Unit II- Ocean Technology- Table of Contents

Transcription

1 Unit II- Ocean Technology- Table of Contents This material is background information for teachers. This should be read and discussed before presentation. Student Information Sheets: This is background material for students. They should be copied and given to students before the video presentation. Activities should be done as a follow-up after the program. Questions should be discussed after the show. Table of Contents ` 1 Acknowledgements 2 Science Standards 3 Introduction: Engineering the Future of Marine Sensing 4 Lesson 1 Oceanographic Research- Gathering Data in the Field 5 Ocean-going Research Vessels 5 Harsh Environments 5 Underwater Robots: Autonomous Underwater Vehicles (AUVs) 6 Advantages 6 What Do Typical AUVs Look Like? 6 How Do They Work? 7 How are AUVs Used or What Can They Do? 7 Student Information Sheet ` 9 Lesson 2 Oceanographic Instruments 11 Shadowed Image Particle Profiling Evaluation Recorder, SIPPER 11 Real-time Ocean Bottom Topography System, ROBOT 12 Side Scan Sonar 13 Spectrophotometric Elemental Analysis System, SEAS 15 Underwater Mass Spectrometer 17 Microelectromechanical Systems, MEMS Devices 18 Student Information Sheet 19 Activity: Research and Learn 21 Vocabulary 22 Internet Resources 23 References 23 1

2 Unit II Center for Ocean Technology The staff at Project Oceanography would like to thank the following people for their assistance in preparing this packet: Executive Producer: Paula Coble, Ph.D. Graphics: Chad Edmisten Lori Huthmacher Writers: Lori Huthmacher Carol Steele Edited by: Paula Coble, Ph.D. Juli Rasure Packet Distribution: Tracy Christner Source Information Sites: NASA and 2

3 SCIENCE Strand the nature of matter energy the nature of science MATHEMATICS Strand measurement data analysis and probability LANGUAGE ARTS Strands writing listening, viewing, and speaking 3

4 COT Introduction: Engineering the Future of Marine Sensing The Center for Ocean Technology (COT) exists to provide engineering support and expertise to the scientists in the University of South Florida's (USF) Marine Science Department. The Center's professional staff has engineering expertise in electronic, optical, chemical, mechanical and software engineering. The staff also has a proven capability in the full spectrum of product development, from design to fabrication. When scientists need a special ocean research instrument, they can have COT help design and build it. The Center for Ocean Technology is an intellectual and technical resource that allows USF's marine scientists to conquer the difficult engineering problems inherent in their cutting edge oceanographic work. This collaboration has focused on developing an array of marine sensors integrated with autonomous underwater vehicles (AUVs). The resultant technology, with its commercial and military applications, has contributed significantly to the collection of data in an aqueous environment. "What we're trying to do here is build a capability we've never had before and offer it to the entire scientific community," says Dr. Thomas L. Hopkins, the Center's Director and a professor of biological oceanography. 4

5 Lesson I. Oceanographic Research, Gathering Data in the Field Ocean-going research vessels How do we get information about the things we want to study in the ocean? One of the ways that we can get information is by actually going out to sea on ships. There are several different sizes of ships used for oceanographic research. The Florida Institute of Oceanography, located on the USF campus, primarily uses a 71' vessel called the RV Bellows. This is considered one of the smaller ships. An example of a medium sized ship would be the 274' RV Atlantis built in RV Atlantis is owned and operated by The Woods Hole Oceanographic Institute, connected with the Massachusetts Institute of Technology. Texas A&M University uses a 470' ship called the RV Sedco/BP for their research in the Gulf of Mexico. Obviously, the larger the vessel, the more equipment and scientists it can hold and the longer it can stay out at sea gathering research. Harsh Environments Scientists do not always encounter clear conditions when "at sea". Often they endure harsh conditions, so it is important that the equipment be sturdy. Ships and instruments must be carefully maintained while they are being utilized for research. Sea-water is a corrosive medium and can quickly destroy valuable equipment. Some conditions that may interfere with research include: surface weather such as storms, working in very cold temperatures at high latitudes, significantly increased pressure on the instruments as they are lowered deeper and deeper into the ocean and motion sickness. 5

6 Underwater robots: Autonomous Underwater Vehicles (AUVs) Advantages The autonomous underwater vehicles (AUVs) developed at USF are smaller and easier to operate than research vessels. They are relatively inexpensive to build and maintain: the average cost to build each unit is $70,000. The instruments that go on the AUV can cost from $5,000 to $100,000 each. The operation cost of an AUV at sea is approximately $1000 per day. AUVs are extremely versatile because they are scalable, upgradable and reconfigurable, which means researchers can use the same basic design and modify the components. The network used to communicate between the components on the AUV is an offthe-shelf item that is relatively inexpensive. USF s AUV is shaped like a torpedo and has been nicknamed the "yellow submarine. It is 7-10 feet long, 21 inches in diameter, and weighs between lbs. AUVs are streamlined with a hydrodynamically designed hull to minimize drag. Compare USF s What do typical AUVs look like? yellow submarine s measurements to the British Autosub AUV, which is 23 feet long, 3 feet in diameter and weighs 3300 lbs! Or the Woods Hole REMUS AUV that is 52 inches long, 7.5 inches in diameter and weighs 66 lbs! 6

7 Ocean Explorer (modular design!!) How do they work? The AUV tail hull section is the propulsion unit, while the forward section is designed for missionspecific research instruments. The cavity of the AUV is flooded with water to help equalize the pressure with the water that surrounds it. All of the instruments inside are sealed in specially designed pressure vessels. Autonomous underwater vehicles have a computer on board that works with intelligent distributed control (IDC) technology to steer the AUV and collect oceanographic research data. IDC technology has become common in the AUV industry; however, its applications are by no means limited to the marine environment. In general, IDC allows several instruments or control elements to be connected together in a simple, yet versatile network. Each connect element (called a node) can communicate over the network, and each can contain some intelligence (software) that allows it to operate independently should the network fail. How are AUVs used or what can they do? USF s AUV can dive up to 600 meters, but works best at 450 meters. It has a range of 20 nautical miles and an 7

8 endurance of 5-8 hours. It moves at a speed of 2-5 knots. It is battery powered, with a battery capacity of five working hours. It takes five hours for the battery to recharge. AUVs are neutrally buoyant so they don't sink! Primarily AUVs carry sensors that are designed for very specific tasks. They can: look at small particles in the ocean look at temperature, salinity and other physical parameters associated with the water detect chemical pollutants study behavior of ocean currents detect or find weapons in water. The weapons could be small (guns and knives) or large (military weapons) 8

9 Student Information Sheet Lesson 1 Ocean-going research vessels How do we get information about the things that we want to study in the ocean? One of the ways we can get information is by actually going out to sea on ships. The larger the vessel, the more equipment and scientists it can hold and the longer it can stay out at sea gathering research. Harsh environments Scientists do not always encounter clear conditions when "at sea". Often they endure harsh conditions, so it is important that the equipment be sturdy. Ships and instruments must be carefully maintained while they are being utilized for their research capacities. Sea-water is a corrosive medium and can quickly destroy valuable equipment. Some conditions which may interfere with research include: surface weather such as storms, pressure systems and motion sickness. Underwater robots: Autonomous Underwater Vehicles (AUVs) Advantages The autonomous underwater vehicles (AUVs) developed at USF are smaller and easier to operate than research vessels. They are relatively inexpensive to build and maintain: the average cost to build each unit is $70,000. The instruments that go on the AUV can cost from $5,000 to $100,000 each. The operation cost of an AUV at sea is approximately $1000 per day. AUVs are extremely versatile because they are scalable, upgradable and reconfigurable, which means researchers can use the same basic design and modify the components. The network used to communicate between the components on the AUV is an off-the-shelf item that is relatively inexpensive. 9

10 How do they work? Autonomous underwater vehicles function with an internal computer. The tail hull section contains most of the dedicated components, while the forward section is free for mission-specific components. Intelligent distributed control technology is proven beneficial for development of instrumentation systems utilized in oceanographic research. The versatility of the technology has allowed quick implementation of solutions for control and data collection, thus allowing more time to be spent on development of measurement systems. The technology, born of needs in industry, is become in more prevalent and is by no means limited to marine applications. How are AUVs used or what can they do? Primarily AUVs carry sensors that are designed for very specific tasks. They can: look at small particles in the ocean. look at temperature, salinity and other physical parameters associated with the water detect chemical pollutants. detect or find weapons. study behavior of ocean currents. 10

11 Lesson II. Oceanographic Instruments Shadowed Image Particle Profiling Evaluation Recorder, SIPPER The Shadowed Image Particle Profiling System (SIPPER) is an optical imaging system designed to produce high resolution images of very small sea life. SIPPER s sampling tube has a cross section of 100mm by 100mm, and it has been optimized to yield very good images of very small specimens within the entire sampling tube. Below is a schematic of the SIPPER instrument. A laser with line generator optics creates a fan beam of light, which is brought back together by a first lens. The resulting beam is 100mm wide by 1mm high and passes through a clear opening in the sides of a square sampling tube. The imaging lens produces an unchanged and demagnified image of the particles onto a line scan camera. The digital output from the camera is sent to an image processing board (not shown in the schematic), which acquires the data and displays and saves the sequential lines on a computer. Shown on page 12 is a picture of a light bulb filament taken by the SIPPER. 11

12 Image of a 1.5mm diameter light bulb filament and a 250 micron optical fiber at the center of the sampling tube, moving at 0.25 m/sec through the light sheet. The camera scan rate is 6000 lines/sec. The figure shows a 3.62 mm portion of the 100 mm sample cross section. Real-time Ocean Bottom Topography System, ROBOT Range scanning, illustrated in the figures below, can provide realtime range information along with shape, orientation, texture, and volume of a target. Laser light, generated in a fan pattern as illustrated in the first figure, illuminates the bottom surface as the host platform moves across the sea bed. A high speed (700fps) 256 by 256 pixel camera views the illuminated scene, captures and analyzes data in real time, and transmits it to a display computer. AUVs typically have sophisticated control systems that allow for optimization of mission parameters. Parameters such as uniform mean altitude, constant velocity (either with respect to ground or water) and accurate positioning make AUVs ideal as a platform to carry the Real-time Ocean Bottom Topography (or ROBOT) system. 12

13 The figure above shows range scanning with a low power laser and a high speed CCD camera. Data are stored in line scan form, 256 bytes at a time in the host computer. Initial processing of "brightest pixel" information, using a threshold process, as well as the option of more sophisticated processing (successive approximation) is performed in the camera itself. The figure below shows a scanned image of a calibration "stair step" platform examined at a speed of 1 m/sec in air. Once only of interest to the military, side scan sonar offers a unique ability to locate objects underwater with near photographic Side Scan Sonar quality. Sonar uses sound waves instead of light, and can see much farther in water. Until the advent of imaging type sonars, 13

14 objects lost overboard and even ship wrecks virtually disappeared until located by underwater divers, sometimes many years later. Imaging sonar has opened the door to an entirely new capability for ocean scientists, enforcement law enforcement personnel (who use it for evidence retrieval and recovery of drowned victims), treasure hunters and amateur divers (who can more quickly locate shipwrecks and debris from wrecks). The side scan sonar makes all underwater searches more efficient. The photo below shows the side scan sonar as it is encapsulated in the torpedoshaped towfish. Also included in the picture are the additional parts to the side scan sonar system: the computer (in the yellow case), cable and sun hood (to better focus on the computerized pictures). The side scan sonar plots the ship s position, the position of the object, and tracks swath coverage. The operator of the side scan sonar is able to see the big picture and is also able to zoom in on objects of interest. Below is a side scan sonar picture of a body at the bottom of a lake. 14

15 Spectrophotometric Elemental Analysis System, SEAS The purpose of this instrument is to allow in situ measurement, with greatly extended detection limits, of essential oceanic trace metals and nutrient ions. The instrument as developed contains a 4.5 meter optical path length. Using the long optical path length and colorimetric procedures for seawater analysis developed by many investigators This spectrophotometric approach is versatile in that multichannel spectrophotometric systems are capable of performing analyses for iron, manganese, copper, phosphate, ammonia, nitrate, nitrite, ph, alkalinity and The instrument s long optical path length is obtained with a liquid core 15 over more than fifty years, the chemistry of the upper ocean can be studied in a manner heretofore impossible. With a single type of measurement (long path length spectroscopy) simultaneous in situ analysis of a variety of solutes can be obtained rapidly and without preconcentration. others. This capability is important in learning more about the chemistry of the ocean. Closer to home, this instrument could be used in all types of water control systems to determine whether or not the water is fit to drink. waveguide (LCW). The liquid medium inside the waveguide has

16 a refractive index that is greater than the surrounding medium; therefore, light is constrained within the waveguide. The outstanding features of this approach to measuring oceanic trace metals and nutrient ions is that because it uses a very small sample volume, the size of the total instrument is also small. The typical sample volume needed for a five-meter path length is on the order of 1cm 3. The LCW itself can be coiled into a volume on the order of 25 cm 3 or smaller. Shown below is a schematic of the LCW. The water enters the water pump and is mixed with a dye that will determine the presence or absence of the chemical of interest. The mixed fluid is sent through the LCW, and is ejected. 16

17 The light from the LCW is measured and interpreted by the spectrometer, which determines the amount and intensity of the chemical of interest. Numerous scientific groups have made progress in identifying chemicals, measuring their concentrations and understanding their interactions within the water column. What is missing from this work is a comprehensive sensor that would provide a complete picture. For this reason, the Center for Ocean Technology is working to develop an in situ mass spectrometer that can be deployed on an AUV. The mass Underwater Mass Spectrometer spectrometer will fill the need for a comprehensive sensor because of its versatility and power. Mass spectrometry provides high resolution molecular fingerprinting; that is; it yields unambiguous information about molecular structure and identity. In addition, mass spectrometry has the potential to detect all elements in the periodic table. The following schematic depicts how mass spectrometers do their work. Microelectromechanical Systems, MEMS Devices The miniaturization revolution in instrumentation has emerged as the driving force in the development of electronic, 17

18 biomedical, analytical and electromechanical systems. The present trend indicates that microsystems technology will influence a vast number of products and services over a wide range of industries around the world. Current emphasis on microinstrumentation development focuses primarily on biomedical, chemical and automotive applications. To date oceanographic microsystems have been neglected, yet they offer an opportunity to develop relevant sensor systems for coastal surveillance and defense, sea exploration, management of emerging economic zones (EEZs) worldwide and deployment of unattended ground sensors (UGS) for military surveillance, meteorology and global climate measurements. Microsystems technology, commonly called MEMS (microelectromechanical systems), is made up of miniature electrical and mechanical devices using structures about the width of a human hair. They are an offshoot of the technology associated with fabricating integrated silicon devices. This is a large field that incorporates all existing "micro structure" technologies, but is simply machinery at a smaller scale. Some everyday examples of microsystems are airbag sensors, blood pressure monitors, computer disk drives and ink-jet printer heads. The University of South Florida s Department of Marine Science is undertaking a project to develop marine sensors using MEMS technology. The approach capitalizes on industry development efforts that have created micro pumps, sophisticated optical devices, accelerometers, motors/geared devices and pressure transducers. The successful creation and implementation of such sensors will open the door to vast, practical and inexpensive networks for monitoring and studying the world s aquatic environments. Student Information Sheet Lesson 2 Oceanographic Instruments 18

19 The Shadowed Image Particle Profiling System (SIPPER) is an optical imaging system designed to produce high resolution images of very small sea life. Real-time Ocean Bottom Topography System, ROBOT. Range scanning, can provide real-time range information along with shape, orientation, texture, and volume of a target. Side Scan Sonar. Once only of interest to the military, side scan sonar offers a unique ability to locate objects underwater with near photographic quality. Sonar uses sound waves instead of light and can see much farther in water. Spectrophotometric Elemental Analysis System, SEA. The purpose of this instrument is to allow in situ measurement, with greatly extended detection limits, of essential oceanic trace metals and nutrient ions. This spectrophotometric approach is versatile in that multichannel spectrophotometric systems are capable of performing analyses for iron, manganese, copper, phosphate, ammonia, nitrate, nitrite, ph, alkalinity and others. This capability is important in learning more about the chemistry of the ocean. Closer to home, this instrument could be used in all types of water control systems to determine whether or not the water is fit to drink. Underwater Mass Spectrometer. Numerous scientific groups have made progress in identifying chemicals, measuring their concentrations and understanding their interactions within the water column. Microelectromechanical Systems, MEMS Devices. The miniaturization revolution in instrumentation has emerged as the driving force in the development of electronic, biomedical, analytical and electromechanical systems. The present trend indicates that microsystems technology will influence a vast number of products and services over a wide range of industries around the world. Current emphasis on microinstrumentation 19

20 development focuses primarily on biomedical, chemical and automotive applications. To date oceanographic microsystems have been neglected, yet they offer an opportunity to develop relevant sensor systems for coastal surveillance and defense, sea exploration, management of emerging economic zones (EEZs) worldwide and deployment of unattended ground sensors (UGS) for military surveillance, meteorology and global climate measurements. 20

21 Activity I: Research and Learn Research the AUV (Autonomous Underwater Vehicle). Use various sources such as web sites, online encyclopedias, library books, magazines and journals. Write a two-page paper about how they work, when they were created, what they are used for and what instrumentation they carry. 21

22 Vocabulary A/D-Conversion- The conversion of continuous-type electrical signals varying in amplitude, frequency, or phase into proportional discrete digital signals. Absorptivity- Ratio of the absorbed to incident electromagnetic radiation on a surface. Acoustic Device- Active or passive sensor which detects acoustic waves rather than electromagnetic radiation. Acoustical Filter- Selective enhancement or reduction of the input acoustical waves. Acoustic Measurement- Quantification of acoustic waves. Acoustic Propagation- Transmission of sound through a medium (includes infrasound). Active remote sensing- Remote sensing methods that provide their own source of electromagnetic radiation to illuminate the terrain. Radar is one example. Advanced very high resolution radiometer (AVHRR)- Crosstrack multispectral scanner on a NOAA polar-orbiting satellite that acquires five spectral bands of data (0.55 to 12.50µm) with a ground resolution cell of 1.1 by 1.1 km. AVHRR- Advanced Very High Resolution Radiometer, a multispectral imaging system carried by the NOAA meteorological satellites. Band- A wavelength interval in the electromagnetic spectrum. For example, in Landsat images the bands designate specific wavelength intervals at which images are acquired. False Color Image- A color image where parts of the non-visible EM Spectrum are expressed as one or more of the red, green and blue components, so that the colors produced by the Earth's surface do not correspond to normal vision. NASA- National Aeronautical and Space Administration NOAA- National Oceanic and Atmospheric Administration NSSDC- National Space Science Data Center Ocean topography- The study of and graphical charting of the ocean to show the relative positions and elevations 22

23 Remote Sensing- Collection and interpretation of information about an object without being in physical contact with the object. Sea surface temperatures- These are measured by the Advanced Very High Resolution Radiometer (AVHRR) on NOAA polar orbiters. They determine temperatures by sensing infrared radiation coming from the sea surface. Current temperatures are updated for four-day periods. Submersible- A manned or unmanned underwater vehicle used for scientific research and military operations. Internet Resources for Teachers and Students rce_room.html daac.gsfc.nasa.gov/campaign_docs/ocdst/seawifs_raq.html daac.gsfc.nasa.gov/campaign_docs/ocdst/ob-news.html References Carol Steele- Center for Ocean Technology daac.gsfc.nasa.gov/campaign_docs/ocdst/seawifs_raq.html 23

24 David Fries, Chemical Sensor Engineer David Fries earned a BS in Chemistry at the University of Pittsburgh in 1985 and is currently pursuing his MS in Chemistry at the University of South Florida. In 14 years of professional experience, he has worked primarily on developing novel chemicals sensors that identify and characterize unknown organic materials. Many of these sensors utilize fiber optics and optical spectroscopy. Mr. Fries' current work focuses on the development of an underwater mass spectrometer and on needs-based chemical sensors. 24

25 Carol S. Steele, Administrative Manager Carol Steele has 20 years of administrative experience in program development, finance, technical writing and human resources development. She provides leadership in the Center's growing Government and industry relations, develops grant proposals, serves as technical writer and manages the Center's infrastructure. Ms. Steele has earned MA degrees in Geography/Urban Planning and in Counseling. She is currently pursuing a Ph.D. in Human and Organizational Development. 25