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We present a next generation seismic source. The Tuned Pulse Source is a new pneumatic seismic source designed to operate with low-pressure air. It releases a large volume of air into the water over a controlled time generating a pulse with a long rise time and a bubble with a long period. The long bubble period produces strong low frequency signal for velocity model building with methods such as Full Waveform Inversion, for imaging subsalt and sub-basalt, and for building blocky reservoir models using Inversion. Compared to airguns, the TPS has a stronger low frequency content and a lower environmental impact.

A non-coherent multiple input multiple output (MIMO) coded communication system over a frequency selective (FS) block fading channel is considered. A theoretical limit for the channel estimation error is established via a closed form derivation of the modified Cramer-Rao bound (MCRB) (more precisely, a tight lower bound to it) for the underlying channel model and equi-power signal constellations. Furthermore, it is shown that, for a practical coded MIMO system that employs turbo coding and an appropriate iterative decoding, the resulting mean squared error (MSE) in channel estimation approaches very closely to the derived theoretical limit.

A noncoherent multiple antenna coded communication system over both block fading and time-selective flat fading Rayleigh channel is considered. Several iterative decoding strategies consisting of pilot symbol assisted demodulation and turbo decoding are proposed. It is shown that, at a system rate of 0.9 bits per channel use, the SNR required to achieve a BER of 10−4 is only about 2dB from the imperfect CSI capacity lower bound. The channel estimation error variance is demonstrated to be close to the theoretical limit set by the Modified Cramer-Rao bound. The simulation results coincide with the trends dictated by recent information-theoretic analysis and demonstrate the effect that inaccuracy of the channel estimation has on the performance of the iterative decoding scheme. Copyright © 2007 John Wiley & Sons, Ltd.

This work proposes a technique for deriving fast finite-difference algorithms for numerical modelling of acoustic wave propagation in anisotropic media. The technique is deployed in the case of transversely isotropic media to implement a kinematically accurate shear-free fast finite-difference modelling method. This results in a significant reduction of pseudo-shear artifacts compared to similar kinematically accurate finite-difference methods.

Gaucher's disease is the most prevalent sphingolipid storage disease, characterised by substantial genetic and phenotypic variability. Cardiac manifestations are rare. We report 12 Arab Gaucher's disease patients, 2-20 years of age, who presented with oculomotor apraxia but only slight classic signs of the disease. All but the youngest had calcifications of the aortic or mitral valves or both. All these patients were homozygous for the rare point mutation D409H (1342C). Valvular calcifications increased with age and showed progression during 2 years of follow-up. Two of the oldest patients underwent aortic valve replacement, and one sibling had died suddenly at age 16, before this study, Corneal opacities were another common feature. The potentially fatal course of this Gaucher's disease variant, and the availability of a reliable PCR-based method for heterozygote detection, mean that population screening and genetic counselling in the geographic area at risk are important. Affected individuals should be closely monitored by echocardiography to gauge the need for valve replacement. The potential of enzyme replacement to prevent these cardiac complications cannot be ascertained at present, because of the high cost of therapy.

Vector fidelity is the ability of a given sensor to record the motion of the seabed as if the sensor was not there. Hence, vector infidelity may come from either poor coupling or from an influence of the sensor package on the seabed around it. To study the implications of ocean bottom node design on coupling and vector fidelity, we analyse data from a field experiment in which several types of nodes have been deployed at close proximity. The data provide a good opportunity to compare the effect of the shape and design of a node on the quality of the data it provides. We have data from nodes with internal and with external sensors, from nodes which are planted, from nodes that are gravitationally coupled, and from nodes with different contact area, and height of centre of inertia. We find variations in the data that are consistent with the node design. We analyse the amount and the form of shear-wave induced noise on the vertical component and of P-wave induced noise on the horizontal components.

The combined use of Bragg grating and dielectric sensors has been studied for the monitoring of bonded composite repairs to metallic parts, using standard composites field repair equipment and specially built "sensing mats" Measurements retrieved via a variety of sensors were correlated, to analyze the interactions of the chemical and physical changes occurring during the bonding process. It was concluded that the combined use of Bragg gratings and dielectric sensors can provide important information for the cure monitoring of bonded composite repairs.

We report on measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate. A magnetic-field Feshbach resonance is used to tune atom-atom interactions in the condensate and to reach a regime where quantum depletion and beyond mean-field corrections to the condensate chemical potential are significant. We use two-photon Bragg spectroscopy to probe the condensate excitation spectrum; our results demonstrate the onset of beyond mean-field effects in a gaseous Bose-Einstein condensate.

We report on measurements of the excitation spectrum of a strongly interacting Bose-Einstein condensate. A magnetic-field Feshbach resonance is used to tune atom-atom interactions in the condensate and to reach a regime where quantum depletion and beyond mean-field corrections to the condensate chemical potential are significant. We use two-photon Bragg spectroscopy to probe the condensate excitation spectrum; our results demonstrate the onset of beyond mean-field effects in a gaseous Bose-Einstein condensate.

A non-coherent multiple input multiple output (MIMO) coded communication system over frequency selective block fading channel is considered. A theoretical limit for the channel estimation error is established via a closed form derivation of the modified Cramer-Rao bound (MCRB), for the underlying channel model and equi-power signal constellations. Furthermore, a specific coded MIMO system with an appropriate iterative receiver is studied, and the mean square error (MSE) in the channel estimation with the proposed structure is demonstrated to asymptotically approach the derived theoretical limit.

Summary A new design of ocean-bottom seismometer (OBS) system has been developed and tested that can provide high quality data in challenging deep-marine exploration and production areas. Each node records the pressure signal with a hydrophone and three components of seabed motion using geophones. The new units are self-contained recording stations, and are deployed by a remotely operated vehicle (ROV). They record seismic data on the seafloor for an extended period while a source vessel shoots lines above. Because they are autonomous, there are no cables joining the stations together. The nodes are therefore well-suited to working in congested waters, even right up to, or perhaps under, production structures. They also render 4D surveys practical because the ROV can redeploy the units close to their previous sites to ensure a high level of repeatability. The new nodes are differentiated from other types by improved levels of safety and efficiency; this is inherent in the compact, long-endurance, integrated modular design. The units also deliver high vector-fidelity thanks to excellent coupling to the seabed. We discuss the considerations, compromises, development and testing of these new OBS units.

A key principle for understanding and interpreting seismic images of the subsurface is that seismic waves are sensitive to three bulk rock properties: compressibility, rigidity and density. Recording both P-wave and S-wave modes allows better separation of these three properties. S-wave propagation is sensitive only to rigidity and density, while compressional-wave propagation is sensitive to rigidity, density and compressibility. Therefore, P-waves tend to have a higher sensitivity to fluids in the pore space. On the other hand, open fractures more strongly affect rock rigidity and since Swaves are more sensitive to rigidity changes, they are more suited for fracture characterization. Interpreting both P- and S-wave reflectivity offers the ability to discriminate lithology, porosity, fractures and possibly fluid content. However, a number of barriers historically inhibited the acceptance and growth of multicomponent technology.

Ocean Bottom Stations provide wide-azimuth multi-component data with great advantages for exploration, reservoir characterization, and identification of drilling hazards. However, due to the high cost of deploying OBS nodes, large receiver intervals are used. In practice, poor illumination due to sparse receivers is a major problem. This problem is particularly, but not exclusively, associated with gaps in the coverage of shallow targets, and is greatly exasperated if some OBS nodes fail. The same problem affects both sparse OBS nodes and ocean bottom cables in the cross-line direction. Fortunately there is an effective solution. The first step in our method is the separation of seabed hydrophone and geophone data to upgoing and downgoing waves. Downgoing waves just above the seabed contain only multiples, or ghost reflections. Nevertheless, we image the ghosts, pretending that the data were acquired with a certain equivalent geometry recorded above the sea surface. This alternate surface is the top of a virtual water layer whose thickness is twice the sea depth. We applied this method to OBS data recorded in the North Sea and generated better images from the downgoing ghosts than the images produced conventionally from the primary upgoing waves.

Good vector fidelity is crucial for various multicomponent applications and can be adversely impacted by poor sensor coupling during data acquisition. We present a method to evaluate the ground coupling quality of three-component (3C) sensors during field deployment using ambient seismic noise data. The method utilizes the directional nature of the noise on the three sensor components for coupling assessment. This is believed to be the first method developed to evaluate in situ sensor coupling from ambient noise measurements.

Surface-consistent residual static correction is applied to land data on a routine basis. However, if the statics are large, conventional methods often break down due to, among other reasons, the difficulty to construct a good pilot trace. We developed a large static correction method that constructs the pilot trace by a local robust L1-norm inversion at each CDP location. The local inversion calculates the relative time shifts of the traces within a CDP gather by minimizing the trace-to-trace time difference. A pilot trace is obtained by stacking the CDP gather after aligning the reflectors by applying the time shifts to the traces. Finally, a global L1-norm inversion resolves the source and receiver statics from the time shifts of traces of all CDP gathers relative to their pilot traces. The method is demonstrated with synthetic and real data examples.

P076 Estimating and correcting of tilted multicomponent receivers Abstract 1 We developed a new and simple algorithm for multi-component receiver tilt correction. We estimate the receiver tilt and orientation angles using seismic data by finding such angles that best make the data from all the shots consistent. It has been successfully applied in tilt angle estimation on VSP and tilt correction on seabed field data. Introduction Correction of tilted multi-component (MC) receivers has become a routine and must-do process in MC data processing because it is impossible to plant all MC receivers perfectly vertical on both land and seafloor. Unless

1 A18 AN SVD-POLARIZATION FILTER FOR GROUND ROLL ATTENUATION ON MULTICOMPONENT DATA R. KENDALL 1 S. JIM 1 S. RONEN 1 K. DE MEERSMAN 2 1 Veritas Suite 2200 715 – 5 th Avenue SW Calgary Alberta Canada T2P 5A2 2 School of Earth and Environment University of Leeds Leeds LS2 9JT UK Summary By their very nature multicomponent data provide information on the full wavefield and therefore offer new full-wavefield solutions for the ground roll problem. Here we introduce a time domain multicomponent Singular Value Decomposition (SVD) polarization filter that is optimized to remove most ground roll energy while

A non-coherent multiple antenna coded communication system over both a block fading and a time-selective flat fading Rayleigh channel is considered. Several iterative decoding strategies consisting of pilot symbol assisted demodulation and turbo decoding are proposed. It is shown that, at a system rate of 0.9 bits per channel, the SNR required to achieve a BER of 10/sup -4/ is only about 2 dB away from the imperfect CSI capacity lower bound. The channel estimation error variance is demonstrated to be close to the theoretical limit set by the modified Cramer-Rao bound. The simulation results coincide with the trends dictated by recent information-theoretic analysis and demonstrate the effect that the inaccuracy of the channel estimation has on the performance of the iterative decoding scheme.

We investigate the problem of an electron placed in the potential of a finite dipole and confined by an impenetrable prolate spheroidal box. The critical cage sizes at which successive bound states are ionized as the box becomes smaller are found to be the roots of associated Legendre functions of complex order. We find the asymptotic behavior for a large cage. The lowest few roots are computed numerically. Comparison is made with the case of an electron bound by an ideal dipole plus short-range repulsion, confined in a spherical box.

C-37 COMBINED OCEAN BOTTOM STATIONS AND SURFACE TOWED SEISMIC STREAMERS Abstract 1 We propose to combine sparse multi-component (MC) seismic data with dense single component (1C) data. Such combination of both acquisition operations and data analysis can provide a better value/cost ratio compared to either 1C data alone or MC data alone. Introduction S. RONEN A. RATCLIFFE P. NICHOLS K. MILLS R. LEGGOTT K. HAWKINS and L. SCOTT VeritasDGC Crompton Way Manor Royal Estate Crawley West Sussex RH10 9QN UK MC seismic data have been acquired on the seabed for over a decade. Compared to surface towed streamers such data

A-12 OVER/UNDER ACQUISITION – BREAKING THE RESOLUTION LIMITS S. GRION J. HOBRO J. BARSCH and S. RONEN Summary 1 Seismic resolution is limited by source and receiver ghosts. In marine acquisitions shallow source and receivers increase high frequency content but attenuate the low frequencies fundamental for stratigraphic and structural inversion. On the other hand deep source and receivers enhance the low frequencies at the expense of the high. The combination of data acquired with different cable depths is a solution to this problem and is usually referred to as over/under combination. Over/under can combine in a single image the high-frequency

Abstract Imaging sub gas has been shown to be a robust application of 4-componentseabed seismic. We review the acquisition and processing of an orthogonal(source lines perpendicular to receiver lines) 4-component 3D survey over the Lomond Field in the North Sea. The geophysical objectives were to improve theimaging of faults and the crest of the structure under the gas cloud, where theconventional seismic is distorted. Conventional streamers record only the pressure waves and suffer from verylow signal/noise ratio and pull-down under the gas cloud. It is recognized thatconverted shear waves are largely unaffected by fluids and the success ofearlier 2D lines e.g. Tommeliten (Berg et al.1) provided some of the motivationfor acquiring the 3D Lomond survey. A multi-component cable system was laid on the seabed to record bothpressure and converted wave data in a cross spread geometry. In total, fivepairs of cables were laid giving a seabed footprint of 36 sq.km. The cablesystem uses array's of hydrophones with 3 orthogonal velocity sensors. In processing, the hydrophone and vertical velocity sensor are summed togive an improved result. The horizontal velocity components are rotated intoradial and transverse components and the radial data is processed as aconverted shear wave. Multi-component methods have been developed, including NMO, DMO and binning, to improve converted wave processing. The orthogonalgeometry records ray-paths from all azimuths presenting some challenges toprocessing. Processed results will contrast the final migrated pressure wave andconverted wave images. The first shows good imaging of the steep flanksegments, distortion under the gas-invaded zone and poor event continuity inthe crestal feature. The second shows similar structure and good continuityunder the gas. Introduction to the Lomond 4C Project The use of 4-component seismic to solve the problem of imaging beneath gaszones has been shown to be a robust application. However orthogonally acquireddata presents some new challenges to processing. Conventional seismic records pressure waves (or Primary waves), the seabedsystem can also record transverse shear waves (or Secondary waves), these arecommonly called P-waves and PS-waves.

Abstract Acquisition downtime resulting from bad weather is often a significantfactor in the cost of marine seismic surveys. In the North Sea, for instance, seismic data are acquired mostly during the summer, and weather downtime canstill amount to 40% of the survey time. Our approach to reducing weather downtime is based on the followingconcepts:During multiple acquisition passes, seismic signal is repeatable; badweather noise is not.Filtering algorithms are applied to reduce swell noise.Imaging with least-squares inversion algorithms is less sensitive tonoise-edited data than conventional imaging. To test these concepts we acquired multiple pass data covering the sameareas in good and bad weather. A survey was made from the Barents sea and theacquisition was performed with a vessel equipped for standard 3D surveys. Commercial 3D data provide a reference for quantitative comparison ofseismic images and of attributes derived from the seismic data. The resultsobtained so far are encouraging, and we expect opportunities for cost-effectivereduction of bad weather downtime (10% to 20%) without compromising qualityrequirements. Introduction The purpose of this work is to process and combine data from multi-passacquisitions during bad weather conditions to obtain a reliable image of thesubsurface. The survey acquired with this aim had 6 streamers each 3 Km long, towed at 7m nominal depth, with an overall separation of 750 m. Dual 3707 cubic inchessources with 75 m separation at a depth of 6 m were fired every 25 m. Thenumber of channels per cable was 240 with 12.5 m group spacing. During recording in bad weather, the streamers were towed at 7-8 m depth. Maintaining seismic instruments in their nominal positions by varying sourceand streamer depths was identified as an important aspect of the survey design. In practice acquisition in bad weather was stopped when the swell noise was sohigh that it pulled the streamers up to the surface.

Swell noise resulting from bad weather conditions may obscure important reflections in the data and must be avoided or removed prior to further processing. We observe that such noise is mostly limited to low temporal frequencies and appears as spatially incoherent when recorded with conventional streamers. In this paper we propose to acquire multi-pass data in moderately bad weather, and try to filter and combine the acquired data and produce acceptable output. Perhaps, a few passes in bad weather can provide enough data to produce a good image.

Long offset streamer data (up to 18 km) and four component (4-C) sea bed data frorn the East Faroes Basin have recently been acquired by Geco-Prakla.

Educating engineers and architects in Illumination Engineering and related subjects has become a very important field and a very satisfying and rewarding one. Main reasons include the need to significantly conserve lighting energy and meet government regulations while supplying appropriate light levels and achieving aesthetical requirements. The proliferation of new lamps, luminaries and lighting controllers many of which are 'energy savers' also helps a trend to seek help from lighting engineers when designing new commercial and residential buildings. That trend is believed to continue and grow as benefits become attractive and new government conservation regulations take affect. To make things even better one notices that Engineering and Science students in most disciplines make excellent candidates for Illumination Engineers because of their background and teaching them can move ahead at a brisk pace and be a rewarding experience nevertheless. In the past two years, Cal Poly Pomona College of Engineering has been the beneficiary of a DOE/California grant. Its purpose was to precipitate and oversee light curricula in various California community colleges and also develop and launch an Illumination Engineering minor at Cal Poly University. Both objectives have successfully been met. Numerous community colleges throughout California developed and are offering a sequence of six lighting courses leading to a certificate; the first graduating class is now coming out of both Cypress and Consumnes Community Colleges. At Cal Poly University a four course/laboratory sequence leading to a minor in Illumination Engineering (ILE) is now offered to upper division students in the College of Engineering, College of Science and College of Architecture and Design. The ILE sequence will briefly be described. The first course, Introduction to Illumination Engineering and its laboratory are described in more detail alter. Various methods of instruction including lectures, self work, industrial visits and guest lectures, as well as the accompanying laboratory work are discussed. Feedback from the students was very positive.

Irregular acquisition geometry is inevitable due to obstacles and cable feathering in 3-D marine surveys and access limitations in 3-D land surveys. The irregularities will damage the fidelity of seismic images, unless they are properly handled in the processing. DMO in particular, must take account of the actual geometry. Black, Schleicher, and Zhang (1993) have developed an anaiytical calibration method that is implemented via the DMO amplitude term. In this paper we extend the DMO calibration to take into account the irregular geometry, and develop a geometrical calibration.

A pressure buildup well test is a measurement of bottomhole pressures in a wellbore beginning while the well is flowing and continuing for a period of several hours or days after the well is shut in . After the well is shut in, no force maintains the low pressure at the well and the tendency toward equilibrium results in a buildup of pressure in the wellbore. The pressure perturbation initiated by shutting in the well, expands about the well, and trends in the measured wellbore pressures may be altered whenever the pressure wave encounters a change in rock or fluid properties .

A case of unilateral exophthalmos with ophthalmoplegia and papilledema which developed 1 week after culture-proven Shigella sonnei dysentery is described. The clinical course with improvement of the patient's eye findings as well as systemic condition on appropriate antibiotic therapy probably demonstrate the relationship between the the dysentery and subsequent orbital inflammation.