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We live in an ever-changing environment where there is a vital need for persistent monitoring of human activities; whether it is for security, safety, economic or environmental purposes. Our oceans are no exception and may even be the region of our globe that is most at risk. Unbeknownst to many, there is limited visibility and awareness of maritime activity beyond 40-50 nautical miles from our coastline. Shore-based technologies have limited range, space-based radar and other sensors have limited coverage, and marine patrol and synthetic aperture radar (SAR) assets are too costly to deploy over a wide area. Nevertheless, the ability to know the who, what and when of any transiting vessel near our coastline or in the open ocean is a critical piece of intelligence - whether it is to counter piracy, prevent illegal drug smuggling, reduce response time for search and rescue operations, combat illegal fishing, monitor marine protected areas (MPAs), etc.

Advances in the field of underwater optical imaging are reviewed for the years 2005 to present. A synopsis of research and technical innovations is presented, organized in much the same way as the previous report (Kocak and Caimi, 2005). Several recent applications of novel systems are shown as examples, and trends in emerging underwater imaging research and development are briefly summarized.

Satellite Automatic Identification System (AIS) technology has fundamentally changed the landscape for monitoring the maritime domain. Improving upon existing AIS technology already deployed aboard all large vessels and many smaller vessels around the globe, satellite AIS is truly revolutionary in providing a complete and global picture of the world's maritime shipping environment. To date, the exactView™ satellite constellation from exactEarth has shown that global coverage is possible with a variety of orbital regimes; but to provide a real-time view of the maritime domain, dramatic changes in a satellite AIS constellation are necessary. To address key changes in the AIS constellation architecture, exactEarth and HARRIS have partnered to provide real-time global maritime tracking and information solutions. This paper examines the elements and architectures required to bring about these changes t o provide a robust, real-time global view of the maritime domain in general, and AIS specifically. These include continuously improved onboard spectrum de-collision processing, a global and interconnected satellite constellation, and the ability to effectively adjust to and incorporate new and changing VHF maritime services including mandated frequency changes, new Application Specific Messages (ASM) and VHF digital exchange services and security protocols. In addition, this paper discusses performance metrics and a few key capabilities that will be greatly enhanced with this new real-time capability, which can be applied to a number of security, safety, economic and environmental use cases.

This report presents an overview and state of technology of the tools and techniques for underwater imaging, from ancient times through today, and suggests future prospects for advancement of the field. Text and a historical timeline start with direct observation techniques that commenced as early as 4500 B.C., when diving provided a means for food gathering and commerce to the invention of the first practical SCUBA in 1825. Present techniques are described in groups according to imaging methodology. The major research and technical innovations of the field are highlighted, focusing on the past five years. Trends in research and development are discussed as they relate to emerging underwater imaging techniques and technologies. These trends include advances in image sensor technology and a prototype underway by the Department of Homeland Security’s Project Hawkeye Intelligent Video Analysis, a maritime surveillance system that will monitor activities around and between ports.

This paper describes the outcomes of a TechSurge sponsored by the Marine Technology Society focused on ocean sensors. Specific goals of the meeting were (1) provide a forum for the exchange of information related to ocean sensors and their role in long-term, autonomous operation; (2) assess ocean observing systems and research goals and the specification of sensors to meet these goals; (3) identify gaps in available ocean sensors and RD and (4) produce a special edition of the MTS Journal that documents the state of ocean sensors and includes views toward future opportunities to make advances using emerging technologies (including from other disciplines) and collaborative efforts.

This chapter discusses photographic, digital, and video techniques commonly found in underwater imaging, as well as new and emerging trends. The chapter first reviews conventional imaging methods that utilize traditional camera hardware and digital signal processing and image processing techniques to produce enhanced linear perspective images. Next, the chapter reviews illumination techniques while taking into account special considerations for the underwater domain. Finally, the chapter closes with a discussion of emerging trends in the underwater imaging domain, including some unconventional imaging approaches and movement to a new computational paradigm.

This paper discusses the steps key to successful installation of complex seafloor communication, power and sensor networks. Emphasis on a systems engineering approach to design, development and deployment requiring the coordination of a diverse team of optical fiber specialists, marine cable engineers, technicians, deck hands, riggers, ROV operators, ship's crew and officers is essential to safely and efficiently install these systems at thousands of meters of ocean depth. This is illustrated through the detailed description of a system recently installed in the Eastern Mediterranean Sea. CSnet's Offshore Communication Backbone (OCB) will initially serve as the Tsunami Warning and Early Response system of Cyprus (TWERC). Nascent hydrocarbon exploration has also recently begun in this region. As this activity increases, leading to drilling and production, this OCB will similarly be expanded. In a phased approach, the TWERC will be extended to also service this offshore energy enterprise, supporting environmental and well monitoring sensors and providing two way broadband communications and power from seafloor to shore. The initial installation was completed in two preliminary phases. The first phase utilized two vessels (a cable ship and a DP II support ship), each equipped with remotely operated vehicles (ROVs), to lay a total of 255 km of cable, five seafloor nodes, an anchor interface and a seawater ground anode. Both multi-beam and visual (ROV) pre-deployment seafloor surveys of each node (junction box) site was performed. Installing each node, connectivity was maintained (power and communications) with the deployment vessel enabling its functionality to be continuously monitored while being lowered through the water column and after its touchdown on the seafloor. The second phase of this OCB installation deployed a moored buoy that provides both power and communication to the TWERC, in advance of any eventual shore-ended cable and power station and the attendant permitting required for such an installation. This phase required three surface vessels and an ROV to deploy the anchor, the buoy itself and nearly 2.4 km of riser cable with its associated buoyancy modules. Upon their installation, buoy and mooring were “plugged” into the anchor and anchor interface via ROV wet mate connectors (WMCs). Prior to final connection of the TWERC to the surface buoy, final system testing was performed through the riser cable aboard the deployment vessel. With successful operation established, the buoy and riser were connected to the seafloor network and complete end-to-end verification testing was performed over satellite to the Network Operations Command Center (NOCC) on shore. The system is now in operation. The successful installation of the TWERC OCB resulted from strictly adhering to a program management plan, installation storyboard, deployment plan, detailed event table, quality management plan, desktop study (DTS), subsea survey and permits, route position list, load method of procedure, contingency plans and schedule, among other exacting preparation. A step-by-step event table incorporating contingencies for unplanned events during deployment should result in significant cost and schedule savings in addition to the most important aspect, assurance of the safety of personnel and equipment. This was the case in the recent TWERC OCB installation, despite the complexities of coordinating the numerous surface vessels and subsea vehicles required to successfully install the system. This paper also outlines some of the best practices gathered from this and prior cabled seafloor installations, which may assist in future subsea installations. As Benjamin Franklin is purported to have said, “By failing to prepare, you are preparing to fail.”

Providing power to the seafloor to operate sensors and equipment reliably for long-term use requires a well thought out power return system as there are numerous obstacles in the harsh undersea environment. Cabled observatories typically employ commercial-off-the-shelf (COTS) telecommunications cables that contain optical fibers and a single power conductor, where the return path utilizes a seawater ground anode at the other end of the cable rather than a second (ground) conductor. Dissolution of the anode substrate, stray current effects, resistance, and hydrogen and chlorine concentrations must all be carefully considered in the design otherwise insurmountable problems can result and the life of the observatory can be shortened. For example, hydrogen can cause an increase in the attenuation of silica-based optical fibers and can degrade the performance of certain electronic components over time. These consequences result in costly cable and equipment replacement. This paper describes the design of an anode recently deployed on an undersea observatory in nearly 2400 meters of seawater, and includes discussions of the mechanical analysis, tipping moment calculations, skid design, rigging and redundancy. The life of the anode is expected to exceed 20 years, which makes this a practical solution for long-term offshore energy applications. In addition to the design, analysis is presented that assisted in optimal selection of the final design parameters. The minimum physical size of the electrodes, anode frame material, distance from the anode to the cable termination and physical positioning (i.e. buried or not buried in seabed sediments) of the anode and cathode are some examples of these parameters. This analysis considers potentials between the anode and cathodes, stray current effects from sea electrodes, chlorine concentrations in the vicinity of the anode, hydrogen concentration in the vicinity of the cathode, and the effects of hydrogen evolution at a platinized titanium cathode. Results from the design and analysis were taken into account in electrical models and simulations. This allowed careful examination of the transmission of DC power through the telecommunications cable and posing (and answering) “what if” questions that might arise to minimize potential problems during operation. Cabled observatories present the inherent challenge that complete system testing is normally impossible as key elements, such as the telecommunications cable, are only integrated at deployment. Even had the cable been available for integration testing, its reactive properties are different deployed than at a test facility. The potential cost implications of such an unexpected interaction post deployment could result in unrecoverable loss. Finally, techniques used to install and operate the anode on the ocean observatory are presented along with actual footage from the deployment. Current and voltage drop measurements taken during deployment were in good agreement with those predicted from our analysis and simulations, which help to validate this design and analysis process. Taking a thorough systems engineering approach from the start of this small but critical piece of the cabled observatory more than justifies the investment when the system performs and operates as expected.

This paper discusses the importance of taking a systems engineering approach when designing undersea networks, ocean observatories and offshore communications backbones. A design that utilizes modular components and systems, and places diligence in modeling and testing communications, power and data bandwidth requirements is essential for sustained operation and economic feasibility. An example is the modular seafloor communications network described — CSnet's Offshore Communications Backbone (OCB). The systems engineering approach that shaped OCB's design, the modeling, simulation, testing as well as data collected during the test and development phases is presented. Subsea networks present the inherent challenge that complete system testing is normally impossible as key elements, such as the telecommunications cable, are only integrated at deployment. Even had the cable been available for integration testing, its reactive properties are different deployed than at a test facility. The potential cost implications of such an unexpected interaction post deployment could result in unrecoverable loss. To mitigate these risks, a rigorous systems engineering approach must be adopted that includes system level studies, analysis and theoretical, numerical and physical models of key areas such as power distribution and communications. The OCB seafloor element consists of both submarine cabling and multiple nodes. The nodes are modularly designed; independent of location and position. The network is redundant and expandable to accommodate additional nodes and buoys. Discussed is the theoretical analysis performed of the system architecture to determine the optimal selection of fiber type and network equipment to ensure robust and reliable communications. Also described is the thorough optical budget analysis conducted taking into account optical link loss, dispersion and optical signal-to-noise (OSNR). Computer simulation and Hardware-in-the-Loop Simulation (HILS) testbeds using the actual hardware being considered in the nodes were employed to validate the theoretical findings. Ethernet benchmark tests were performed to analyze throughput, back-to-back testing, latency and frame loss in the network. Attenuators as well as full scale network fiber lengths measuring hundreds of kilometers were used to test and evaluate multiple fiber types. Results are presented of the power system analysis and transient study utilizing computer models, critical in determining “worst case” voltage and current transients. By using an accurate representation of the cable parameters and system variables, an optimal design of the medium voltage converter (MVC) and high voltage power supply (HVPS) is achieved. Protective measures intended to prevent single point failures, particularly those that may short the backbone cable and bring down the entire network, are evaluated. Physical cable modeling and seawater return analysis were included in the analysis and simulations. Instrument loading (power and data bandwidth) in a hierarchy of combinations intended to simulate the range of possible user applications were simulated to ensure the network's robustness through future expansions. Although the capital expenditure (CAPEX) associated with the rigorous process described of this initial design is significant, the potential cost avoidance and savings over the deployment and operation of both the initial and future network's operational expenditure (OPEX) more than justifies this investment.

Funding, and more specifically the lack thereof, continues to top the list of obstacles that must be overcome in order to enable the full realization of large scale, integrated ocean observing systems and networks. The development and implementation of ocean observatories has primarily been driven by the research community and academic institutions. Almost exclusively, government funding has been relied upon for both fostering the development of individual observatories (the National Science Foundation's OOI - Ocean Observatory Initiative) as well as for the consideration of linking these individual observatories together into national networks (the Ocean.US IOOS - Integrated Ocean Observing System). The IOOS, a multi-agency undertaking, strives to maximize the usefulness and effectiveness of the data generated by its member agencies and is, therefore, oriented toward the development of data products, services and operations. The OOI effort is oriented toward research and providing the instruments necessary to answer effectively the most important research questions facing society. Together, IOOS and OOI represent the United States' contribution to the international Global Ocean Observing System (GOOS) which is in turn, the oceanic component of the Global Earth Observation System or Systems (GEOSS). Another recent development within GEOSS is EMSO (European Multidisciplinary Seafloor Observatories) research infrastructure, representing the launch of a pan-European seafloor observatory initiative. As with the U.S. IOOS, EMSO intends to tie together existing independent observatories into an integrated system. Essential to the EMSO concept is the synergic collaboration between the academic community and industry, striving for both the cost avoidance and potential for revenue generation that might result. Mutually beneficial consortia are actively being sought with both large industrial partners as well as with SMEs (Small and Medium sized Enterprises). As a subset of the international GEOSS initiative, EMSO will also coordinate closely with other similar efforts such as the French-led European Seas Observatory Network of Excellence (ESONET-NoE). Projected cost estimates for implementing EMSO and ESONET-NoE, including cable route surveys, procuring cables, seafloor junction boxes and deploying them is in line with the estimate for implementing the US IOOS. To date, the pace at which each of these major national and international ocean observing initiatives has been set is in large part based upon funding made available through government grants and contracts. This pace may well be accelerated through additional and more meaningful partnerships with industry. The role to be played by the private sector, both large and small companies, is now beginning to emerge. In particular, there appear to be immediate opportunities for mutually beneficial collaboration between the offshore energy enterprise and ocean observing initiatives that have yet to be fully exploited. This paper explores some of the activities already undertaken by industry in ocean observing, both in the U.S. and abroad. Specific instances of industry partnerships are cited as examples of how development and operational costs might be reduced through a modularized approach to designing and deploying ocean observing systems that support both science and industry applications.

Obtaining satisfactory visibility of undersea objects has been historically difficult due to the absorptive and scattering properties of seawater. Mitigating these effects has been a long term research focus, but recent advancements in hardware, software, and algorithmic methods have led to noticeable improvement in system operational range. This paper is intended to provide a summary of recently reported research in the area of Underwater Optics and Vision and briefly covers advances in the following areas: (1) Image formation and image processing methods; (2) Extended range imaging techniques; (3) Imaging using spatial coherency (e.g. holography); and (4) Multiple-dimensional image acquisition and image processing.

*† ‡ A novel, integrated cryogenic flow sensor design is presented in this paper along with experimental results using a surrogate fluid. This design is based on Bragg diffraction from an opto-acoustic grating induced in the flow. Diffraction changes resulting from the Doppler effect are used to estimate the fluid velocity without the need for back or forward scattering from the fluid. This sensor concept provides a robust alternative for use in harsh cryogenic environments, including low and zero gravity conditions, for liquid propellant feed systems and tankage.

Wavelet transforms are commonly used in signal processing to identify local signals in both the time and frequency domain. The application described in this paper uses this concept to show that wavelets of similar DNA sequences converge whereas wavelets of dissimilar DNA sequences diverge. To demonstrate this conclusion, several DNA sequences from different organisms were retrieved form John Hopkins University's Genome Database. Statistical tests were applied to these sequences to measure the degree of similarity. Subsequently, a series of wavelet transforms were applied to the DNA sequences. As a result, the wavelet transforms were found to converge on sequences containing identical proteins and were found to diverge on sequences containing dissimilar ones. A description of the algorithm and statistical tests are provided in addition to analytical results. Application of this wavelet analysis technique has shown to be more efficient than the standard homology search algorithms currently being used. The algorithm has O(Nlog(N)) time complexity whereas standard search algorithms have O(N2) Time complexity. Hence, wavelet transforms can be used to quickly locate or match common protein coding in DNA sequences form large medical databases.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper we describe an approach and present results from a recently developed system that produces video-rate, 3D maps of the image space using a scanning laser configuration and a patented micro-channel plate intensified detector. The scene is viewed from a separate location to provide depth information via triangulation. The detector provides an estimate of position of the apparent landing spot of the laser beam for each scan angle from which a depth estimate is calculated. The system is designed to scan an approximate 15 X 15 degree field-of-view at distances from 1.5 to 2.5 meters with a resolution of 1.5 cm at rates of 10 - 30 full images per second, and can accommodate range gating to reduce scattered light interference.