Now showing items 620-639 of 882

    • Qualitative aspects of seismograph-ocean bottom interaction 

      Snoek, Michael; Herber, R. (NATO. SACLANTCEN, 1988/06)
      The parameters affecting the coupling of the Ocean Bottom Seismometer to the ground have been
    • RABEL - A program to replay ABEL version 2.2 

      Canepa, Gaetano (NATO. SACLANTCEN, 1997/05)
      The description of a graphics software tool used to view and manipulate data file is presented. The software is implemented to run in the IDL environment on any platform. RAbel is able to read data from files in the ADAM ...
    • Random temperature structure as a factor in long-range propagation 

      Del Balzo, Donald R.; Moseley, W. B. (NATO. SACLANTCEN, 1975/10)
      A statistical description of horizontal thermal microstructure in anosotropic turbulence is developed for application with an existing acoustic propagation theory. The model predicts a temperature power density spectrum ...
    • Range and depth estimation by line arrays in shallow water 

      Klemm, Richard (NATO. SACLANTCEN, 1982/01)
      In shallow water sound propagates in terms of normal modes. The interference between the modes can be utilized to estimate range and depth of an acoustic source in shallow water by applying high resolution power estimators ...
    • Range estimation of cetaceans with compact volumetric arrays 

      Zimmer, Walter M. X. (CMRE, 2014/01)
      Passive acoustic monitoring is the method of choice to detect whales and dolphins that are acoustically active and to monitor their underwater behaviour. The NATO Science and Technology Organization Centre for Maritime ...
    • Range-dependent normal modes in underwater sound propagation 

      Graves, Ronald D.; Nagl, Anton; Uberall, Herbert M.; Haug, Anton J.; Zarur, George L. (NATO. SACLANTCEN, 1975/10)
      Normal mode theory is best suited for the case of stratified media. Range dependence of the medium properties and of its boundary may nevertheless be taken into account in the framework of an adiabatic approximation provided ...
    • Rapid Environmental Assessment: Proceedings of a conference held in Lerici, Italy, 10-14 March 1997, organized and sponsored by NATO SACLANTCEN 

      Rapid Environmental Assessment Conference (1997 March 10-14 : Lerici, Italy) (NATO. SACLANTCEN, 1997)
    • RAPID RESPONSE, september 1996: modelling of broadband transmission loss along selected tracks in the Strait of Sicily 

      Ferla, Carlo M.; Jensen, Finn B.; Akal, Tuncay (NATO. SACLANTCEN, 1997/07)
      A large set of experimental acoustic broadband data in the 50-3200 Hz band is analyzed with the objective of deriving average geoacoustic models for three sites in the Strait of Sicily. The experimental data were obtained ...
    • Ray convergence in a flux-like propagation formulation 

      Harrison, Chris H. (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, ...
    • Ray tracing on a mini-computer 

      Thompson, Martin; Wijmans, Willem (NATO. SACLANTCEN, 1971/12)
      It would appear that most people engaged in solving problems in ray- tracing, use programs written for large computers . These machines commonly have large memory sizes, fast cycle times and large word length 0 This paper ...
    • Ray tracing on a mini-computer 

      Thompson, Martin; Wijmans, Willem (NATO. SACLANTCEN, 1972/05)
      It would appear that most people engaged in solving problems in ray- tracing, use programs written for large computers. These machines commonly have large memory si~es, fast cycle times and large word length . This paper ...
    • Rays and statistical diffraction theory 

      Clarke, Richard H. (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 

      Zvara, George P. (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 

      Pinto, Marc A.; Bellettini, Andrea; Hollett, Reginald D.; Tesei, Alessandra (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 

      Vermeij, Arjan; Munafò, Andrea (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 

      Canepa, Gaetano; Munafò, Andrea; Murphy, Brian; Micheli, Michele; Morlando, Luca (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 

      Crowe, D. Vance (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 

      Ferreira, Fausto; Djapic, Vladimir; Caccia, Massimo (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 

      Martin, Robert L. (NATO. SACLANTCEN, 1972/05)
    • Real-time underwater positioning and navigation of an AUV in deep waters 

      Tesei, Alessandra; Micheli, Michele; Vermeij, Arjan; Ferri, Gabriele; Mazzi, Marco; Grenon, Gabriel; Morlando, Luca; Biagini, Stefano; LePage, Kevin D.; Costanzi, Riccardo; Fenucci, Davide; Caiti, Andrea; Munafò, Andrea (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 ...