Browsing Reprints by Subject "Modelling and simulation"

Now showing items 1-13 of 13

    • Analysis and problems of HF acoustic coherent and incoherent simulations in shallow water 

      Thomson, Pat; Bell, Judith (NATO. SACLANTCEN, 1997)
      Shallow water environments create complex scattering condit~ons due to the sea surface and bottom scattering mechanisms. An analysis of the effects of the scattering mechan~smso n sonar images of simple targets in shallow ...

    • Array and cable tracking data through ship maneuvers 

      Toplosky, N. (NATO. SACLANTCEN, 1993/08)
      This paper presents tracking results from two sea tests in which a towed cable and array were tracked at the Atlantic Undersea Test and Evaluation Center (AUTEC). The tracking tests involved instrumenting the cable with ...

    • Array shape determination with a real-time model 

      Ruffa, A. A. (NATO. SACLANTCEN, 1993/08)
      A shape estimation scheme based on precomputed frequency-domain solutions of array motion is presented. The boundary conditions supporting each solution are discrete Fourier transform (OFT) components of sensor measurements, ...

    • Counter piracy surveillance requirements for early detection, military rescue, or evasion 

      Kessel, Ronald T.; De Rosa, Francesca (NURC, 2012/06)
      Best practice for protection against pirates includes coordination with the military forces operating in the area, constant watch against the approach of pirates, and measures to prevent or delay their boarding. The time ...

    • Detection models and target information processing 

      Bond, James W. (NATO. SACLANTCEN, 1982/06)
      The passive sonar equation leads in a natural manner to sensor detection performance contours. Useful information can be extracted from observed fractional holding time on non-cooperative targets by use of these contours. ...

    • High-resolution characterization of seafloor sediments for modeling acoustic backscatter 

      Orsi, Thomas H.; Duncan, Michael E.; Lyons, Anthony P.; Briggs, Kevin B.; Richardson, Michael D.; Anderson, Aubrey L. (NATO. SACLANTCEN, 1997)
      Quantitative information on fine-scale sediment inhomogeneity is extremely scarce and sorely needed for developing realistic volume scattering models. To address this deficiency, we present a novel approach for sediment ...

    • HLA interoperability for ROS-based autonomous systems 

      Carrera, Arnau; Tremori, Alberto; Caamaño Sobrino, Pilar; Been, Robert; Crespo Pereira, Diego; Bruzzone, Agostino (CMRE, 2019/06)
      The requirements for autonomous systems (of systems) have started to include the cooperation between heterogeneous assets in order to accomplish complex missions. Therefore, interoperability - both at the conceptual and ...

    • Low frequency active sonar (LFA) bottom loss requirements 

      Jensen, Edmond P.; Sabbadini, Fernando (NATO. SACLANTCEN, 1993/08)
      A bottom interaction simulator was developed to investigate LFA bottom bounce losses, i.e., the mismatch losses, which occur in matched filter processing of bottom and target reflected signals due to the time spreading ...

    • Modeling of subcritical penetration into sediments due to interface roughness 

      Thorsos, Eric I.; Jackson, Darrell R.; Moe, John E.; Wiliams, Kevin L. (NATO. SACLANTCEN, 1997)
      Recent experimental results reveal acoustic penetration into sandy sediments at grazing angles below the critical angle. We have been investigating a mechanism for subcritical penetration based on scattering at a rough ...

    • 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 ...

    • 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 ...

    • Shallow-water coherence of broadband signals 

      Badiey, Mohsen; Simmen, J.; Tang, X. (NATO. SACLANTCEN, 1997)
      The frequency-dependent spatial and temporal variabilities of sound propagation in coastal regions is investigated by ezperiment and numerical simulations. Experimental observations show that temporal coherence of the ...

    • The Response model: an operational model for towed array shape and attitude estimation validated on TABAT data 

      Van Aartsen, C. S. (NATO. SACLANTCEN, 1993/08)
      An operational model for array shape and attitude estimation, based on the continuous measurement of heading and depth at a single position in the array, is presented. This model, which we call the Response model has been ...