Browsing Reprints by Title

Now showing items 396-415 of 548

    • Receiving and transmitting acoustic systems for AUV/gliders 

      Maguer, Alain; Dymond, Rodney; Guerrini, Piero; Troiano, Luigi; Grandi, Vittorio; Figoli, Alberto; Olivero, Claudio; Sapienza, Alessandro; Fioravanti, Stefano; Potter, John Robert (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 

      Maguer, Alain; Been, Robert; Tesei, Alessandra; Alves, João; Grandi, Vittorio; Biagini, Stefano (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 

      Alvarez, Alberto (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 ...

    • Reflection of sound from a layered ocean bottom 

      Bucker, Homer P.; Morris, Halcyon E. (NATO. SACLANTCEN, 1975/10)

    • Refraction of sound in the sea floor 

      Christensen, R. E.; Geddes, W. H. (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 

      Finetti, I.; Morelli, Carlo (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 ...

    • Relating in situ shear wave velocity to void ratio and grain size for unconsolidated marine sediments 

      Huws, Dei; Davis, Angela; Pyrah, James (NATO. SACLANTCEN, 1997)
      Recent advances in field hardware have meant that it has become possible to measurein situ shear wave velocity in the upper few decimetres of sea floor sediment in a routine manner. It is known that shear wave velocity can ...

    • Relative contribution of surface roughness and bottom attenuation to propagation loss in shallow water 

      Kuperman, William A.; Ingenito, Frank (NATO. SACLANTCEN, 1975/10)
      A simulation study has been performed to investigate the relative importance of the contributions of surface roughness and bottom attenuation to propagation loss under differing environmental conditionso The NRL normal ...

    • A relocatable EnKF ocean data assimilation tool for heterogeneous observational networks 

      Falchetti, Silvia; Alvarez, Alberto; Onken, Reiner (CMRE, 2019/06)
      This study investigates the performance of a multivariate Ensemble Kalman Filter coupled with a relocatable limited-area configuration of the Regional Ocean Modeling System to predict ocean states by assimilating a ...

    • Results from the use of broad-band, sub-bottom seismic data with statistically based sediment classification techniques 

      Simpkin, Peter G.; Collins, William T. (NATO. SACLANTCEN, 1997)
      The QTC VIEW sediment classification system has been applied to shallow, high resolution seismic data recorded with the IKB-SEISTEC profiler from the navigable channel of the St. Lawrence estuary in Canada. A number of 10 ...

    • Retrodirective array performance case studies and implications for mine countermeasures 

      Hallaj, I. M.; Kargl, Steven G.; Roy, R. A. (NATO. SACLANTCEN, 1997)
      The use of focused acoustic fields for the mechanical destruction of fluid-borne targets is applied zn. the medical field for the comminution of kidney stones by lithotripsy. Inhomogeneities in the propagation medzum are ...

    • Review of numerical models in underwater acoustics including recently developed fast-field program 

      Jensen, Finn B.; Schmidt, Henrik (NATO. SACLANTCEN, 1984/12)
      Two papers given by SACLANTCEN personnel at the NATO Advanced Research Workshop on Hybrid Formulation of Wave Propagation and Scattering at Castel Gandolfo, Rome, Italy on 30 August to 3 September 1983 are published as a ...

    • Review of target strength information for waterside security applications 

      Zampolli, Mario; Jensen, Finn B.; Tesei, Alessandra (NURC, 2008)
      Estimates of the target strength of objects, such as for example scuba tanks and swimmer delivery vehicles, are parameters of interest in all phases of the design of waterside security systems. Results of numerical target ...

    • Riverine environmental acoustics at an ocean estuary 

      Muir, Tom G.; Blue, J. E.; Anderson, A. L. (NATO. SACLANTCEN, 1997)
      The purpose of these studies was to investigate some of the more important geoacoustrc parameters that might govern the use of high frequency sonar in muddy rivers, where they flow into the sea. Both environmental and ...

    • A robust, opportunistic clock synchronization algorithm for ad hoc underwater acoustic networks 

      Vermeij, Arjan; Munafò, Andrea (CMRE, 2019/06)
      The proliferation of deployed sea-going autonomous platforms, such as autonomous underwater vehicles (AUVs), unmanned surface vehicles (USV), and sensor nodes anchored to the seabed, makes the deployment of true underwater ...

    • Role of propagation in ambient noise 

      Ross, Donald (NATO. SACLANTCEN, 1982/06)
      To be useful for modern ASW systems design and analyses, descriptions of ambient noise fields must go beyond average omnidirectional spectra and include horizontal and vertical patterns, fluctuations with time, dependencies ...

    • SACLANTCEN real-time signal processing system 

      Seynaeve, Robert; Boni, Pier Angiolo; Duarte, Vasco; McCann, Michael J.; Nesfield, Philip (NATO. SACLANTCEN, 1979/12)
      To meet its increasing requirements in real-time signal processing, SACLANTCEN has developed a general purpose. signal processing system called WARP to be uS.ed with a fairly wide range of underwater acoustic research ...

    • Scalable adaptive multitarget tracking using multiple sensors 

      Meyer, Florian; Braca, Paolo; Hlawatsch, Franz; Micheli, Michele; LePage, Kevin D. (CMRE, 2019/06)
      In networked mobile multitarget tracking systems, parameters such as detection probabilities, clutter rates, and motion model parameters are often unknown and time-varying. Such parameter variability can seriously degrade ...

    • A scalable algorithm for tracking an unknown number of targets using multiple sensors 

      Meyer, Florian; Braca, Paolo; Willett, Peter K.; Hlawatsch, Franz (CMRE, 2019/06)
      We propose an algorithm for tracking an unknown number of targets based on measurements provided by multiple sensors. Our algorithm achieves low computational complexity and excellent scalability by running belief propagation ...

    • Scalable and distributed sea port operational areas estimation from AIS data 

      Millefiori, Leonardo; Zissis, Dimitrios; Cazzanti, Luca; Arcieri, Gianfranco (CMRE, 2019/06)
      Seaports are spatial units that do not remain static over time. They are constantly in flux, evolving according to environmental and connectivity patterns both in size and operational capacity. As such any valid decision ...