Ferial El-Hawary, P.Eng., F.IEEE, F.EIC, F.MTS
Tutorials Chair
Oceans '08 MTS/IEEE Quebec Steering Committee
BH Engineering Systems Limited
e-mail: F.El-Hawary@ieee.org

For more information on the tutorial program, please contact the Tutorial Chair, Ferial El-Hawary, at F.El-Hawary@ieee.org.

T1 - Fundamental Underwater Acoustics And Bottom-Interacting Shallow Water Acoustic

This tutorial is intended for engineers and scientists concerned with the assessment of long range acoustic communication and sound transmission in deep and shallow water. The bottom is typically a sandy-sediment and has the dominant influence on the attenuation. The present tutorial surveys the basic science and experimental results that will enable one to make realistic interpretations and predictions. The session plan consists of a primer on the fundamentals of underwater acoustics, beginning with the wave equation, deep-water propagation, shallow water propagation, and the question of standards and a brief overview of ambient noise. The shallow water model of the Pekeris is discussed, progressing to a discussion of the modal solutions for realistic downward refracting sound velocity profiles, with a detailed examination of sample calculations for propagation in range-independent oceans. An assessment and review of representative effects of attenuation and a discussion of the importance of attenuation is presented. Current physical models of ocean sediments are reviewed, beginning with the original phenomenological model introduced by Biot in 1956.  Later evidence justifying and extending this model, especially the rigorous theory of Burridge and Keller in 1981, is reviewed, and the applicable predictions of the theory, such as that the attenuation in the sediment varies as the square of the frequency at low frequencies. The fourth hour is concerned with the field measurements of sediment properties and of how these can be incorporated into propagation predictions.

Presenter Bio - Allan D. Pearce

Allan D. Pierce is Professor of Aerospace and Mechanical Engineering at Boston University and Adjunct Scientist at Woods Hole Oceanographic Institution, and is also the Editor-in-Chief of the Acoustical Society of America (ASA).  He received his doctorate from MIT in 1962, and has subsequently held a variety of research and academic positions, including those at MIT, Georgia Tech, Penn State.  Among his honors are the receipt of the Per Bruel Gold Medal from the ASME, the Rossing Prize in Acoustics Education from the ASA, the Silver Medal in Physical Acoustics from the ASA, and, most recently, the ASA's Gold Medal.  He is perhaps best known in underwater acoustics for his invention of what is now termed adiabatic mode theory, and to the acoustics community at large for his graduate-level text on acoustics.

William M. Carey

William M. Carey is a Professor of Aerospace and Mechanical Engineering at Boston University, an Adjunct Professor of Applied Mathematics at the Rensselaer Polytechnic Institute and an Adjunct Scientist at the Woods Hole Oceanographic Institution. He was the Editor of the Journal of Oceanic Engineering is currently an Associate Editor for Underwater Acoustics, the Journal of the Acoustical Society of America. He has been a Physicist at several the Naval Laboratories and the ASW Program Manager at the Defense Advanced Project Agency. At the University of Chicago's Argonne National Laboratory, he was an Associate Scientist and Section Manager of acoustic surveillance. He has been a consultant to both industry and government in the areas of non-destructive testing, nuclear science/environmental measurements, and applied ocean acoustics. Dr. Carey is a Fellow of the Acoustical Society of America, a Fellow of the IEEE Oceanic Engineering Society, a full member of Sigma Xi, a member of the Connecticut Academy of Science and Engineering, and also a member of the Cosmos Club. He is the recipient of the IEEE-OES Distinguished Technical Achievement Award, the IEEE-OES Distinguished Service Award and an IEEE Millennium Medal. He recently received Pioneer of Underwater Acoustics Silver Medal He received the B.S. degree in Mechanical Engineering, the M.S. degree in Physics, and the Ph.D. degree in Nuclear Science from The Catholic University of America.

T2 - Airborne Hyperspectral Imaging

Hyperspectral data is being increasingly used for many different applications. Its use in  coastal and marine monitoring and mapping has been expanding constantly in the past dozen years. More and more users are being drawn to the use of this complex technology to help address their needs to accurately map coastal resources. Since first being used to map coral reefs in the Turks and Caico’s in 1995, hyperspectral data has been used to map corals in French Polynesia, Indonesia, Indian Ocean, Red Sea, Caribbean and pacific Ocean. Hyperspectral has also been proven as a reliable means to map underwater benthic vegetation, including identifying invasive marine vegetations.

This half day workshop will focus on providing new users an understanding of basic hyperspectral technology. It will be shown how this in turn helps facilitate project planning.  Emphasis will be placed on the pitfalls to be aware of during the planning phase. Attention will also be placed on how an airborne hyperspectral project is actually carried out after the planning is finished.  Despite careful planning there are many difficulties that can arise during data collection and these will be covered in detail.  The introduction of IMU systems with hyperspectral sensors has meant the ability to have very accurate x,y positional information. This in turn has resulted in faster and more accurate mapping capabilities of the hyperspectral data. Advancements in software have meant a better ability to analyze this type of data.

The workshop will cover:

• basic hyperspectral technology
• project planning
• the use of IMU’s
• analysis of hyperspectral data
• mapping hyperspectral data

During the workshop examples from several recent projects undertaken by Mr. Ripley and Hyperspectral Imaging Limited will be highlighted. These projects will include:

• coral reef mapping in Indonesia, Caribbean and Red Sea
• mapping aquatic vegetation in Florida, the Caribbean and Canada
• detecting and mapping invasive marine species in the Mediterranean Sea (France) and Atlantic Ocean (Canada)
  

The workshop goal will be to provide participants with the information needed to successfully undertake a hyperspectral project.

Presenter Bio - Herb Ripley

Herb Ripley is a Canadian citizen and is formally trained in geography and remote sensing. He has been active in the remote sensing/geomatics field for over twenty five years. During that period of time he has had the opportunity to work on numerous projects at a regional, national and international level. Herb is President of Hyperspectral Imaging Limited. (HIL), a firm where approximately 50% of its project work is done internationally. Many of the projects undertaken by HIL have a strong coastal and/or environmental focus, i.e. mapping the Peruvian rainforest for an environmental impact assessment, mapping coastal areas of St Lucia to determine the impact level of human activities or studying the effects of El Nino on coral reefs in French Polynesia. HIL also provides high resolution digital photography and HIL works mainly within the forestry, agriculture and engineering communities. Herb has been an invited lecturer on remote sensing at local, national and international educational institutes, has published numerous technical papers at international scientific conferences and has been recognized by the Remote Sensing Society (U.K. based) by being named a Fellow. Herb is or has been a strong participant in such industry groups as the Geomatics Industry Association of Canada (GIAC) (served as Board member), the Geomatics Association of Nova Scotia (GANS) (Director, Vice President and President), the Alliance for Marine Remote Sensing (AMRS) (sat on the organizing committee) and was most recently AMRS's President. In 1995 he was the founding President of the revitalized Champlain Institute and served a second term as President. Herb was recently elected the Chair of the Marine Technology Society's Remote Sensing Committee.

T3 - Applied model-based signal processing: Classical, Modern and Bayesian Techniques

Topics presented in this tutorial include:

Modeling & simulation

• Introduction (background, estimation, model-based signal processing, deterministic state-space modeling)
• Stochastic modeling (random linear systems simulation, gauss-markov state-space modeling and simulation)
• Estimation (properties, performance, minimum variance estimation, ml, map estimation)

Model-based processing (kalman filtering)

• Introduction (overview, innovations approach, innovations sequence analysis)
• Practical aspects i (heuristics, tuned mbp, tuning parameters)

Model-based processing extensions

• Extensions (nonlinear (approximate) modeling, linearized mbp, classical nonlinear (extended) mbp)
• Extensions (nonlinear processing, modern unscented mbp)
• Extensions (nonlinear bayesian processing, particle-based mbp)
• Applications (ocean acoustics)

Master copies of the viewgraphs will be provided to the participants.

Presenter Bio - Dr. James V. Candy

James V. Candy is the Chief Scientist for Engineering and former Director of the Center for Advanced Signal & Image Sciences at the University of California, Lawrence Livermore National Laboratory. He has published over 200 journal articles, book chapters, and technical reports as well as written three texts in signal processing, "Signal Processing: the Model-Based Approach," (McGraw-Hill, 1986) and "Signal Processing: the Modern Approach," (McGraw-Hill, 1988), “Model-Based Signal Processing,” (Wiley/IEEE Press, 2006) with a fourth entitled “Bayesian Signal Processing: Classical, Modern and Particle Filtering” (Wiley/IEEE Press, 2008) in press.

His research interests include Bayesian estimation, identification, spatial estimation, signal and image processing, array signal processing, nonlinear signal processing, tomography, sonar/radar processing and biomedical applications.

T4 - AUV Technology and Application Basics

AUV Application Basics is a short course that provides an overview of current AUV technologies and operations. The objective is to establish a basic understanding of what currently available AUV systems can provide and what are best practices in use. The class is targeted at scientists interested in using AUVs for oceanographic applications. The attendee will gain basic understanding of AUV types, technologies, terminology, and navigation techniques, including discussion of the comparative strengths of AUVs and alternative methods of data collection. The attendee will also be provided an understanding of tradeoffs in AUV operations, including power estimation, endurance considerations, and mission structure to acquire the desired data sets. Key points are illustrated by applications and results from the Monterey Bay Aquarium Research Institute's (MBARI) Dorado AUV and other AUV operations. Topics include: Basic AUV technology, AUV at-sea Operation, Payload Considerations, Mission Planning, Upper and Mid-Water AUV missions, Benthic and Mapping AUV missions, Data Collection and Reduction, AUV Integration into Sampling Networks, and a look at coming AUV advances. The interactive format, using the materials provided, allows the attendee discussion time for relevance and demonstration purposes regarding real or potential AUV plans.

Intended Participants
This class is intended for scientists interested in applying AUVs to particular problems, persons interested in AUV applications and the impact of AUV technology, as well as graduates in oceanographic fields seeking a broad understanding regarding the application of AUV platforms.

Presenter Bio - William J. Kirkwood

Bill is currently the Associate Director of Engineering at the Monterey Bay Aquarium Research Institute (MBARI) located in Monterey Bay, California. Bill has a BS in Mechanical Engineering and a MS in Computer Science which he has applied to controls and automation of electromechanical systems and robotics since 1978. Bill has been with MBARI for 16 years as a lead mechanical engineer and program manager developing the Tiburon remotely operated vehicle and Dorado class autonomous underwater vehicles. Bill focus currently is developing underwater instrumentation for science to look at hydrates and anthropogenic CO2 ocean acidification issues.

T5 - Design of synthetic aperture sonar systems for high resolution seabed imaging

This tutorial will review the key aspects of the design of synthetic aperture sonar (SAS) systems for high resolution seabed imaging. After a quick overview of the expected benefits and main features of SAS, the design of the transmitter and receiver arrays will be discussed, with emphasis on the mitigation of spatial aliasing with multi-element receiver arrays, wideband operation and extension to interferometric SAS for estimating the seabed bathymetry.

Next the most difficult issue in SAS, which is the micronavigation problem i.e. that of estimating the unwanted platform motions with the required sub-wavelength accuracy, will be addressed in detail. The emphasis will be on methods which have proved their value at sea, which combine inertial navigation systems (INS) with data-driven methods based on the Displaced Phase Centre Antenna (DPCA) technique. The topics covered will include the theory of spatial backscatter coherence, the derivation of ping to ping motion estimates using time delay estimation theory, including the use of bandwidth for phase unwrapping and the appropriate range-dependent near field corrections to arrive at unbiased estimates, the establishment of the Cramer Rao lower bounds for motion estimation which demonstrate the need for fusion with an INS to achieve full performance. The geometrical relationship between the DPCA and INS projection frames, which is necessary for accurate fusion, will be established and shown to depend also on the local seabed slope. The estimation of this slope with interferometric sonar will be discussed.

Furthermore the impact of the environment and in particular of the multipath structure in large range to water depth ratios will be discussed. Multipath will be shown to degrade the quality of the SAS imagery as well as adversely impact the accuracy of interferometric estimates including DPCA. Means to mitigate multipath operation by management of the vertical transmission and reception beams will be discussed, showing experimental results which point to some of the limitations of existing sonar performance prediction tools.

Finally different design tradeoffs between computational efficiency and robustness for micronavigated SAS imaging algorithms will be discussed and an example of a real-time implementation suited for operation on-board an autonomous underwater vehicle will be described.

Presenter Bio - Marc Pinto

Marc Pinto was born in Wellington, India in 1960. He graduated from the Ecole Nationale des Ponts et Chaussées, Paris (France) in 1983. From 1985 to 1989 and 1989 to 1993 he worked as a research engineer for Thomson-CSF, specializing in the development of finite element techniques for solving non-linear magnetostatics to support the modeling of the magnetic recording process. In 1991, he received the Ph.D. degree in Solid State Physics from the University of Paris, Orsay. In 1993 he joined Thomson-Sintra ASM (now Thales Underwater Systems) as Head of the Signal Processing Group, specializing in research into advanced MCM and airborne ASW sonar. In 1997 he joined the NATO Saclant Undersea Research Center, La Spezia, Italy as principal scientist. He was appointed Head of the Mine Countermeasures Group, in the Signal and Systems Division in 1998 and held this position until the Group was dissolved in 2000. From 2000 to 2004 he conducted, as project leader, research into synthetic aperture sonar systems for hunting proud and buried mines. In 2004 he was appointed Head of the Expeditionary MCM and Port Protection Department where he presently oversees the research into AUV-based mine-hunting, electronic mine countermeasures and harbour defence.

T6 - Array Processing and Beamforming

This tutorial is an introduction to different ways for processing data coming from arrays. These processed data can be used to create image of an illuminated scene, to detect some target (through angle and range) or to create a 3D model of the scene. The main idea of this course is not to make a catalogue of methods but really to emphasize on the difficulty for radar or sonar to determine the wave front arriving angle on an array. Thus, this tutorial is divided into three parts:

• The first part is an introduction to the problem and potential applications. The hypotheses used for modeling are detailed ranging from stationarity of the spatio-temporal field, noise decorrelation, type of arrays, ….
• The second part deals with traditional beam forming showing how it works but also its limitations. The beam forming can be expressed under constraint with ratio noise level (i.e. Capon algorithm) or under more precise constraints (i.e. GSC algorithm).
• The third part is about high resolution methods and mainly about why and when these methods can be used. A parallel is made with the interferometric approach, and to compare both. The most known method, Music (Pissarenko algorithm), is detailed and several interesting points are investigated such as wide band signals, noise correlation etc.

This tutorial is a rapid description of several techniques for processing data along with their hypotheses. Finally, applications and examples conclude the tutorial.

This tutorial is intended for people or scientists connected with signal or array processing, and interested to have a fly-over about these commonly used methods.

Presenter Bio - Christophe Sintes

Christophe Sintes graduated from « École Nationale des Études et Techniques d’Armement », Brest 1992. From 1995 to 1998, he worked for the French Hydrographic Services as electronics chief of the Atlantic Hydrographic Mission. He joined the GESMA (Groupe d’Études Sous-Marines de l’Atlantique) in 1998 and received a Ph.D degree in electronics from the Université de Rennes, France in 2002 about high resolution interferometric processing for mine hunting. In 2002, he also joined the “École nationale des Télécommunications” as Associate Professor in the remote sensing group. He works now on array processing for radar and sonar.

Presenter Bio - Didier Guériot

Didier Guériot (M'95) graduated from “Institut National des Sciences Appliquées” (INSA), Rennes, France in 1991 where he studied computer science. In 1999, he received the Ph.D. degree in electronics at the University of Haute Alsace, France, focusing on extending genetic algorithms to variable length solutions for difficult problems such as neural networks learning and symbolic sonar image registration. From 1993 to 2005, he had been working as R&D Engineer for several research labs and companies within the sonar field, dealing with high resolution sonar imagery for GESMA (“Groupe d'Études Sous-Marines de l'Atlantique”, a French navy research agency) and multibeam echosounders for RESON in Santa Barbara, California. In 2005, he joined “ENST Bretagne” (École Nationale Supérieure des Télécommunications) in Brest, France as an associate professor. His research interests range from sonar data processing to artificial intelligence applied to underwater environment reconstruction.

T7 - Synthetic Aperture SONAR Image Despeckling

Over the past few years, more and more accurate positioning, imaging and cartography systems have been created. Synthetic Aperture SONAR (SAS) systems are good illustrations, since they offer images of great accuracy.

The active synthetic aperture SONAR is a high-resolution acoustic imaging technique that coherently combines the returns from multiple pings to synthesize a large acoustic aperture. Thus, the azimuth resolution of a SAS system does not depend anymore on the length of the real antenna but on the length of the synthetic antenna. Consequently, in artificially removing the link between azimuth resolution and physical length of the array, it is now possible to use lower frequencies to image the sea bed with a good resolution. Therefore, lower frequencies are less attenuated and long ranges can be reached. All these advantages make SAS images of great interest, especially for the detection, localization and eventually classification of objects lying on the seabed. But, as any image obtained with a coherent system, SAS images are highly corrupted by a granular multiplicative noise, called the speckle noise. This noise, by giving a variance to the intensity of each pixel, reduces spatial and radiometric resolutions. Such a noise hinders the interpretation and the automatic analysis of SAS images. For this reason a large amount of research works have been recently dedicated to reduce this noise and suppress the spacious reflections affecting the images, with two main goals: the strong reduction of the speckle level and the spatial resolution preservation. To respect these two constraints, a compromise has to be done, given that, for the most the classical approaches, a strong denoising affects the spatial resolution by a smoothing effect.

A review of the different techniques, found in the scientific literature, reveals that it is possible to classify these methods in various categories: the scalar filters (mean filters, median filters, …), the adaptive filters (Lee filters, Frost filters, …), the MAP filters (Gamma filter, Fisher-MAP filter, …), the image-domain filters (wavelet approaches, stochastic matched filter, …). All these methods give good results depending on the criteria used to quantify the quality of the despeckled data. Furthermore, to properly evaluate a despeckling process, it is also of great interest to take into consideration the number of input parameters, the necessary a priori knowledge of signal and noise, the algorithm complexity and implementability. Because of the high number of filtering methods coupled to the number of criteria, it appears of great interest to be able to classify these despeckling methods for each considered criterion, in order to allow the user to determine the most convenient method answering his specific problem (classification, localization, …).

The purpose of this tutorial is to present a review of SAS images denoising methods (up to 40 techniques) using several criteria (up to 10 criteria) from spatial resolution preservation to speckle noise reduction to algorithm implementability.

Presenter Bio - Philippe Courmontagne

Philippe Courmontagne was born in 1970. He received the Ph. D. degree in Physics at the University of Toulon (France) in 1997. In 1999, he became Professor in a French electronic engineering school: the Institut Supérieur de l’Électronique et du Numérique (ISEN Toulon, France), in the field of signal processing and image processing. He joined in 2001 the Provence Materials and Microelectronics Laboratory (L2MP UMR CNRS 6137), which is a unit of the French national research center (CNRS). In 2005, he obtained his Habilitation (HDR - Habilitation to Supervise Research) for his works in the field of noisy signal expansion. In 2007, he has been elected to the degree of IEEE Senior Member in recognition of professional standing for his works in the field of signal de-noising (SAR, SAS images), signal detection in noisy environment and signal transmission. In 2008, he will be the chairman of a workshop (PASSIVE’08), sponsored by the IEEE Oceanic Engineering Society, in the field of passive systems for oceanic observations.

T8 - Atmospheric effects on visible and infrared imaging in marine Environments

This tutorial provides a broad description of the atmospheric phenomena that affect imaging systems in the visible and infrared spectrum in marine environments. Effects of atmospheric transmission and radiance, refraction and turbulence are described in details and many examples are shown. Emphasis is given to medium-to-long range imaging at low levels above the ocean. We present physical models and current computational tools designed to describe and predict the effects on imaging systems as a function of the prevailing meteorological conditions. Reliability and accuracy of current models are discussed for the various effects. The physical quantities needed for system performance studies are introduced.

This tutorial is intended to anyone wishing to be acquainted with the atmospheric phenomena that affect imaging quality, and to know about available models to describe or predict the effects. Basic knowledge in physics, especially in light propagation, would help to understand the various principles involved.

Presenter Bio - Denis Dion

DENIS DION received the B.S. and M.S. degrees in Electrical Engineering from Laval University (Québec, Qc, Canada) in 1980 and 1983, respectively. He joined the Defence Research & Development Valcartier (DRDC Valcartier) in 1982 to conduct research in the field of modeling and simulation of radar and electro-optical sensors. His work has been mainly oriented towards the characterization and modeling of environmental effects on sensor performance in the maritime environment, with emphasis on propagation effects near the sea surface. He is author and co-author of many papers on the subject.