WO2008103697A2 - Système d'imagerie marine - Google Patents

Système d'imagerie marine Download PDF

Info

Publication number
WO2008103697A2
WO2008103697A2 PCT/US2008/054366 US2008054366W WO2008103697A2 WO 2008103697 A2 WO2008103697 A2 WO 2008103697A2 US 2008054366 W US2008054366 W US 2008054366W WO 2008103697 A2 WO2008103697 A2 WO 2008103697A2
Authority
WO
WIPO (PCT)
Prior art keywords
mirror
axis
light
imaging system
camera
Prior art date
Application number
PCT/US2008/054366
Other languages
English (en)
Other versions
WO2008103697B1 (fr
WO2008103697A3 (fr
Inventor
Robert K. Cowen
Cedric M. Guigand
Original Assignee
University Of Miami
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 University Of Miami filed Critical University Of Miami
Publication of WO2008103697A2 publication Critical patent/WO2008103697A2/fr
Publication of WO2008103697A3 publication Critical patent/WO2008103697A3/fr
Publication of WO2008103697B1 publication Critical patent/WO2008103697B1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B45/00—Arrangements or adaptations of signalling or lighting devices
    • B63B45/02—Arrangements or adaptations of signalling or lighting devices the devices being intended to illuminate the way ahead or other areas of environments

Definitions

  • the present invention relates to a method and system for oceanographic research imaging, and in particular, to a method and system for imaging small marine organisms in situ.
  • Zooplankton can typically be classified in two sub-categories of size: microzooplankton (typically 50 to 250 micrometers, equivalent spherical diameter (“esd”)); and macrozooplankton (typically 250 micrometers to 20 mm, esd).
  • esd equivalent spherical diameter
  • esd macrozooplankton
  • Fish can also be sub-categorized by their size and/or stage of development: fish eggs (typically 1 mm in diameter); fish larvae (typically 1 to 3 cm in length); and juvenile and adult fish of sizes larger than that of their larval stage.
  • Phytoplankton and zooplankton are often measured in the oceans and subsequently studied for their interrelationships and for their effect on fisheries. Information is often collected and later provided regarding the abundance and vertical distributions of phytoplankton, zooplankton, and fish in continental shelf waters, deep oceans, as well as inland waters. Acquiring such information or data accurately, continuously and with wide spatial coverage provides a significant sampling problem, especially given the limited ship-time that may be available.
  • the light attenuance meter is less accurate in measuring phytoplankton biomass than the fluorometer but does provide a reasonable profile of "relative biomass" when calibrated against a fluorometer at several points in sea water.
  • the deployment of zooplankton sampler nets from ships is generally cumbersome, time consuming and provides limited spatial coverage.
  • the nets often clog with phytoplankton material and must be recovered after short tows, e.g., having a duration of approximately 10 minutes or less.
  • vertical information with respect to the zooplankton in the water column is generally lost, since the collected samples are integrated in the net.
  • a marine imaging system able to provide high-resolution imaging of small particles or organisms, such as phytoplankton, zooplankton, and fish, in a parcel of water having sufficient volume to quantify even relatively rare organisms, such as icthyoplankton, for the assessment of vertical and horizontal distribution of plankton and size classes. It is further desirable to provide a marine imaging system that does not overly disturb or alter the monitored environment with excessive illumination and/or the introduction of undesired amounts of turbulence.
  • the present invention advantageously provides a marine imaging system, including a light source emitting light along a first axis; a first mirror receiving light from the light source, the first mirror reflecting at least a portion the light emitted from the light source along a second axis; a second mirror receiving light reflected by the first mirror, the second mirror reflecting at least a portion of the received light along a third axis; and a camera receiving at least a portion of the light reflected by the second mirror.
  • the light source may include a light emitting diode having an emitted wavelength between approximately 400 and approximately 500 nm.
  • the system may also include a first lens positioned between the light source and the first mirror, and a second lens positioned between the second mirror and the camera.
  • An optical condenser may be positioned between the light source and the first mirror.
  • the second axis may be substantially perpendicular to the first axis
  • the third axis may substantially perpendicular to the second axis.
  • the light source, first mirror, second mirror, and camera may be disposed within a submersible housing of a watercraft, where the submersible housing includes a first pod and a second pod, the first pod housing the light source and first mirror, and the second pod housing the second mirror and the camera, and where the first and second pods are offset to allow water to pass therebetween.
  • the present invention further provides a method of imaging marine organisms, including emitting light along a first axis; reflecting the light along a second axis substantially perpendicular to the first axis, wherein the reflected light along the second axis passes through a volume of water; reflecting a portion of the light passing through the volume of water along a third axis substantially perpendicular to the second axis; and capturing an image from the light directed along the third axis.
  • the method may further include moving the light source through a body of water.
  • FIG. 1 is an illustration of an embodiment of a marine imaging system constructed in accordance with the principles of the present invention.
  • FIG. 2 is an additional illustration of an embodiment of a marine imaging system constructed in accordance with the principles of the present invention. DETAILED DESCRIPTION OF THE INVENTION
  • the present invention provides an oceanographic marine imaging system capable of imaging small particles or planktonic organisms (i.e., sizes less than about lmm to 10+ cm) at a very high resolution in a parcel of water that is of sufficient volume to quantify the particles or organisms therein.
  • the system of the present invention may be used to determine the vertical and horizontal distribution of plankton size classes to a fine detail or resolution that was previously difficult if not impossible to achieve.
  • the system of the present invention further allows for rapid sampling as compared to traditional plankton nets or existing imaging systems, thereby reducing the time required to survey certain locations of the ocean and/or to do so in grater detail.
  • the imaging system 10 generally includes an optical assembly 12 including a camera 14 fitted into or otherwise mounted upon a water- borne vehicle or marine craft, as discussed in more detail below.
  • the optical assembly may include one or more light sources, lenses, mirrors, and/or other optical components for manipulating a light path 15 and the properties thereof to facilitate video capture of an illuminated specimen or water volume.
  • the optical assembly of the imaging system 10 may include a combination of a light emitting diode (“LED”) light source and a plurality of plano-convex lenses to create a collimated light field, where the collimated light field back-lights a parcel of a water column for image capturing by a high-resolution line scan camera.
  • a lighting source and technique involving shadow illumination may be employed. Focused shadowgraph techniques, as known in the art, allow for a long depth of field not achievable with other lighting techniques, such as off-axis illumination or simple backlighting.
  • Use of a shadowgraph lighting scheme provides enhanced contoured as well as contrasted images of small, semi-transparent organisms such as zooplankton.
  • a small, compact, vibration resistant light source such as an LED can be used without the need for overpowered or strobing operation, which results in a simplified design and an increasingly robust system 10.
  • the optical assembly 12 of the marine imaging system 10 of the present invention may include a light source 16, such as an LED, an optical condenser 18 to manage the quality and intensity of the light, a pinhole 20, and a first lens 22.
  • a light source 16 such as an LED
  • an optical condenser 18 to manage the quality and intensity of the light
  • a pinhole 20 to manage the quality and intensity of the light
  • a first lens 22 to manage the quality and intensity of the light
  • a first lens 22 a first lens 22.
  • the light source 16 may include an LED emitting light along a first axis 24 in a substantially violet/blue wavelength (i.e. 400 to 500 nm), which produces a suitable amount of light for observing fish larvae in a relatively undisturbed environment.
  • a substantially violet/blue wavelength i.e. 400 to 500 nm
  • the LED creates a point source of light (4 mm diameter, for instance) which is then refocused on the pinhole 20, which may measure approximately lmm for example, using the condenser lens assembly 18 (which may include lenses of 27 mm diameter and 6.9 mm focal length, for example).
  • the light emerging from the pinhole 20 spreads to meet the first lens 22, which may be a 150 mm diameter plano-convex lens, for example.
  • the light passing through the lens 22 may then be reflected by a first mirror 26 along a second axis 28.
  • the first mirror 26 may be oriented at an approximately 45 degree angle to the first axis 24 of the light path to direct the light emitted through the first lens 22 in a substantially perpendicular direction, that is to say, the second axis 28 may be substantially perpendicular to the first axis 24.
  • the reflected light is then directed towards a second mirror 30, which may also be oriented at an angle of approximately 45 degree angle to direct the light along a third axis 32 substantially perpendicular to the second axis 28 (and parallel to the first axis 24).
  • This plano-convex collimating (150 mm diameter, 586 mm focal length) lens and mirror arrangement creates a beam of light through a volume of sampled water 34 present or passing between the first and second mirrors, as discussed in more detail below.
  • the beam of light then passes through a second collimating lens 36 and is refocused before it impinges on the camera 14.
  • the camera 14 may include a line-scan camera, which may be fitted with an 85 mm focal length imaging lens, for example. Such cameras function differently from traditional area-scan charge coupled device (“CCD") cameras.
  • the line-scan camera creates a picture by adding subsequent line fractions of images as the object being imaged moves perpendicular to its axis. This creates a continuous image, which contrasts with sequential flashed photography or video images in the sense that flash/video are successive images that may overlap each other or create gaps if the object being imaged is not moving in synchronization with a camera's frame rate. Hi- speed scanning rates of the line-scan camera also allow for high resolution images.
  • a camera may be used having a vertical resolution of 2048 pixels, with a line scanning rate of 36,000 Hz.
  • a continuous visual field of approximately 14 cm vertically and with a 20 cm depth of field may be obtained.
  • the volume of water imaged every second would be ca. 70 liters (14 cm X 20 cm X 250 cm) or -0.07 m3.
  • a typical 1 square meter plankton net filters ca.
  • the system 10 of the present invention using the exemplary camera described is capable of imaging close to 10% of the volume filtered by a net, which is greater than an order of magnitude improvement over existing imaging system 10s.
  • the resulting pixel resolution is approximately 68X68 microns per pixel. As a typical larval fish may be 2X6 mm, then over 2600 pixels would be resolving each larva, resulting in a very high resolution image.
  • the described optical assembly and arrangement of components provides and economical system 10 in terms of light intensity, as all of the light entering the sampled volume between the mirrors is directed towards the camera. This avoids the use of bright light sources that could deter organisms away from the imaging area, and also results in smaller power requirements for operation of the selected light source.
  • the described optical scheme makes the system 10 telecentric, meaning that magnification is independent of distance from the camera 14, thereby providing the opportunity to accurately measure the size of zooplankters within the imaged volume or sample.
  • the shadowgraphy technique allows for a large depth of field (approximately 20-40 cm, for example), which greatly enhances the volume of water being imaged as compared to macro and micro photography.
  • the optical assembly 12 may be affixed, mounted, positioned or otherwise coupled to a marine craft or water-borne vehicle or platform 38.
  • the optical assembly 12 may be integrated into a submersible housing 40 to perform the subsequent marine imaging.
  • the submersible housing may generally include two streamlined pods, where the light source 16, first lens 22, and first mirror 26 are positioned in a first pod 42, and the second mirror 30, second lens 36, and camera 14 are positioned in a second pod 44.
  • the first and second pods may each include a transparent window or port 46, 46'opposite the first and second mirrors, respectively such that light is transmitted from the first pod 42, as directed by the first mirror 26, to the second pod 44 for direction from the second mirror 30 to the camera 14.
  • the ports or windows may include, for example, a water-tight acrylic window.
  • the first and second pods may be sufficiently offset to allow water to pass in between the two pods (and in particular, past the two window ports and/or the first and second mirrors) for imaging, and may include a streamlined or similarly hydrodynamic body or component to reduce turbulence around the lighted sample when in use.
  • each pod may include a conical-shaped front end to facilitate movement through a water column, and a stabilizing keel and/or wing 48 may be also be coupled to the craft to provide enhanced movement control or stability of the device.
  • the imaged parcel of water passes between the forward portions of the two streamlined pods and thereby remains unaffected by turbulence.
  • a very high-resolution image of zooplankton in their natural position and orientation may be collected.
  • the optical assembly may be towed behind a boat or similar water craft, it is also contemplated that the marine craft housing the optical assembly may further include a propulsion mechanism and related controls or operative components, similar to that found in Autonomous Underwater Vehicles ("AUVs”), or small Remotely Operated Vehicles (“ROVs”), to allow the system 10 of the present invention to be operated independently of a boat or other observation platform.
  • UAVs Autonomous Underwater Vehicles
  • ROVs Small Remotely Operated Vehicles
  • the marine craft/platform 38 may also include one or more sensors 50 that measure, collect, or otherwise analyze various characteristics of the operating environment surrounding the craft and/or the optical assembly. For example, temperature, flow rate, salinity, pressure and/or light sensors may be included on the body of the craft and/or the first and second pods for the collection of data ancillary to the image recording. Moreover, the craft may include depth and/or pitch sensors 52 to aid in orienting the craft, and thus the optical assembly, into a desired position with respect to the water flow. Of course, a power supply 54 (such as batteries or the like) may also be included for the operation of the components described herein.
  • a power supply 54 such as batteries or the like
  • the marine imaging system 10 may also include a data collection and/or transfer module (not shown) for storing and/or relaying the collected images and information to an observation platform.
  • the data collection module may include one or more electronic storage elements where the images and information obtained from the cameras and one or more sensors is stored for later retrieval.
  • a high throughput disc array (having approximately 160 GB storage space, for example) may include a plurality of hard drives controlled by a high performance computer with continuous real-time recording at 140MB/second. Should it be desirable to immediately port the recorded data to an observation platform or ship, a high through-put communication protocol may be employed to establish communication between the optical assembly of the marine craft and a ship.
  • a fiber optic coupling may directly link the camera to a fiber optic extender communicating data to a shipboard computer via a copper/ fiber optic oceanographic cable.
  • a fiber optic coupling may directly link the camera to a fiber optic extender communicating data to a shipboard computer via a copper/ fiber optic oceanographic cable.
  • additional and/or alternative communication methodologies and protocols may be equally usable with the system 10 of the present invention.
  • the imaging system 10 may be used for observing, imaging or otherwise collecting information regarding other suspended particles or elements within a particular body of water.
  • the bilge contents of large oceanic vessels may be analyzed for the presence of exotic or otherwise invasive organisms prior to discharging bilge tanks into coastal ports.
  • the imaging system 10 of the present invention may be anchored or otherwise affixed to a stationary structure for the recording and analysis of the flux or passage of particles or organisms across a particular location for an extended duration of time.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Studio Devices (AREA)
  • Cameras In General (AREA)

Abstract

L'invention concerne un système d'imagerie marine qui comprend un logement submersible comprenant une première nacelle et une seconde nacelle, les première et seconde nacelles étant décalées pour permettre à l'eau de passer au travers ; une diode électroluminescente disposée dans la première nacelle, la diode émettant de la lumière le long d'un premier axe ; un premier miroir disposé dans la première nacelle, le premier miroir recevant de la lumière provenant de la diode et réfléchissant au moins une partie de la lumière le long d'un deuxième axe ; un second miroir disposé dans la seconde nacelle, le second miroir recevant de la lumière réfléchie par le premier miroir et réfléchissant au moins une partie de la lumière reçue le long d'un troisième axe ; et une caméra disposée dans la seconde nacelle, la caméra recevant au moins une partie de la lumière réfléchie par le second miroir.
PCT/US2008/054366 2007-02-20 2008-02-20 Système d'imagerie marine WO2008103697A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US90207807P 2007-02-20 2007-02-20
US60/902,078 2007-02-20

Publications (3)

Publication Number Publication Date
WO2008103697A2 true WO2008103697A2 (fr) 2008-08-28
WO2008103697A3 WO2008103697A3 (fr) 2008-11-13
WO2008103697B1 WO2008103697B1 (fr) 2008-12-24

Family

ID=39710713

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2008/054366 WO2008103697A2 (fr) 2007-02-20 2008-02-20 Système d'imagerie marine

Country Status (1)

Country Link
WO (1) WO2008103697A2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108398844A (zh) * 2018-04-26 2018-08-14 浙江大学 可拍摄浑浊水体中浮游生物剪影的水下背影成像系统
CN112668681A (zh) * 2020-12-24 2021-04-16 杭州海康机器人技术有限公司 一种包裹信息的确定方法、系统、装置及相机
DE102021109153A1 (de) 2021-04-13 2022-10-13 Geomar Helmholtz-Zentrum Für Ozeanforschung Kiel Verfahren zur verbesserten optischen Auflösung in großen Messvolumina bei der telezentrischen Shadowgraphie und Vorrichtung zur Durchführung des Verfahrens
CN115184276A (zh) * 2022-08-09 2022-10-14 中国科学院海洋研究所 拖曳式浮游生物偏振成像记录仪

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040109586A1 (en) * 2002-12-04 2004-06-10 Scott Samson Shadowed image particle profiling and evaluation recorder
US7019849B2 (en) * 2003-03-18 2006-03-28 Jasco Corporation Depth measuring apparatus
US7134754B2 (en) * 2001-04-09 2006-11-14 Patrick Kerr Retinal function camera

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7134754B2 (en) * 2001-04-09 2006-11-14 Patrick Kerr Retinal function camera
US20040109586A1 (en) * 2002-12-04 2004-06-10 Scott Samson Shadowed image particle profiling and evaluation recorder
US7019849B2 (en) * 2003-03-18 2006-03-28 Jasco Corporation Depth measuring apparatus

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108398844A (zh) * 2018-04-26 2018-08-14 浙江大学 可拍摄浑浊水体中浮游生物剪影的水下背影成像系统
CN112668681A (zh) * 2020-12-24 2021-04-16 杭州海康机器人技术有限公司 一种包裹信息的确定方法、系统、装置及相机
CN112668681B (zh) * 2020-12-24 2022-07-01 杭州海康机器人技术有限公司 一种包裹信息的确定方法、系统、装置及相机
DE102021109153A1 (de) 2021-04-13 2022-10-13 Geomar Helmholtz-Zentrum Für Ozeanforschung Kiel Verfahren zur verbesserten optischen Auflösung in großen Messvolumina bei der telezentrischen Shadowgraphie und Vorrichtung zur Durchführung des Verfahrens
DE102021109153B4 (de) 2021-04-13 2022-12-22 Geomar Helmholtz-Zentrum Für Ozeanforschung Kiel Verfahren zur verbesserten optischen Auflösung in großen Messvolumina bei der telezentrischen Shadowgraphie und Vorrichtung zur Durchführung des Verfahrens
CN115184276A (zh) * 2022-08-09 2022-10-14 中国科学院海洋研究所 拖曳式浮游生物偏振成像记录仪
CN115184276B (zh) * 2022-08-09 2023-09-26 中国科学院海洋研究所 拖曳式浮游生物偏振成像记录仪

Also Published As

Publication number Publication date
WO2008103697B1 (fr) 2008-12-24
WO2008103697A3 (fr) 2008-11-13

Similar Documents

Publication Publication Date Title
Cowen et al. In situ ichthyoplankton imaging system (ISIIS): system design and preliminary results
US10488344B2 (en) System for rapid assessment of water quality and harmful algal bloom toxins
Davis et al. A three‐axis fast‐tow digital Video Plankton Recorder for rapid surveys of plankton taxa and hydrography
Samson et al. A system for high-resolution zooplankton imaging
US20170293217A1 (en) Continuous particle imaging and classification system
Davis et al. The video plankton recorder (VPR): design and initial results
Jaffe et al. Underwater optical imaging: status and prospects
Talapatra et al. Characterization of biophysical interactions in the water column using in situ digital holography
Kocak et al. The current art of underwater imaging–with a glimpse of the past and vision of the future
Sun et al. In situ underwater electronic holographic camera for studies of plankton
CN109981929A (zh) 水下浮游生物光学成像装置及方法
CN107271371A (zh) 一种浮游生物偏振成像仪
WO2008103697A2 (fr) Système d'imagerie marine
Rooper et al. Estimating species and size composition of rockfishes to verify targets in acoustic surveys of untrawlable areas
Pfitsch et al. Development of a free-drifting submersible digital holographic imaging system
CN108267427B (zh) 海底底质光谱测量方法和设备以及终端
Benfield et al. Estimating the in-situ orientation of Calanus finmarchicus on Georges Bank using the Video Plankton Recorder
CN101566577A (zh) 中小型海洋浮游动物景深成像监测装置
Clement et al. Fishery applications of optical technologies
RU148827U1 (ru) Подводный видеорегистратор планктона
Dalgleish et al. Extended range distributed laser serial imaging in turbid estuarine and coastal conditions
Dickman et al. Three‐dimensional odorant concentration measurements around actively tracking blue crabs
Lindsay et al. The uROV PICASSO, the Visual Plankton Recorder, and other attempts to image plankton
Christiansen Deep‐Sea Zooplankton Sampling
Harsdorf et al. Design of an ROV-based lidar for seafloor monitoring

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08730213

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08730213

Country of ref document: EP

Kind code of ref document: A2