Browsing Reprints by Title

Now showing items 322-341 of 548

    • Multipath pulse shape in a refracting environment 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/11)
      Multiple boundary interactions in shallow water propagation introduce a more or less Gaussian angle distribution at a distant receiver. When all paths are added the result is 'mode-stripping', i.e. the steep rays are ...

    • Multipath pulse shapes in shallow water: theory and simulation 

      Harrison, Chris H.; Nielsen, Peter L. (NURC, 2007/04)
      In shallow water propagation the steeper ray angles are weakened most by boundary losses. Regarding the sound intensity as a continuous function of angle it can be converted into a function of travel time to reveal the ...

    • Multiple Bayesian extended target tracking 

      Vivone, Gemine; Braca, Paolo; Granström, Karl; Willett, Peter K. (CMRE, 2019/06)
      To track an extended target presents challenges because the hypothesis of "one target means one detection" is not valid. Several approaches to extended target tracking (ETT) have been found promising, and in particular ...

    • Multiple Ornstein-Uhlenbeck processes for maritime traffic graph representation 

      Coscia, Pasquale; Braca, Paolo; Millefiori, Leonardo; Palmieri, Francesco A. N.; Willett, Peter K. (CMRE, 2019/05)
      We propose an unsupervised procedure to automatically extract a graph-based model of commercial maritime traffic routes from historical Automatic Identification System (AIS) data. In the proposed representation, the main ...

    • Multiple sensor Bayesian extended target tracking fusion approaches using random matrices 

      Vivone, Gemine; Granström, Karl; Braca, Paolo; Willett, Peter K. (CMRE, 2019/06)
      The tracking of extended targets is attracting a growing literature thanks to the high resolution of several modern radar systems. A fully Bayesian solution has been proposed in the random matrix framework. In this paper, ...

    • Multiple sensor measurement updates for the extended target tracking random matrix model 

      Vivone, Gemine; Granström, Karl; Braca, Paolo; Willett, Peter K. (CMRE, 2019/06)
      In this paper, multiple sensor measurement update is studied for a random matrix model. Four different updates are presented and evaluated: three updates based on parametric approximations of the extended target state ...

    • Multisensor adaptive Bayesian tracking under time-varying target detection probability 

      Papa, Giuseppe; Braca, Paolo; Horn, Steven A.; Marano, Stefano; Matta, Vincenzo; Willett, Peter K. (CMRE, 2019/06)
      In practical tracking applications, the target detection performance may be unknown and also change rapidly in time. This work considers a network of sensors and develops a target-tracking procedure able to adapt and react ...

    • Multistatic bottom reverberation in shallow water 

      Schmidt, Henrik; Lee, Jaiyong; Fan, Huaiyu; LePage, Kevin D. (NATO. SACLANTCEN, 1997)
      A wavenumber integration approach to modeling of the full multistatic reverberant field produced by small-scale bottom roughness in stratified shallow water waveguides has been developed. A perturbation approach to rough ...

    • Multistatic sonar: a road to a maritime network enabled capability 

      Been, Robert; Jespers, Stephane; Coraluppi, Stefano; Carthel, Craig; Strode, Christopher; Vermeij, Arjan (NURC, 2007/10)
      NATO's operational requirements emphasize interoperability of platforms participating in coalition task forces. Intelligently fusing data of multiple sensor systems and the development of adapted tactics are necessary steps ...

    • Mutual coherence and silence 

      Debart, Hubert P. (NATO. SACLANTCEN, 1985/01)
      In this paper we are developing the theoretical principle of a modification of the acoustical emission by a ship. Its objective is making inefficient the angular measurements achieved by a detector. More precisely, the ...

    • Near field propeller radiated noise measurements: model and full scale experimental data comparison 

      Accardo, Lucio; Colombo, Agostino (NATO. SACLANTCEN, 1985/01)
      The ever rising interest related to the underwater no1se originating from cavitating propellers prompted the Italian Navy to study this aspect of naval architecture in an experimental way. This was accomplished carrying ...

    • NEMO: An architecture for software communications research in the maritime domain 

      Vermeij, Arjan; Furfaro, Thomas C.; Alves, João (CMRE, 2019/06)
      This paper presents a high-level overview of NEMO, an implementation of a communications research software workspace with special focus on application scenarios involving underwater (e.g. acoustic), and other maritime ...

    • Network-enabled information fusion in support of underwater research 

      Berni, Alessandro; Merani, Diego; Leonard, Michel (NURC, 2007/11)
      Advanced communication and information processing techniques can be applied to underwater research to enable new ways of enhancing real-time experimental outcome. This paper is concerned with three main areas where ...

    • The new muesli complexity metric for mine-hunting difficulty in sonar images 

      Williams, David P. (CMRE, 2019/05)
      A new image complexity metric has been developed that fuses the concept of lacunarity, a measure of pixel intensity variation, with the notion of spatial information, a quantity that captures edge energy. This new metric, ...

    • Noise sources in the ocean - part 1 

      Wille, Peter C. (NATO. SACLANTCEN, 1975/10)
      Following a brief historical survey of the development of our knowledge of the origins and characteristics of ambient noise in the ocean, the principal known sources of noise are described. These are: environmental origin, ...

    • Noise sources in the ocean - part 2 

      Daintith, Maurice J. (NATO. SACLANTCEN, 1975/10)
      Following a brief historical survey of the development of our knowledge of the origins and characteristics of ambient noise in the ocean, the principal known sources of noise are described. These are: environmental origin, ...

    • NOSC signal processing evaluation laboratory 

      Pennoyer, Bryson (NATO. SACLANTCEN, 1979/12)
      A new acoustic Signal Processing Evaluation Laboratory (SPEL) at the Naval Ocean Systems Center (NOSC), San Diego, is described. This laboratory has been designed to support a broad program of research and development of ...

    • Notes on the interpretation of ambient noise statistics 

      Cavanagh, Raymond C. (NATO. SACLANTCEN, 1982/06)
      Interpretation of statements about the character of ambient sea noise, as well as schemes to measure or model noise, are sensitive to the context or underlying view of what is essentially a stochastic process. A framework ...

    • Numerical modeling results for mode propagation in a wedge 

      Jensen, Finn B.; Tindle, C. T. (NATO. SACLANTCEN, 1987/11)
      A PE (parabolic equation) code is used to study propagation in a shallow water wedge with a penetrable bottom. Particular attention is given to "wedge modes" that have wave fronts that are arcs of circles centered on the ...

    • Numerical modelling of acoustic scattering by smooth inclusions in a layered fluid-solid medium 

      Karasalo, Ilkka; Mattsson, Johan (NATO. SACLANTCEN, 1997)
      A boundary integral equation (BIE) method as descnbed for computing the scattering of a monofrequent acoustic field by a smooth, rigid 30 object in a layered range-independent fluid-solid medium. The BIE is discretized ...