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Now showing items 21-30 of 49
Maritime surveillance using multiple high-frequency surface-wave radars
(CMRE, 2014/05)
In the last decades, great interest has been directed toward low-power high-frequency (HF) surface-wave radars as long-range early warning tools in maritime-situational-awareness applications. These sensors, developed for ...
Decision tree-based adaptive modulation for underwater acoustic communications
(CMRE, 2017/11)
Underwater acoustic channels are characterised by non-stationary fading statistics and consequently, a modulation scheme optimally designed for a specific fading model will underperform when the channel statistics ...
A novel approach for a bistatic scattering calculation suitable for sonar performance model
(CMRE, 2014/01)
One of the classical approaches to the calculation of the sound pressure scattered from a rough surface is to sum the contributions to the field from a set of small tiles that approximate the surface. If the tiles are ...
Performance assessment of the MUSCLE synthetic aperture sonar
(CMRE, 2014/01)
Synthetic Aperture Sonar (SAS) systems are quickly becoming fundamental tools for seabed mapping applications, as they provide high resolution imagery independent of range from the sensor, with high area coverage rates. ...
GLider Acoustics Sensing of Sediments (GLASS): experiments and data analysis
(CMRE, 2013/12)
Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ...
Fostering the use of JANUS in operationally-relevant underwater applications
(CMRE, 2017/11)
This paper presents the use of JANUS in operationally-relevant underwater applications. JANUS is an open, simple and robust digital coding technology currently in process to become a NATO standard. Two underwater scenarios ...
Ray convergence in a flux-like propagation formulation
(CMRE, 2014/01)
The energy flux formulation of waveguide propagation is closely related to the incoherent mode sum, and its simplicity has led to development of efficient computational algorithms for reverberation and target echo strength, ...
The relation between the waveguide invariant, multipath impulse response, and ray cycles
(NURC, 2012/04)
The waveguide invariant, b, that manifests itself as interference fringes or "striations" in a plot of frequency vs source-receiver separation, is usually thought of as a modal phenomenon. This paper shows that striations ...
Redesigning the SLOCUM glider for torpedo tube launching
(NURC, 2012/04)
Launching gliders from a submarine torpedo tube is of special interest for military operations. This is not currently possible because the wing span needed to achieve a good gliding performance is twice the standard diameter ...
Automated port traffic statistics: from raw data to visualization
(CMRE, 2017/11)
We describe how we leveraged best practices in big data processing pipeline design and visual analytics to prototype the Maritime Patterns-of-Life Information Service (MPoLIS), an information product currently under ...