Browsing by Title
Now showing items 631-650 of 882
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Rays and statistical diffraction theory
(NATO. SACLANTCEN, 1971/12)A method of extending ray tracing is proposed, such that mediumscale irregularities of a statistical nature are taken into account along with large-scale irregularities in refractive index of the medium. -
Real time-frequency active sonar processing: a massively parallel approach
(NATO. SACLANTCEN, 1993/08)A paradigm for massively parallel processing of matched filters, replica correlators, ambiguity functions and time-frequency distributions using an SIMD (Single Instruction Multiple Data) programming methodology is presented. ... -
Real-and synthetic-array signal processing of buried targets
(NATO. SACLANTCEN, 2002/01)Results from two field experiments aimed at investigating the detection and classification of buried targets are presented. In both experiments a 2-16 kHz parametric source was used. In the first experiment the source was ... -
Real-time clock synchronisation in underwater acoustic networks
(CMRE, 2019/06)This paper proposes an algorithm for real-time clock synchronisation in underwater acoustic networks. The algorithm models modem clocks as linear functions and embeds the data necessary for the clock synchronisation procedure ... -
Real-time continuous active sonar processing
(CMRE, 2019/06)This work describes the development of continuous active sonar (CAS) processing at CMRE. The software uses subband processing to achieve a faster update rate than is possible with pulsed active sonar (PAS). The software ... -
Real-time expanded-band beamforming using a complex heterodyner and fast array processor
(NATO. SACLANTCEN, 1979/12)At the Defense Research Establishment Atlantic Dartmouth, Nova Scotia, Canada a data aquisition sytem been engineered to monitor and beamform data from element line arrays. This system has been designed to with either towed ... -
Real-time mosaicing of large scale areas with forward looking sonar
(CMRE, 2019/06)Mosaicing of large scale areas is an important application in the field of underwater computer vision. Although most of the works use optical cameras for that purpose, Forward Looking Sonars, also called acoustic cameras, ... -
Real-time processing of acoustic and oceanographic data at sea
(NATO. SACLANTCEN, 1972/05) -
Real-time underwater positioning and navigation of an AUV in deep waters
(CMRE, 2019/05)Due to the absence of GPS, navigation of autonomous vehicles underwater requires the integration of various measurements to provide the best location estimate. Usually in littoral waters, adequate navigational accuracy may ... -
Real-time, general-purpose, high-speed signal processing systems for underwater research: proceedings of a working-level conference held at SACLANTCEN on 18-21 September 1979 - part 1 : sessions 1 to 3
(NATO. SACLANTCEN, 1979/12)During the last few years, advances in the computer field have reached a level where it is possible to implement fast signal-processing systems through the use of standard computer equipment operating in association with ... -
Realistic extended target model for track before detect in maritime surveillance
(CMRE, 2019/06)Traditional target tracking algorithms are generally fed a set of thresholded detections under the hypothesis that no more than one detection is generated by each single target. Improvements in modern radar systems have ... -
Realistic ship model for extended target tracking algorithms
(CMRE, 2019/06)Recent developments in high resolution sensors have encouraged the use of Extended Target Tracking (ETT) algorithms specifically designed to deal with targets that generate more than one detection per frame. At the same ... -
Receiving and transmitting acoustic systems for AUV/gliders
(NURC, 2009/12)NURC in the past years have focused its research on the use of AUV and more recently on gliders and is now developing littoral autonomous sensing networks based onthose sensors to perform missions such as mine warfare, ... -
Recent technological advances in underwater autonomy
(2019/05)Underwater Unmanned systems (or more precisely systems of systems) will definitely play an important role in future maritime surveillance and environmental data collection. For many years, the NATO Centre for Maritime ... -
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 ... -
Reduction of low frequency active sonar clutter through image processing
(NATO. SACLANTCEN, 1997/12)Large numbers of false clutter detections arise in the use of low frequency active sonar for the detection of low Doppler submarine targets in shallow water. Traditional detection algorithms operate individually on each ... -
Reflection of sound from a layered ocean bottom
(NATO. SACLANTCEN, 1975/10) -
Refraction of sound in the sea floor
(NATO. SACLANTCEN, 1975/10)A major mode of propagation of acoustic energy at low frequencies is a shallow refracted path through unconsolidated sediments of the sea floor. Successful modelling of the bottom-refracted mode of propagation requires ... -
Regional reflection seismic exploration of the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)A regional seismic reflection survey was performed by OGS in 1970 on the Sicily Channel, using multichannel digital techniques and flexotir source. Reflections up to about 5 s (two-way time) have been obtained. The analysis ...