Andrey K Morozov

Teledyne Technologies · TWR

The presentation describes the design and test of innovative deep water low frequency sound source for long range acoustic communications and navigation. The light-weight, low frequency (200-1000 Hz), broadband underwater sound source comprises an inner resonator tube with thin walls tuned to a certain frequency surrounded by a shorter, larger-diam...

In the last two decades, we have witnessed growing research interest in underwater communications and networks for both civilian and scientific, as well as, military type of applications. Despite the plethora of studies in this area many issues are still remain to be solved due to the challenging nature of the propagation medium. The underwater aco...

This paper proposes a receiver for direct-sequence spread spectrum transmissions in underwater acoustic channels, which combines a per-survivor processing (PSP) structure with sparse channel estimation. Specifically, the PSP structure establishes the trellis on the symbol level to render a small to moderate number of states, thus reducing the compu...

The state-of-the-art in high-rate, single-carrier wideband signaling for acoustic communications is represented by the decision feedback equalizer (DFE). Though often effective, its performance is far from the optimal obtained from soft decision maximum a posteriori probability (MAP) and maximum-likelihood sequence detectors (MLSD). While these alg...

Second- and fourth-moment mode-amplitude statistics for low-frequency ocean sound propagation through random sound-speed perturbations in a shallow-water environment are investigated using Monte Carlo simulations and a transport theory for the cross-mode coherence matrix. The acoustic observables of mean and mean square intensity are presented and...

The efficiency of underwater low-frequency sound sources can be improved by using tunable high-quality resonators, increasing the emission aperture, or using source clusters. A very low frequency tunable resonator is hard to build. Large aperture sources are difficult to deploy. This study shows that the efficiency of a cluster of sources can be mu...

Experiments with a gas-filled adiabatic bubble resonator of large diameter have shown that it is an efficient emitter of low-frequency seismic waves. The resonator has a single resonant frequency with a narrow bandwidth. The internal acoustic resonant structure changes the frequency response of the entire source and makes it possible to expand its...

The use of coherent broadband signals instead of explosive, high-intensity air-gun pulses is one potential way to reduce sound pressure and sound exposure levels in marine surveys. A coherent type of seismic source achieves a higher resolution, hence a sharper image of deep layers. In the upper-frequency range of seismic signals (higher than 16 Hz)...

No PDF available ABSTRACT Low-frequency sound sources have found application in oceanology and geoacoustic methods of remote sensing. An underwater low-frequency sound source with a pneumatically driven bubble resonator covered with an elastic membrane effectively provides a very high source level. However, it has a narrow bandwidth, and its resona...

The ultra-low frequency band (2–8 Hz) is of interest for geophysical research due to advances in the field of full waveform inversion and elastic impedance measurements. Generating sound in the ultra-low frequency range is a difficult task. A powerful source with an ultra-low frequency should be able to displace hundreds of liters of water per cycl...

No PDF available ABSTRACT The reducing impact of noise from traditional air-guns on marine mammals is an actual problem for oil and gas producers. The application of coherent, broadband signals instead of explosive, high intensity, and air-gun pulses is the potential way of noise mitigation. The three major oil companies, Shell, Exxon, and Total, a...

The fluid dynamics of large oscillations of air-filled bubble in the water is defined in general by Navier-Stokes equation for compressible liquid. When the bubble is spherical the problem turns into a one-dimensional Rayleigh-Plesset equation. The buoyancy deforms the shape of a real bubble from spherical. The gravity makes the problem three-dimen...

Three major oil companies, Shell, Total and Exxon Mobile, are sponsoring a Marine Vibrator Joint Industry Project (MVJIP), Mougenot et al. (2017). Marine Vibrators are a coherent type of seismic source, which are considered to be less harmful for marine inhabitants and give a clearer, more precise and higher resolution image of subsurface formation...

Arctic acoustic tomography, requires a broadband source in the frequency range of 5-100Hz. To meet this requirement, Teledyne Marine suggests applying a seismic source, recently developed for the Marine Vibrator Joint Industry Project. The source is considered to be less harmful for marine inhabitants and gives more precise and higher resolution im...

The Teledyne Benthos DSP controller can stream digitized signal through standard UDP Ethernet interface to the common use customer processor. It can be Raspberry Pi with Quad Core 1.2GHz Broadcom BCM2837 64bit CPU or NVIDIA multicore Jetson with a few Gflops capability. The Raspberry Pi opens opportunity to students for quick developing new powerfu...

An infra-sound source with a resonator in the form of an underwater bubble made from an elastic material is a simple engineering solution. The elastic membrane supports high volume displacement and a large radiation aperture. The Rayleigh-Plesset equation defines the dynamics of a spherical bubble including surface tension and viscous effects. The...

The dynamics of the spherical bubble in the water defines by a Rayleigh-Plesset equation. The shape of a real bubble deforms due to gravitational effects. Its internal pressure oscillations are comparable with the difference of gravity pressure gradient and acoustic-gravity effects are part of its dynamics. The practical underwater bubble resonator...

A tunable high-Q resonator sound source with exceptional demonstrated performance has been developed by Teledyne Marine. The sound source is efficient, powerful, and has unlimited operational depth, as well as a minimum level of high frequency harmonic content. The projector transmits a digitally synthesized frequency swept signal and the mechanica...

Underwater sound scattering by a rough sea surface, ice, or a rough elastic bottom is studied. The study includes both the scattering from the rough boundary and the elastic effects in the solid layer. A coupled mode matrix is approximated by a linear function of one random perturbation parameter such as the ice-thickness or a perturbation of the s...

High-efficient tunable sound sources in the ocean and bottom tomography have 15 years of operating history. The sound source is efficient, powerful, and has unlimited operational depth, as well as a minimum level of high frequency harmonic content. The projector uses a narrow-band, highly efficient sound resonator, which is tuned to match the frequ...

The underwater sound scattering by rough seasurface,ice, or rough elastic bottom is studied. The effects of scattering from a rough elastic boundary are included in a coupled mode propagation model by the analytical equation for solid-state layer impedance. A full two-way coupled mode solution was used to derive the stochastic differential equation...

The first test of the tunable organ-pipe was successfully conducted on 11 Sept. 2001. The sound source was efficient, powerful, and had unlimited operational depth, as well as a minimum level of high frequency harmonic content. The projector uses a narrow-band, highly efficient sound resonator, which is tuned to match the frequency and phase of a r...

In November, 2001, the R/V “Point Sur” departed from the Moss Landing Marine Laboratories pier with the first prototype of a high-Q, tunable organ pipe projector. The first test of the tunable Teledyne Webb Research (TWR) organ-pipe was successfully conducted on 11.09.2001. The TWR sound source demonstrated exceptional performance. It was coherent,...

Acoustic-gravity waves (AGWs) can be generated in the ocean by mechanical energy transfer from the Earth’s crust (e.g. earthquakes or volcanoes) and by energy transfer occurring at the water surface (e.g. interaction of opposing gravity waves, ice-quakes or localized pressure changes). Recent theoretical studies shed light on the underlying physics...

Sound wave scattering caused by rough surfaces has been the subject of investigation for many decades. The problem has no exact analytic solution and approximate approaches are needed. In the ocean,scattering of sound by perturbed ocean boundaries couples acoustic modes and increases attenuation. In this paper, approximate coupled mode equations ar...

Long-range, ocean acoustic tomography, require low frequency signals covering a broad frequency band. To meet this requirement, Teledyne Webb Research has developed a system which uses a tunable, narrow-band, high-efficiency sound resonator. The projector transmits a frequency sweep signal by mechanically tuning an organ pipe to match the frequency...

As one of the participants in the Marine Vibrator JIP, Teledyne Webb Research is developing a coherent seismic marine sound source technology based on the application of an underwater, gas-filled bubble as a low frequency resonator. That innovative system is a promising candidate for a very high power, high efficiency, and coherent seismic source....

Marine Vibrators are a coherent type of sound source, which can be quieter and less harmful for marine habitants than traditional air-gun technology. Such source gives clearer, more precise and higher resolution imaging of the bottom properties due to the coherent signal and streamer array processing. Teledyne Marine Systems is developing a coheren...

The reduction of information capacity of the ocean sound channel due to scattering by internal waves is a potential problem for acoustic communication, navigation, and remote sensing over long ranges. In spite of recent progress in research on acoustic signal scattering by random internal waves and the fact that random internal waves are ubiquitous...

The dramatic reduction of sea ice in the Arctic Ocean will increase human activities in the coming years. This activity will be driven by increased demand for energy and the marine resources of an Arctic Ocean accessible to ships. Oil and gas exploration, fisheries, mineral extraction, marine transportation, research and development, tourism, and s...

Impulsive noise exists in many underwater acoustic communication environments, while traditional receivers often model it as an additive white Gaussian noise (AWGN). In a previous work, we proposed per-survivor processing (PSP) based receivers for direct sequence spread spectrum (DSSS) systems. In this work, we investigate two algorithms, passband...

Inevitably, underwater oil exploration results in underwater noise. Exploration surveys often last for months and the noise produced is becoming pervasive in the ocean. Although more research is needed to better understand the impacts of anthropogenic sound on marine biodiversity, a variety of marine flora and fauna have exhibited negative response...

The systems described include a light-weight, low frequency (200 Hz-1000 Hz), broadband underwater sound sources that comprise an inner resonator tube with thin walls tuned to a certain frequency surrounded by a shorter, larger-diameter, lower frequency tuned outer resonator tube that has an acoustic source suspended off-center inside the inner res...

A sound source includes a bubble configured to be filled with a gas. The sound source also includes an actuator configured to perturb the gas within the bubble by changing the volume of the gas without adding gas to or removing gas from the bubble. The sound source also includes a processing circuit configured to provide a control signal to the act...

Unmanned “gliders” have demonstrated long endurance operations and are the platform of choice for broad scale meteorology and oceanography (METOC). With buoyancy engines, gliders can operate for months and have demonstrated success with common oceanographic sensors. Likewise low frequency acoustics have been used for basin scale tomography for many...

Initial results of experiments performed under Arctic ice have shown that acoustic communications and navigation can be performed on scales of 10-100 km using relatively inexpensive and compact hardware. Measurements of the impulse response at ranges of 10 and 75 km reveal extensive scatter and both resolvable and unresolvable rays. Phase coherent...

Stochastic internal wave field appears to be one of the important factors in long-range sound propagation. Estimation of information capacity reduction for the underwater sound channel due to scattering of sound by internal waves is a potential problem for acoustic communications, navigation and remote sensing overlong ranges. In spite of recent pr...

In this paper, we propose a receiver of OFDM signals in fast-varying multipath underwater acoustic channels with Doppler spread covering several subcarrier intervals. The OFDM signals are cyclic-prefix-free and the transmitted and pilot data are superimposed. The data symbols are encoded across subcarriers to exploit the frequency diversity. The re...

A sound source includes a bubble configured to be filled with a gas. The sound source also includes an actuator configured to perturb the gas within the bubble by changing the volume of the gas without adding gas to or removing gas from the bubble. The sound source also includes a processing circuit configured to provide a control signal to the act...

The systems described include a light-weight, low frequency (200 Hz-1000 Hz), broadband underwater sound sources that comprise an inner resonator tube with thin walls tuned to a certain frequency surrounded by a shorter, larger-diameter, lower frequency tuned outer resonator tube that has an acoustic source suspended off-center inside the inner res...

A sound source includes a tubular resonator configured to be filled with a gas. The exterior of the resonator includes rigid and elastomeric portions. The interior of the resonator includes a first volume and a second volume. The volumes are separated by a rigid tubular wall containing at least one orifice. The at least one orifice enables a flow o...

Unmanned "gliders" have demonstrated long endurance operations and are the platform of choice for broad scale meteorology and oceanography (METOC). With buoyancy engines gliders can operate for months and have demonstrated success with common oceanographic sensors. Likewise, low frequency acoustics have been used for basin scale tomography for many...

An innovative integrated observing and model system is under development to contribute to sustainable environmental monitoring in the Arctic, and in particular to improve the estimates of heat, mass and freshwater transfer through the Fram Strait. The ice-ocean model, multipurpose acoustic system, and the oceanographic components are described, inc...

Operational monitoring and forecasting system for global and regional oceans, including the Arctic, combines observations from different satellite remote sensing techniques and in-situ open ocean measurements with ocean circulation models through advanced assimilation techniques. Satellites can sufficiently monitor changes in surface properties of...

For the first time, a multipurpose acoustic system has been deployed in a Marginal Ice Zone (MIZ) to serve acoustic tomography, navigation of gliders, tracking of floats and passive acoustics. A triangle of acoustic transceivers and a vertical receiver array in the centre were deployed in Fram Strait during summer 2010 and will be recovered in 2012...

A sound source comprises a bubble configured to be filled with a gas, an actuator configured to perturb the gas within the bubble, and a processing circuit configured to provide a control signal to the actuator to cause the actuator to perturb the gas within the bubble at a frequency defined by the control signal.

Acoustical array data from the 2006 Shallow Water Experiment (SW06) was analyzed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate received signal energy in a small number of independent channels. The data were collected by a vertical array, which spans the...

The current state-of-the-art in high-rate acoustic communications is represented by adaptive multi-channel equalization of single-carrier wideband signals. An alternative technique with significant potential for achieving high bit rates over multipath-distorted (frequency selective) channels is multi-carrier modulation (MCM). There are obvious tech...

The current state-of-the-art in high-rate acoustic communications is represented by adaptive multi-channel equalization of single-carrier wideband signals, which is used in real-time acoustic modems and as a benchmark for coherent communications performance. An alternative technique with significant potential for achieving high bit rates over multi...

Mode filtering is most commonly implemented using the sampled mode shapes or pseudoinverse algorithms. Buck et al. [J. Acoust. Soc. Am. 103, 1813-1824 (1998)] placed these techniques in the context of a broader maximum a posteriori (MAP) framework. However, the MAP algorithm requires that the signal and noise statistics be known a priori. Adaptive...

1. ABSTRACT Multi-carrier modulation (MCM) has a significant potential for achieving high bit rates over multipath-distorted (frequency selective) channels and provides both power and processing efficiency. Each frequency channel has relatively low delay spread when measured in symbol units and can be equalized with low-complexity algorithms and si...

Exploration and mapping of the Arctic Ocean by gliders and propelled autonomous underwater vehicles is hampered by ice cover and the lack of satellite navigation and communication. While acoustics offers a solution, there are many challenges to overcome. The goal of our recently-started program is to develop a system that is light enough to fit on...

In this paper Creamer's [(1996). J. Acoust. Soc. Am. 99, 2825-2838] transport equation for the mode amplitude coherence matrix resulting from coupled mode propagation through random fields of internal waves is examined in more detail. It is shown that the mode energy equations are approximately independent of the cross mode coherences, and that cro...

Mode filtering is most commonly implemented using the sampled mode shapes or pseudo‐inverse algorithms. [Buck et al. (1998)] placed these techniques in the context of a broader maximum a posteriori (MAP) framework. However, the MAP algorithm requires that the signal and noise statistics be known a priori. Adaptive array processing algorithms are ca...

Sound waves propagating in the ocean are scattered by internal waves (IWs) and spice. A modal approach for studies of low‐frequency, long‐range sound propagation in a fluctuating ocean seems to be the most adequate. This approach has been employed in a number of works, including recently published papers [A. G. Voronovich and V. E. Ostashev, J. Aco...

Operational monitoring and forecasting system for global and regional oceans, including the Arctic, combines observations from different satellite remote sensing techniques and in-situ open ocean measurements with ocean circulation models through advanced assimilation techniques. Satellites can sufficiently monitor changes in surface properties of...

In shallow water environments there is presently an incomplete understanding of the relative acoustical importance of the random linear internal-wave field compared to nonlinear internal waves packets. Using the random coupled mode theory of [Creamer (1996)], the nonlinear internal wave mode coupling theory of [Colosi (2007)], and Monte Carlo numer...

The seminal papers of Dozier and Tappert (1978), Dozier (1983), and Creamer (1996) have analyzed mode coupling induced by a random ocean sound speed structure to derive transport equations for the range evolution of mean mode energy. A major assumption in this work is that the cross-mode coherences rapidly decay with range and can thus be ignored....

Acoustical array data from the Shallow Water Acoustics experiment was processed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate received signal energy in a small number of independent channels. The data were collected by a vertical array designed at the W...

Acoustical array data from the Shallow Water Acoustics experiment was processed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate received signal energy in a small number of independent channels. The data were collected by a vertical array designed at the W...

Acoustic receptions at a vertical line array collected during the SW06 experiment were processed to show the feasibility of broadband mode decomposition as a preprocessing method to shorten time-spread and concentrate received signal energy in a small number of independent channels. The vertical array spanned the water column from 12 m depth to the...

A highly efficient frequency-controlled sound source based on a tunable high-Q underwater acoustic resonator is described. The required spectrum width was achieved by transmitting a linear frequency-modulated signal and simultaneously tuning the resonance frequency, keeping the sound source in resonance at the instantaneous frequency of the signal...

The scattering of a weakly divergent narrow sound beam by random inhomogeneities of a fluctuating ocean is considered in the coupled-mode approximation. The random index of sound refraction is described using the Garrett-Munk internal wave spectrum. The problem is solved using the stochastic differential equations for the first-and second-order sta...

The underwater acoustic channel belongs to a class of stochastic communication channels that are frequency- and, at long range, energy-limited and doubly spread. The primary challenge in underwater communications is a very large delay and Doppler spread, which complicate the application of "optimal" methods of communication. Orthogonal Frequency Di...

The conceptual architecture of an ocean acoustic system with the dual uses of submerged platform navigation and large-scale temperature measurement has been developed, and is described here. Swept FM signals would be used to synthesize short-duration pulses. A 50-Hz bandwidth is to be used, within the frequency range of 100 to 200 Hz. The potential...

Stochastic coupled mode theory is used to study acoustical scattering of a narrow‐angle, low‐frequency acoustical beam. Random index of refraction perturbation fields are described using the Garrett‐Munk internal wave spectrum. The stochastic differential equations for the first‐ and second‐order statistical moments of the acoustical field are deri...

Author Posting. © Acoustical Society of America, 2005. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 117 (2005): 1611-1623, doi:10.1121/1.1854571. Parabolic equation numerical simulations of wav...

A high Q tunable resonator makes possible the construction of an underwater sound source with a very high efficiency. Tuning this narrow‐band resonator to match the instantaneous frequency of a reference signal enables control of sound projection over a wide spectrum width. At any given time the source has one fundamental resonant frequency equal t...

Consideration is given to the physical basis for the design of a remote control system based on the transformation of a powerful light pulse to sound at the sea surface. Such a system needs no actual sound source in the water and can even be used from aircraft. The system has evident advantages with respect to optical systems in terms of the potent...

Consideration is given to the physical basis for the design of a remote control system based on the transformation of a powerful light pulse to sound at the sea surface. Such a system needs no actual sound source in the water and can even be used from aircraft. The system has evident advantages with respect to optical systems in terms of the potent...

Long-range underwater acoustic systems, such as those used in ocean acoustic tomography, require low-frequency signals covering a broad frequency band. To meet this requirement, a novel design based on a tunable narrow-band high-efficiency sound projector has been used. The projector transmits a frequency sweep signal by mechanically tuning a reson...

Scattering by small scale ocean processes like internal waves imposes the ultimate limitations on large scale ocean acoustic remote sensing. Recent progress in utilizing ray methods to understand scattering processes in long range acoustic propagation suggest there is an exponential sensitivity to initial conditions and a rapid growth of acoustic f...

Long-range, underwater, acoustic systems require low frequency signals covering a broad frequency band. We have exploited a novel approach, using a narrowband medium-output high-efficiency resonator, which transmits a frequency sweep by mechanically tuning a resonator to match the frequency and phase of the reference signal. The design begins with...

A sound source excited through the irradiation of a water surface with a powerful laser pulse is called an optoacoustic (OA) source. This phenomenon makes possible the remote control of submerged oceanographic devices (buoys) directly from a flying vehicle equipped with a pulse laser. The principal factors are analyzed (i.e., reverberation, ambient...

The high cost of acoustic tomography is the main obstruction for wide application of these systems. The inexpensive ADCP more preferable and convenient for local current experiments. However, tomography systems have unique advantage to provide integral information about 3D fields of current velocity and temperature. The principles of low-cost small...

Autonomous bottom stations and controlled buoyancy buoys with acoustic digital systems of remote control and telemetry are considered. The experience in development and maintenance of autonomous bottom station of P.P. Shirshov Institute of Oceanology applied for the complex acoustic measurements is described. This experience resulted in manufacturi...

Estimation of the impulse response of a hydroacoustic channel with random signal Doppler frequency shifts and phase fluctuations by M-sequence phase manipulated signals is considered. The performance of phase-shift-keyed (PSK) signal processing methods is ascertained in the case of unknown or random Doppler frequency shift of the carrier. Developed...

During an international acoustic tomography experiment, which had been deployed in the western Mediterranean in 1994, acoustic measurements with vertical arrays were made from autonomous bottom modules. Due to near‐bottom signal receiving, a number of time‐separated bottom reflected and refracted signals were obtained after correlation processing....