Browsing Reprints by Type "Conference Proceedings (CP)"

Now showing items 181-200 of 290

    • Overview of the ADPS signal processor 

      Pennoyer, Bryson (NATO. SACLANTCEN, 1979/12)

    • Performance assessment of broadband impulsive noise jammers 

      Heine, J.; Theriault, Kenneth B.; Boseck, D. (NATO. SACLANTCEN, 1993/08)
      A noise jammer raises the noise level observed by a threat sonar to degrade the sonar's detection performance. In this paper we assess the potential for a specific noise jammer waveform used to countermeasure low frequency ...

    • Performance of three averaging methods for various distributions 

      Nuttall, Albert H. (NATO. SACLANTCEN, 1982/06)
      The performance of three averaging methods, namely the sample median, the sample arithmetic mean, and the sample geometric mean, are analyzed in tenns of their bias, variance, and mean square error. The bias and variance ...

    • Physics of bottom scattering and some applications 

      Gensane, Marc (NATO. SACLANTCEN, 1997)
      The main bottom scattering theories are described in their bistatic formulation: composite-roughness, and volume scattering. Several applications are proposed. One of the main concerns is to check the mono- and bisfafic ...

    • Position and shape of the surface shadow zone 

      De Raigniac, Bernard (NATO. SACLANTCEN, 1971/12)
      From surface reverberation studies conducted by SACLANTCEN's Target Classification Group"C , it has been found necessary to know before any sea experiment the precise position of the first surface shadow zone. Since normal ...

    • Practical active sonar receiver systems using fast frequency-domain correlation 

      Curtis, T. E.; Webb, A. B. (NATO. SACLANTCEN, 1993/08)

    • Preliminary results of current measurements in the Strait of Sicily in May 1970 

      Molcard, Robert (NATO. SACLANTCEN, 1972/09)
      During May 1970, series of oceanographic observations were made in the Strait of Sicily in support of MILOCMED. Sections of hydrologic stations were made using temperature salinity recorder (TDS) and Nansen bottles by R/ ...

    • Processing of broadband acoustic signals 

      Hovem, Jens M. (NATO. SACLANTCEN, 1972/05)

    • Propeller leading edge trimming and maintenance effects on ship's noise operational performance 

      Accardo, Lucio; Baù, F. (NATO. SACLANTCEN, 1985/01)
      In the last ten years, considerable experience has been gathered at CEIMM's cavitation tunnel (Centra Esperienze Idrodinamiche Marina Militare) on the effects of propeller leading edge geometry on cavitation (and noise) ...

    • 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-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 ...

    • 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-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 processing of acoustic and oceanographic data at sea 

      Martin, Robert L. (NATO. SACLANTCEN, 1972/05)

    • 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 ...