19 passes through the analyzer 20. The photodetector element 26 detects a part of the pulse output of the pulse laser device 1, and detects the output pulse (Fig. 2A-a).
) is led to the time difference measuring circuit 23. The reflected echo signal from the sea surface is also guided to the time difference measuring circuit 23 (FIG. 2 C-a), which measures the time difference between the laser output pulse and the reflected echo signal from the sea surface, and the time difference is input to the delay time setting circuit 24. Set in .

この時間差測定回路23と遅延時間設定回路24とでタ
イミング設定手段を構成する。そして、次の光検出素子
26の出力パルス(第2図A−b〉を検出し遅延時間設
定回路24から設定遅延時間後に高圧パルサー15およ
び同22ヘトリガーパルス出力(第2図りおよびE)を
送り、光電子増倍管11および光シャ1.タ素子21を
動作させるためのゲートパルス(第2図FおよびG)を
出力する。ここで遅延時間設定回路24は、海面からの
反射エコー信号が立上がる前に光シヤツタ素子21のゲ
ートパルスが立上がるようにしておく、また高圧パルサ
ー22のゲートパルス幅は、海面および海中からの強力
な反射エコーの時間幅になるようにしておく。光シヤツ
タ素子21に所定電圧のゲートパルス(第2図F)を印
加するとその間、光シャッター素子21からの出射ビー
ムは検光子20と直交した偏光軸となり、検光子により
阻止される。従って海面からの反射エコーは減衰され、
わずかなもれ光だけが光電子増倍管11に入射されるこ
とになる(第2図B−b)。
The time difference measuring circuit 23 and the delay time setting circuit 24 constitute timing setting means. Then, the next output pulse of the photodetecting element 26 (A-b in Fig. 2) is detected, and the delay time setting circuit 24 outputs the trigger pulse (see Fig. 2 and E) to the high-voltage pulser 15 and 22 after the set delay time. The gate pulse (FIG. 2 F and G) for operating the photomultiplier tube 11 and optical shutter element 21 is outputted. The gate pulse of the optical shutter element 21 is made to rise before the rise, and the gate pulse width of the high-voltage pulser 22 is made to be the time width of the strong reflected echo from the sea surface and underwater. When a gate pulse of a predetermined voltage (FIG. 2 F) is applied to the element 21, during that time the beam emitted from the optical shutter element 21 has a polarization axis perpendicular to the analyzer 20 and is blocked by the analyzer. the echo is attenuated,
Only a small amount of leaked light will be incident on the photomultiplier tube 11 (FIG. 2B-b).

従って、光電子増倍管11への強力なレーザ光入射がな
くなるので多量の光電子放出ということがなくなり海底
からの微弱な光信号に対して充分な光電変換が行われる
。一方海底からの反射エコーが到達した時は光シャッタ
ー素子21へのゲ−トパルスがオフになっているので、
そのまま、検光子20を通過し、光電子増倍管11に入
射される。光電子増倍管11は、海底からのエコーが到
達するまでゲートオフの状態にしておき、直前にゲート
オンにする。従って、光電子増倍管11からは、海底か
らのエコー信号のみ出力される(第2図c−b)、自動
バイアス設定回路25は、光電子増倍管11の出力信号
レベルにより光電子増倍管11へのバイアス電圧を自動
設定するための、ものであり、海面からの反射光検出時
には低電圧を、海底からの反射光検出時には高電圧を光
電子増倍管に印加する。
Therefore, since strong laser light is not incident on the photomultiplier tube 11, a large amount of photoelectrons are not emitted, and sufficient photoelectric conversion is performed on weak optical signals from the ocean floor. On the other hand, when the reflected echo from the ocean floor arrives, the gate pulse to the optical shutter element 21 is turned off, so
The light passes through the analyzer 20 as it is and enters the photomultiplier tube 11. The photomultiplier tube 11 is kept gated off until the echo from the ocean floor arrives, and then turned on immediately before. Therefore, only the echo signal from the ocean floor is output from the photomultiplier tube 11 (FIG. 2 c-b). A low voltage is applied to the photomultiplier tube when detecting reflected light from the sea surface, and a high voltage is applied to the photomultiplier tube when detecting reflected light from the ocean floor.

こうして得られた光電子増倍管の出力は増幅器12で増
幅された後トリガ検出回路14へ加えられ、ここで海底
からのエコー信号に対応するトリガが検出される。この
トリガ信号は時間差検出回路16へ加えられる0時間差
検出回路16へは、時間差測定回路23から海面からの
エコー信号に対応するパルス信号も加えられ、このパル
ス信号をスタートパルスとし、トリガ検出回路14から
のトリガ信号をストップパルスとして時間差を検出し深
度を測定する。
The output of the photomultiplier tube thus obtained is amplified by an amplifier 12 and then applied to a trigger detection circuit 14, where a trigger corresponding to an echo signal from the ocean floor is detected. This trigger signal is applied to the time difference detection circuit 16.A pulse signal corresponding to the echo signal from the sea surface is also applied to the time difference detection circuit 16 from the time difference measurement circuit 23. This pulse signal is used as a start pulse, and the trigger detection circuit 14 The depth is measured by detecting the time difference using the trigger signal from the stop pulse as a stop pulse.

(発明の効果) 本発明のレーザ測深装置は、以上説明したように、ゲー
トパルス信号を受けて光電子増倍管へのレーザ光入射を
阻止する光シャッター装置と、該光シャッター装置へ所
定の幅のゲートパルスを送出するゲートパルス発生器と
、該ゲートパルス発生のタイミングを水面からの反射光
が到達するタイミングに設定するタイミング設定手段と
を有しており、水面や水面に近い水中から強力なレーザ
光が反射されてレーザ測深装置に到達しても、その到達
のタイミングに合わせて、タイミング設定手段からの信
号によりゲートパルス発生器がゲートパルスを発生し、
このゲートパルスが光シャッター装置へ加えられて、光
シャッター装置はゲートパルスの幅に相当する時間レー
ザ光の通過を阻止する。そしてこのゲートパルスの幅は
水面および水中からの強力な反射光の通過は阻止するが
、強力な反射光より時間的に後に到達する水底からの微
弱な反射光の通過は阻止しないような幅に設定される。
(Effects of the Invention) As explained above, the laser sounding device of the present invention includes an optical shutter device that receives a gate pulse signal and blocks laser light from entering a photomultiplier tube, and a predetermined width of the optical shutter device. It has a gate pulse generator that sends out a gate pulse, and a timing setting means that sets the timing of generating the gate pulse to the timing when reflected light from the water surface arrives. Even when the laser beam is reflected and reaches the laser sounding device, the gate pulse generator generates a gate pulse according to the signal from the timing setting means in accordance with the timing of the arrival.
This gate pulse is applied to the optical shutter device, which blocks the passage of the laser light for a time corresponding to the width of the gate pulse. The width of this gate pulse is set to a width that blocks the passage of strong reflected light from the water surface and water, but does not block the passage of weak reflected light from the water bottom that arrives later than the strong reflected light. Set.

従って、水面や水中から反射されて来た強力なレーザ光
は光電子増倍管に入射しない。
Therefore, powerful laser light reflected from the water surface or underwater does not enter the photomultiplier tube.

このため、従来のレーザ測深装置におけるような、水面
からの強力な反射光のために光電子増倍管で多量の光電
子放射が行われ、その後に続く水底からの微弱な反射光
の光電変換が充分行われず反射光の検出能力が低下する
という問題がなくなる。その結果、本発明を適用すれば
、海底などからの微弱な反射光の検出能力を向上した測
深精度の高いレーザ測深装置を実現できるという利点が
ある。
For this reason, as in conventional laser sounding devices, a large amount of photoelectron emission is performed by a photomultiplier tube due to the strong reflected light from the water surface, and the subsequent photoelectric conversion of the weak reflected light from the water bottom is sufficient. This eliminates the problem that the ability to detect reflected light is degraded due to failure to do so. As a result, by applying the present invention, there is an advantage that a laser sounding device with high sounding accuracy and improved ability to detect weak reflected light from the seabed or the like can be realized.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の実施例の構成を示すブロック図、第2
図は、第1図の構成における各部の信号波形を示す図、
第3図は従来のレーザ測深装置の構成を示すブロック図
、第4図は従来のレーザ測深装置の信号波形図である。 1・・・・・・パルスレーザ装置、 2・・・・・・出
力ビーム3・・・・・・送信光学系、 4・・・・・・
海面5・・・・・・海底、 6・・・・・・受信光学系
、 7・・・・・・ビームスプリッタ−18・・・・・
・基本波パスフィルター、 9・・・・パ・高調波バス
フィルター、 10.11・・・・・・光電子増倍管、
 12・・・・・・増幅器、13.14・・・・・・ト
リガ検出回路、 15・・・・・・高圧パルサー、 1
6・・・・・・時間差検出回路、 17・・・・・・反
射鏡、 18・・・・・・干渉フィルタ、  19・・
・・・・偏光子、 20・・・・・・検光子、 21・
・・・・・光シヤツタ素子、 22・・・・・・高圧パ
ルサー、 23・・・・・・時間差測定回路、 24・
・・・・・遅延時間設定回路、25・・・・・・自動バ
イアス設定回路、 26・・・・・・光検出素子。 代理人 弁理士  八 幡  義 博 ab 突施倒1ζわ゛ける各()の1形 第2図 (a) 口 (b) 従夫のレーサ゛湧H灼えXの信号麦形図j64図
FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure shows the signal waveform of each part in the configuration of FIG.
FIG. 3 is a block diagram showing the configuration of a conventional laser sounding device, and FIG. 4 is a signal waveform diagram of the conventional laser sounding device. 1...Pulse laser device, 2...Output beam 3...Transmission optical system, 4...
Sea surface 5... Seabed, 6... Receiving optical system, 7... Beam splitter 18...
・Fundamental wave pass filter, 9...Pharmonic bass filter, 10.11...Photomultiplier tube,
12...Amplifier, 13.14...Trigger detection circuit, 15...High voltage pulser, 1
6...Time difference detection circuit, 17...Reflector, 18...Interference filter, 19...
...Polarizer, 20...Analyzer, 21.
..... optical shutter element, 22 ..... high voltage pulsar, 23 ..... time difference measurement circuit, 24.
... Delay time setting circuit, 25 ... Automatic bias setting circuit, 26 ... Photo detection element. Agent Patent Attorney Yoshihiro Yahata AB Sudden Overturning 1ζ Wails Each () 1 Form 2 (a) Mouth (b) Signal Wheat Shape Diagram J64 of the Cousin's Racer

Claims (1)

【特許請求の範囲】[Claims] レーザ光源からのレーザビームを水面に照射し、水面お
よび水底からのそれぞれのレーザ反射光を光電子増倍管
を用いた光電変換装置で受光し、両反射光の立上り時間
差から水深を測定するレーザ測深装置において、ゲート
パルス信号を受けて光電子増倍管へのレーザ光入射を阻
止する光シャッター装置と、該光シャッター装置へ所定
の幅のゲートパルスを送出するゲートパルス発生器と、
該ゲートパルス発生のタイミングを水面からの反射光が
到達するタイミングに設定するタイミング設定手段とを
有することを特徴とするレーザ測深装置。
Laser bathymetry: irradiates the water surface with a laser beam from a laser light source, receives each laser reflected light from the water surface and the water bottom with a photoelectric conversion device using a photomultiplier tube, and measures the water depth from the difference in rise time of both reflected lights. The apparatus includes: an optical shutter device that receives a gate pulse signal and blocks laser light from entering the photomultiplier tube; a gate pulse generator that sends a gate pulse of a predetermined width to the optical shutter device;
1. A laser sounding device comprising: timing setting means for setting the timing of generating the gate pulse to the timing at which reflected light from the water surface arrives.
JP14849585A 1985-07-06 1985-07-06 Laser sounding device Granted JPS629284A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14849585A JPS629284A (en) 1985-07-06 1985-07-06 Laser sounding device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14849585A JPS629284A (en) 1985-07-06 1985-07-06 Laser sounding device

Publications (2)

Publication Number Publication Date
JPS629284A true JPS629284A (en) 1987-01-17
JPH0564750B2 JPH0564750B2 (en) 1993-09-16

Family

ID=15454026

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14849585A Granted JPS629284A (en) 1985-07-06 1985-07-06 Laser sounding device

Country Status (1)

Country Link
JP (1) JPS629284A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04330106A (en) * 1991-04-30 1992-11-18 Niigata Eng Co Ltd Paving thickness controlling method for grader
JP2008039837A (en) * 2006-08-01 2008-02-21 Toppan Forms Co Ltd Label
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JP2014190934A (en) * 2013-03-28 2014-10-06 Mitsubishi Electric Corp Tsunami detection system
JP2015230180A (en) * 2014-06-03 2015-12-21 株式会社パスコ River topography measurable region determination device, river topography measurable region determination method, and river topography measurable region determination program
JP2016540198A (en) * 2013-10-23 2016-12-22 レーダー リミテッドLadar Limited Laser detection and ranging device for detecting objects under water
WO2018168564A1 (en) * 2017-03-12 2018-09-20 株式会社ナイルワークス Drone for measuring water depth of field
JP2019158523A (en) * 2018-03-12 2019-09-19 株式会社デンソー Distance measuring device and distance measuring method
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Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04330106A (en) * 1991-04-30 1992-11-18 Niigata Eng Co Ltd Paving thickness controlling method for grader
JP2008039837A (en) * 2006-08-01 2008-02-21 Toppan Forms Co Ltd Label
JP2010216904A (en) * 2009-03-16 2010-09-30 National Maritime Research Institute Object detection method and lidar device, and environment measuring method
JP2014190934A (en) * 2013-03-28 2014-10-06 Mitsubishi Electric Corp Tsunami detection system
US10175356B2 (en) 2013-10-23 2019-01-08 Ladar Limited Laser detection and ranging device for detecting an object under a water surface
US11467269B2 (en) 2013-10-23 2022-10-11 Ladar Limited Laser detection and ranging device for detecting an object under a water surface
JP2016540198A (en) * 2013-10-23 2016-12-22 レーダー リミテッドLadar Limited Laser detection and ranging device for detecting objects under water
JP2019219414A (en) * 2013-10-23 2019-12-26 レーダー リミテッドLadar Limited Laser detection and ranging device for detecting object under water surface
JP2014139576A (en) * 2014-03-06 2014-07-31 National Maritime Research Institute Object detection method, lidar device, and environment measuring method
JP2015230180A (en) * 2014-06-03 2015-12-21 株式会社パスコ River topography measurable region determination device, river topography measurable region determination method, and river topography measurable region determination program
WO2018168564A1 (en) * 2017-03-12 2018-09-20 株式会社ナイルワークス Drone for measuring water depth of field
JPWO2018168564A1 (en) * 2017-03-12 2020-01-09 株式会社ナイルワークス Drone for measuring water depth in the field
JP2019158523A (en) * 2018-03-12 2019-09-19 株式会社デンソー Distance measuring device and distance measuring method
CN116609759A (en) * 2023-07-21 2023-08-18 自然资源部第一海洋研究所 Method and system for enhancing and identifying airborne laser sounding seabed weak echo
CN116609759B (en) * 2023-07-21 2023-10-31 自然资源部第一海洋研究所 Method and system for enhancing and identifying airborne laser sounding seabed weak echo

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