JPH02110313A - Detection of target position by use of camera - Google Patents
Detection of target position by use of cameraInfo
- Publication number
- JPH02110313A JPH02110313A JP63262745A JP26274588A JPH02110313A JP H02110313 A JPH02110313 A JP H02110313A JP 63262745 A JP63262745 A JP 63262745A JP 26274588 A JP26274588 A JP 26274588A JP H02110313 A JPH02110313 A JP H02110313A
- Authority
- JP
- Japan
- Prior art keywords
- target
- camera
- angle
- image
- field
- 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
Links
- 238000001514 detection method Methods 0.000 title abstract description 4
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000004364 calculation method Methods 0.000 claims description 11
- 230000000007 visual effect Effects 0.000 abstract description 5
- 238000004904 shortening Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 11
- 238000009434 installation Methods 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Landscapes
- Length Measuring Devices By Optical Means (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は例えば陸上の高所に設置されたカメラによる
海上を航行する船舶等の物標の位置検出方法、特にカメ
ラから物標をみた角度が俯角となる場合のカメラによる
物標位置の検出方法に関するものである。[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for detecting the position of a target object such as a ship sailing on the sea using a camera installed at a high place on land, and in particular, a method for detecting the position of a target object such as a ship sailing on the sea using a camera installed at a high place on land, and in particular, a method for detecting the position of a target object such as a ship sailing on the sea. The present invention relates to a method for detecting the position of a target object using a camera when the angle of depression is the angle of depression.
［従来の技術］
従来カメラによる物標の位置検出は、三角測量による方
法が多かった。三角測量は周知のように、その間隔が既
知である２地点で得られる物標の方位をｉ１Ｍ定し、そ
の距離算出により物標の位置を求めるものであった。[Prior Art] Conventionally, the position of a target object using a camera has often been detected by triangulation. As is well known, triangulation involves determining the direction of a target object obtained from two points whose distance is known, and determining the position of the target object by calculating the distance.
第２図は従来の三角測量を説明する図であり、Ａ、Ｂは
その間隔が既知の２地点、Ｃは物標の位置である。いま
Ａ点とＢ点との距離をｄ、Ａ点とＢ点を直線で結ぶ方位
を基準方位として、Ａ点から０点への方位が基準方位と
の間になす角度をα、Ｂ点から０点への方位が基準方位
との間になす角度をβ、Ｂ点から０点への距離をＲとし
、特にβ−９０”の場合はｔａｎα−Ｒ／ｄとなること
を利用し、Ｒ−ｄ’ｔａｎαが求められる。従って物標
Ｃの位置は基準点Ａ、Ｂからの方位（即ち基準方位に対
する角度）及び距離の両データにより検出される。FIG. 2 is a diagram explaining conventional triangulation, where A and B are two points whose distance is known, and C is the position of a target. Now, the distance between points A and B is d, and the direction connecting points A and B with a straight line is the reference direction, and the angle that the direction from point A to point 0 makes with the reference direction is α, from point B. The angle between the direction to the 0 point and the reference direction is β, the distance from the B point to the 0 point is R, and in particular, in the case of β-90”, using the fact that tanα-R/d, R -d'tanα is determined. Therefore, the position of the target C is detected from both the azimuth (that is, the angle with respect to the reference azimuth) and distance data from the reference points A and B.
［発明が解決しようとする課題］
上記のような従来のカメラによる物標の位置検出方法は
、その間隔が既知である異なる位置にそれぞれ設置され
た２台のカメラから得られる方位信号に基づき物標の位
置を算出する方法であるため、１台のカメラ映像から物
標の位置を得ることができないという問題点があった。[Problems to be Solved by the Invention] The conventional method for detecting the position of a target object using a camera as described above detects the position of a target object based on azimuth signals obtained from two cameras installed at different positions with a known distance between them. Since this method calculates the position of a target, there is a problem in that the position of the target cannot be obtained from a single camera image.
この発明はかかる問題点を解決するためになされたもの
で、１台のカメラ映像から物標の位置を検出する方法を
得ることを目的とする。The present invention was made to solve this problem, and an object of the present invention is to provide a method for detecting the position of a target object from an image of a single camera.
［課題を解決するための手段］
この発明に係るカメラによる物標位置の検出方法は、カ
メラの視野中心軸を水平に保持し、その視野内の物標を
みた角度が俯角となるような位置に設置された前記カメ
ラの位置、高さ、視野の中心方位及び視野角、並びに視
野内の映像の平面画像及び該平面画像上での前記物標の
座標位置についてのそれぞれの情報をカメラ関連情報入
力手段により入力し、前記カメラから物標をみた俯角を
前記平面画像上での物標の座標位置とカメラの視野角と
により算出する方法により、物標位置算出手段が前記物
標の位置を算出し、前記物標位置算出手段が算出した物
標の位置を物標位置出力手段が出力するものである。[Means for Solving the Problems] A method for detecting a target position using a camera according to the present invention is to maintain the central axis of the field of view of the camera horizontally, and to detect a position at which the angle at which the target object within the field of view is viewed is the angle of depression. Camera-related information includes information about the position, height, central direction of the field of view, and viewing angle of the camera installed in The target position calculating means calculates the position of the target by inputting the input using the input means and calculating the angle of depression when viewing the target from the camera based on the coordinate position of the target on the planar image and the viewing angle of the camera. The target position output means outputs the position of the target calculated by the target position calculation means.
［作 用］
この発明においては、例えば陸上の高所に設置されたカ
メラによる海上を航行する船舶等の物標の位置検出方法
として、海面上から既知の高さの位置にカメラを、その
視野中心軸を水平に保持し、方位方向のみ自由に可動す
るように設置し、カメラから指示された物標をみた時の
俯角とカメラの視野角の比が、カメラで撮影した平面画
像上での視野中心軸位置から物標位置までの距離と視野
中心軸位置から視野限界位置までの距離の比にほぼ近似
する関係を用いて前記カメラから物標をみた俯角を算出
し、前記既知のカメラの海面上からの高さと算出された
俯角とにより三角測量の原理を用い物標迄の距離を算出
する。また別にカメラから物標をみた方位を別の方位セ
ンサで検出し、前記物標の方位及び距離データを出力す
ることにより物標位置の検出及び出力をするものである
。[Function] In this invention, for example, as a method for detecting the position of a target such as a ship sailing on the sea using a camera installed at a high place on land, the camera is placed at a known height above the sea surface, and its field of view is The central axis is held horizontally, and the camera is installed so that it can move freely only in the azimuth direction, and the ratio of the angle of depression when looking at the target indicated by the camera to the viewing angle of the camera is determined on the plane image taken by the camera. The angle of depression when viewing the target from the camera is calculated using a relationship that approximately approximates the ratio of the distance from the visual field center axis position to the target object position and the distance from the visual field center axis position to the visual field limit position, and the depression angle when the target object is viewed from the camera is calculated. The distance to the target is calculated using the principle of triangulation based on the height above sea level and the calculated angle of depression. In addition, the azimuth of the target viewed from the camera is detected by another azimuth sensor, and the azimuth and distance data of the target are output, thereby detecting and outputting the target position.
［実施例］
第１図は本発明に係るカメラによる物標位置検出手段の
ブロック図であり、１にカメラ関連情報入力手段、２は
物標位置算出手段、３は物標位置出力手段である。[Example] Fig. 1 is a block diagram of a target position detection means using a camera according to the present invention, in which 1 is a camera-related information input means, 2 is a target position calculation means, and 3 is a target position output means. .
第１図の説明を行なう。カメラ関連情報入力手段１は、
例えばビデオカメラ装置及び画像指示器とにより構成さ
れ、物標が俯角をもって撮影されるように例えば山頂に
設置したカメラの設置位置（平面位置及び海面から設置
場所までの高さ）情報、該カメラの視野中心軸の方位情
報、該カメラの光学系により決まる視野角情報、該カメ
ラ視野内の映像の平面画像情報及び該平面画像上におい
て指示された物標の位置情報を入力するものである。物
標の位置情報については、ビデオカメラ装置により撮影
された平面画像情報が画像指示器に指示されたとき、手
動で物標を捕捉する（画面上に捕捉マークを移動させて
物標の位置と一致させる）ことにより、物標の座標位置
情報を検出し入力することができる。またカメラの視野
中心軸の方位情報はカメラに方位センサ（例えばシンク
ロ、レゾルバ、ロークリエンコーダ等）を設けて、該方
位センサからの出力信号を入力すればよい。カメラ関連
情報人力手段１に接続された物標位置算出手段２は、ビ
デオカメラ装置から入力した情報と、画像指示器から上
記画面上における物標映像を捕捉又は指示して得られた
物標の座標位置情報に基づき、上記カメラと物標の位置
関係と、上記画面内における物標の位置関係が対応して
決まることを利用して、指示した物標の位置を算出する
ものである。従って物標位置算出手段２は演算装置（例
えばマイクロプロセッサを含む演算装置等）により構成
される。物標位置算出手段２に接続される物標位置出力
手段３は、例えばデータ表示器により構成され、物標位
置算出手段２により算出された物標の位置を、例えば画
像情報と数値デー夕により表示するものである。なおビ
デオカメラ装置は夜間に使用する場合は赤外線方式の装
置が使用できる。画像指示器としてはラスク方式又はラ
ディアル方式（一般にＰＰＩという）の指示器が、また
データ表示器としてはグラフィックデイスプレィ又はキ
ャラクタデイスプレィがそれぞれ使用可能である。これ
らの装置については一般に周知であるので各装置の詳細
説明は省略する。FIG. 1 will be explained. Camera-related information input means 1 includes:
For example, it is composed of a video camera device and an image indicator, and information on the installation position (plane position and height from the sea surface to the installation place) of a camera installed on a mountaintop, for example, so that the target object is photographed with an angle of depression, Direction information about the center axis of the field of view, viewing angle information determined by the optical system of the camera, planar image information of the image within the camera's field of view, and position information of the target indicated on the planar image are input. Regarding the position information of the target, when the planar image information taken by the video camera device is instructed to the image indicator, the target is manually captured (by moving the capture mark on the screen to indicate the target's position). By matching the coordinate position information of the target object, it is possible to detect and input the coordinate position information of the target object. Further, the azimuth information of the center axis of the camera's field of view can be obtained by providing the camera with an azimuth sensor (for example, a synchronizer, a resolver, a low-resolution encoder, etc.) and inputting an output signal from the azimuth sensor. A target position calculation means 2 connected to the camera-related information manual means 1 uses information input from the video camera device and a target position obtained by capturing or instructing the target image on the screen from the image indicator. Based on the coordinate position information, the position of the designated target is calculated by utilizing the fact that the positional relationship between the camera and the target and the positional relationship of the target within the screen are determined in correspondence. Therefore, the target position calculation means 2 is constituted by an arithmetic device (for example, an arithmetic device including a microprocessor, etc.). The target position output means 3 connected to the target position calculation means 2 is constituted by, for example, a data display, and outputs the position of the target calculated by the target position calculation means 2 using, for example, image information and numerical data. It is to be displayed. Note that when using the video camera device at night, an infrared type device can be used. As the image indicator, a Rusk type or radial type (generally referred to as PPI) indicator can be used, and as the data display, a graphic display or a character display can be used. Since these devices are generally well known, detailed explanation of each device will be omitted.
第３図は本発明に係るカメラの視野と視野中心軸を説明
する図であり、同図（ａ）はカメラの設置場所及びその
視野を示す断面図である。図において、ＰＢはカメラの
設置位置、ｄはカメラの海面よりの高さ、ＰＡは高さｄ
を零とした場合（カメラを海面まで下げた場合）のカメ
ラ位置、αはカメラの光学レンズの中心軸に対する視野
角である。FIG. 3 is a diagram illustrating the field of view and central axis of the field of view of the camera according to the present invention, and FIG. 3(a) is a sectional view showing the installation location of the camera and its field of view. In the figure, PB is the camera installation position, d is the height of the camera above sea level, and PA is the height d.
The camera position when is set to zero (when the camera is lowered to the sea level), and α is the viewing angle with respect to the central axis of the camera's optical lens.
従ってカメラの視野は前記中心軸に対して角度αの円錐
形となる。またカメラの光学レンズの中心軸は常に水平
（即ち海面に対して平行）となるように上下方向には固
定され、方位（即ち左右方向）のみ変えられるものとす
る。同図（ｂ）はカメラ視野内の映像の平面画像で、そ
の視野範囲を円で示し、その中心Ｂ に十印を付したも
のである。The field of view of the camera is therefore conical at an angle α to the central axis. Further, it is assumed that the central axis of the optical lens of the camera is fixed in the vertical direction so that it is always horizontal (that is, parallel to the sea surface), and that only the direction (that is, the horizontal direction) can be changed. Figure (b) is a planar image of the image within the camera's field of view, with the field of view indicated by a circle and a cross marked at the center B.
第４図は本発明に係る海上の物標Ａの位置とその映像位
置を説明する図であり、同図（ａ）は海上の物標Ａへの
俯角と距離を示す断面図である。図において、Ａは海上
の物標、θはカメラより物標Ａへの俯角、Ｒは高さ零の
カメラ位置ＰＡから物標Ａまでの水平距離、Ｂは物標Ａ
より高さｄの上空の点である。また同図（ｂ）はカメラ
視野内の映像の平面画像で、その視野範囲を示す円と、
その内部に物標Ａの位置Ａ と、視野中心の位置Ｂ。FIG. 4 is a diagram illustrating the position of target A on the sea and its image position according to the present invention, and FIG. 4(a) is a sectional view showing the angle of depression and distance to target A on the sea. In the figure, A is a target on the sea, θ is the angle of depression from the camera to target A, R is the horizontal distance from the zero-height camera position PA to target A, and B is target A.
It is a point in the sky at a height d. Figure (b) is a planar image of the video within the camera's field of view, with a circle indicating the field of view,
Inside it is the position A of the target A and the position B of the center of the visual field.
に十印を付して示したものである。It is shown with a ten mark attached to it.
第５図は本発明に係る物標への俯角及び゛距離を説明す
る図であり、同図（ａ）は三角ΔＰｉを行なう場合の物
標Ａへの俯角及び距離を示し、同図（ｂ）は俯角を平面
画像上での物標位置より算出する方法を説明する図であ
る。FIG. 5 is a diagram for explaining the depression angle and distance to the target object according to the present invention; FIG. ) is a diagram illustrating a method of calculating the depression angle from the target position on a plane image.
いま第５図を用いて物標位置算出方法を説明する。同図
（ａ）において、カメラの海面よりの高さをｄ５カメラ
から物標Ａまでの水平距離をＲ、カメラから物標Ａをみ
た俯角をθとすると、三角測量の場合と同様に次の（１
） 、 （２）式の関係が成立する。The target position calculation method will now be explained using FIG. In the same figure (a), if the height of the camera above the sea level is d5, the horizontal distance from the camera to target A is R, and the angle of depression when looking at target A from the camera is θ, then as in the case of triangulation, the following (1
), the relationship of equation (2) holds true.
ｔａｎ θ−ｄ／Ｒ−（１）
Ｒ−ｄ／ｌａｎ θ −（２）
また同図（ｂ）のカメラ映像の平面画像上で、その視野
範囲を示す円の半径（即ち視野中心Ｂ より視野限界位
置Ｄ までの距離）をｇ１視野中心Ｂ より物標位置Ａ
までの距離をｍとすると近ＯＯ
似的に次の（３）式が成立する。tan θ-d/R-(1) R-d/lan θ-(2) Also, on the plane image of the camera image in Figure (b), the radius of the circle indicating the field of view range (i.e., the field of view from the center of field B) distance to limit position D) from g1 field of view center B to target position A
If the distance to is m, then the following equation (3) holds true.
θ中ｍ ／ ＩＩ ・α ・・・（３）従って（３）
式により算出された俯角θを（２）式に代入することに
よりカメラから物標Ａまでの水平距離Ｒが算出される。m in θ / II ・α ... (3) Therefore (3)
The horizontal distance R from the camera to the target object A is calculated by substituting the depression angle θ calculated by the formula into the formula (2).
また物標の方位はカメラに設けられた方位センサからの
方位信号をカメラ関連情報入力手段１より入力すること
により検出される。このようにして物標位置算出手段２
は物標の距離及び方位を算出し、物標位置出力手段３に
供給し、物標位置出力手段３はデータ表示器により、指
示された物標の位置を画像情報と数値データにより表示
する。Further, the direction of the target object is detected by inputting a direction signal from a direction sensor provided in the camera through the camera-related information input means 1. In this way, the target position calculation means 2
calculates the distance and direction of the target object and supplies them to the target position output means 3, which uses a data display to display the specified position of the target object using image information and numerical data.
［発明の効果］
以上のようにこの発明によれば、カメラから物標をみた
角度が俯角となるように海面よりの高さの既知の位置に
カメラを設置し、前記俯角をカメラ視野内の映像の平面
画像上の物標位置より算出し、物標位置を検出できるの
で、従来の三角／１−１量のように異なる場所に２台の
カメラを必要とせず、１台のカメラにより物標位置の検
出が可能となり、測定時間の短縮等の作業性向上の効果
が得られている。[Effects of the Invention] As described above, according to the present invention, a camera is installed at a known position at a height above the sea surface so that the angle at which the target is viewed from the camera is the angle of depression, and the angle of depression is determined within the field of view of the camera. Since the target position can be calculated and detected from the target position on the flat image of the video, there is no need for two cameras in different locations as in the conventional triangular/1-1 quantity, and the target position can be detected using one camera. It is now possible to detect target positions, resulting in improvements in work efficiency such as shortening measurement time.
第１図は本発明に係るカメラによる物標位置検出手段の
ブロック図、第２図は従来の三角測量を説明する図、第
３図は本発明に係るカメラの視野と視野中心軸を説明す
る図、第４図は本発明に係る海上の物標Ａの位置とその
映像位置を説明する図、第５図は本発明に係る物標への
俯角及び距離を説明する図である。
図において、１はカメラ関連情報入力手段、２は物標位
置算出手段、
３は物標位置出力手段であ
る。FIG. 1 is a block diagram of target position detection means using a camera according to the present invention, FIG. 2 is a diagram explaining conventional triangulation, and FIG. 3 is a diagram explaining the field of view and central axis of the field of view of the camera according to the present invention. 4 are diagrams for explaining the position of target A on the sea and its image position according to the present invention, and FIG. 5 is a diagram for explaining the depression angle and distance to the target according to the present invention. In the figure, 1 is camera-related information input means, 2 is target position calculation means, and 3 is target position output means.
Claims (1)
て、カメラの視野中心軸を水平に保持し、その視野内の
物標をみた、角度が俯角となるような位置に設置された
前記カメラの位置、高さ、視野の中心方位及び視野角、
並びに視野内の映像の平面画像及び該平面画像上での前
記物標の座標位置についてのそれぞれの情報をカメラ関
連情報入力手段により入力し、前記カメラから物標をみ
た俯角を前記平面画像上での物標の座標位置とカメラの
視野角とにより算出する方法により、物標位置算出手段
が前記物標の位置を算出し、前記物標位置算出手段が算
出した物標の位置を物標位置出力手段が出力することを
特徴とするカメラによる物標位置の検出方法。In a method for detecting the position of a target photographed by a camera, the central axis of the camera's field of view is held horizontally, and the camera is installed at a position such that the angle of the target within its field of view is an angle of depression. , height, central direction of view and viewing angle,
In addition, information about a planar image of the image within the field of view and the coordinate position of the target object on the planar image is inputted by the camera-related information input means, and the depression angle when the target object is viewed from the camera is displayed on the planar image. The target position calculation means calculates the position of the target by a method of calculating based on the coordinate position of the target and the viewing angle of the camera, and the position of the target calculated by the target position calculation means is used as the target position. A method for detecting a target position using a camera, characterized in that an output means outputs an output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63262745A JPH0739956B2 (en) | 1988-10-20 | 1988-10-20 | Method of detecting target position by camera |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63262745A JPH0739956B2 (en) | 1988-10-20 | 1988-10-20 | Method of detecting target position by camera |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02110313A true JPH02110313A (en) | 1990-04-23 |
| JPH0739956B2 JPH0739956B2 (en) | 1995-05-01 |
Family
ID=17379997
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63262745A Expired - Fee Related JPH0739956B2 (en) | 1988-10-20 | 1988-10-20 | Method of detecting target position by camera |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0739956B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104121892A (en) * | 2014-07-09 | 2014-10-29 | 深圳市欢创科技有限公司 | Method, device and system for acquiring light gun shooting target position |
| JP2020093640A (en) * | 2018-12-12 | 2020-06-18 | 西日本旅客鉄道株式会社 | Equipment position management system |
-
1988
- 1988-10-20 JP JP63262745A patent/JPH0739956B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104121892A (en) * | 2014-07-09 | 2014-10-29 | 深圳市欢创科技有限公司 | Method, device and system for acquiring light gun shooting target position |
| JP2020093640A (en) * | 2018-12-12 | 2020-06-18 | 西日本旅客鉄道株式会社 | Equipment position management system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0739956B2 (en) | 1995-05-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2667924B2 (en) | Aircraft docking guidance device | |
| US20120162360A1 (en) | Wide-Angle Image Pickup Unit And Measuring Device | |
| JP2002202126A (en) | Surveying apparatus and electronic storage medium | |
| CN208043364U (en) | A kind of crane girder Static stiffness detector | |
| JP2021039013A (en) | Wall crack measuring machine and measuring method | |
| JP2611173B2 (en) | Positioning method and device using fisheye lens | |
| WO2020070650A1 (en) | Optics based multi-dimensional target and multiple object detection and tracking method | |
| JPH0363795B2 (en) | ||
| JPH1019562A (en) | Surveying device and surveying method | |
| US4591987A (en) | Video rangefinder | |
| JPH11337322A (en) | Method for measuring appearance by two-dimensional image comparison, and device therefor | |
| JP3547946B2 (en) | Apron monitoring device | |
| JP7245757B2 (en) | Building side view creation system and building side view creation method | |
| CN119246524A (en) | A visual detection information acquisition device and method based on pitch angle calibration image | |
| JPH0739956B2 (en) | Method of detecting target position by camera | |
| JPS6256814A (en) | 3D position measurement camera calibration method | |
| JPH0617795B2 (en) | Three-dimensional position measuring device | |
| JPH0337513A (en) | Three-dimensional position/speed measuring apparatus | |
| JPS63187177A (en) | Assisting apparatus on nighttime navigation | |
| JP3519296B2 (en) | Automatic measurement method and automatic measurement device for thermal image | |
| US20250336173A1 (en) | Method for recording an overall image of the surroundings of a watercraft, device arrangement and camera | |
| JP2685407B2 (en) | Method and apparatus for measuring shape of shield segment | |
| JPH05231868A (en) | Surveying method | |
| JP7727474B2 (en) | monitoring device | |
| JP3409455B2 (en) | Infrared imaging device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |