Browsing CMRE Publications by Subject "Signal processing"

Now showing items 41-60 of 118

    • Effect of different bandwidths for the detection of extended targets in reverberation 

      Ries, S.; Schmidt-Schierhorn, H. (NATO. SACLANTCEN, 1993/08)
      In this paper, firstly the theoretical background of bandwidth effects on detection in noise and reverberation is presented in some detail, and secondly the relevant results of sea. trials with a low frequency active sonar ...

    • EM phenomena in the ELF range: natural background noise and instrumentation for its measurement 

      Brock-Nannestad, Lars (NATO. SACLANTCEN, 1965/06)
      The report is the second of a series of three that discusses various EM phenomena in the ELF range. A general outline of the natural background noise in the frequency range between 1 and 50 cps is given and the measurement ...

    • Estimation of chirp sonar signal attenuation for classification of marine sediments: improved spectral ratio method 

      Maroni, C. S.; Quinquis, A. (NATO. SACLANTCEN, 1997)
      Remote sediment classification through acoustic methods is of great interest for a few years. The attenuation coefficient of the transmitted wave is an important feature to characterize physical sediment layers properties. ...

    • Estimators for model-based passive localization 

      Sullivan, Edward J.; Volkmann, W. M.; Bongi, Silvio (NATO. SACLANTCEN, 1988/07)
      A comparative study is made of the performance of four different estimators as used in the matched field technique of passive localization. The study is based on both real and synthesized data. In the synthesized data case, ...

    • Experience with a MAP 300 array processor 

      Nesfield, Philip (NATO. SACLANTCEN, 1979/12)
      The paper is a summary of the experience collected during almost two years of programming a CSPI MAP 300 array ' processor in signal processing applications. After a short overview of the most interesting features of SNAP ...

    • Extended target tracking applied to X-band radar data 

      Vivone, Gemine; Braca, Paolo; Errasti, Borja (CMRE, 2019/06)
      X-band marine radar systems are flexible and low-cost tools for monitoring multiple targets in a surveillance area. They are able to provide high resolution measurements in both space and time. Such features offer the ...

    • Extended target tracking using joint probabilistic data association filter on X-band radar data 

      Vivone, Gemine; Braca, Paolo; Errasti, Borja (CMRE, 2019/06)
      X-band Marine radar systems are low-cost tools for monitoring multiple targets in a surveillance area. Although they may suffer from several sources of interference, high resolution measurements in both space and time can ...

    • Extended towed-array processor by overlapped correlator 

      Stergiopoulos, S.; Sullivan, Edward J. (NATO. SACLANTCEN, 1988/11)
      The development of an algorithm for extended towed-array measurements, which could be used by matched-field estimators to obtain information about depth and range of a source, is studied. This algorithm combines coherently ...

    • Formulae for bistatic signal and reverberation 

      Harrison, Chris H. (NATO. SACLANTCEN, 2002/12)
      This report demonstrates that it is possible to obtain closed-form solutions for signal and reverberation in a wide variety of bistatic scenarios including ducts and bottom bathymetry. These formulae adapt earlier monostatic ...

    • Frequency deviation indicator 

      Rynja, Henk A. J. (NATO. SACLANTCEN, 1963/11)
      A new type of discriminator was developed to measure the frequency variation of electrical signals; it has the special feature to indicate without any delay the difference between the signal frequency and some fixed reference ...

    • Graphics for real-time signal-processing systems 

      McCann, Michael J. (NATO. SACLANTCEN, 1979/12)
      A graphics software package able to produce hardcopy plots of multi-channel (of the order of 100 channels) data for real-time applications is described. The system is implemented at present using a lineprinter with graphics ...

    • High resolution feature extraction from reverberation data 

      MacLeod, Robert B.; Tufts, Donald W. (NATO. SACLANTCEN, 1997)
      A new method of signal approximatzon is presented which has the capability to model complex active returns due to reverberation. The method explored herein is data adaptive in the sense that high resolution processing is ...

    • High-resolution analysis of non-stationary data ensembles 

      Klemm, Richard (NATO. SACLANTCEN, 1980/10)
      Estimation of an unknown parameter of a random data ensemble is usually done by maximizing a certain power estimator by varying the unknown parameter. This method is convenient where the data are a nonlinear function of ...

    • Impact of uncertain environmental knowledge on the shallow-water transfer function 

      Gingras, Donald F. (NATO. SACLANTCEN, 1992/12)
      It is assumed that the acoustic channel can be modeled as a linear time-invariant space-variant filter. In this case, from linear systems theory, it is known that the filter output, that is the predicted source signal ...

    • Incoherent sub-band averaging for improved target detection and Doppler estimation in linearly frequency modulated continuous active sonar 

      Bates, Jeffrey; Grimmett, Douglas; Canepa, Gaetano; Tesei, Alessandra (CMRE, 2019/05)
      Linear frequency modulated (LFM) continuous active sonar (CAS) waveforms show promise for use in target tracking given that waveforms can be split into sub-waveforms (sub-bands), thereby increasing the target refresh rate. ...

    • Influence of background-noise spatial coherence on high-resolution passive method 

      Bienvenu, Georges; Kopp, Laurent (NATO. SACLANTCEN, 1982/06)
      New signal processing methods for passive listening have appeared recently : they are called "high resolution" methods because they have theoretically a better resolving power than conventional or adaptive beamforming . ...

    • Joint probabilistic data association tracker for extended target tracking applied to X-band marine radar data 

      Vivone, Gemine; Braca, Paolo (CMRE, 2017/11)
      X-band marine radar systems are flexible and low-cost tools for monitoring multiple targets in a surveillance area. Although they may suffer from several sources of interference, e.g., sea clutter, they can provide ...

    • Knowledge-based ship tracking applied to HF surface wave radar data 

      Vivone, Gemine; Horstmann, Jochen; Braca, Paolo (CMRE, 2019/06)
      In recent years, low-power high-frequency surface-wave radars have received significant attention thanks to their over-the-horizon coverage capability and the continuous-time operation mode. These radars have become effective ...

    • Knowledge-based ship tracking applied to HF surface wave radar data 

      Vivone, Gemine; Braca, Paolo; Horstmann, Jochen (CMRE, 2019/06)
      In recent years, low-power high-frequency surface-wave radars have received significant attention thanks to their over-the-horizon coverage capability and the continuous-time operation mode. These radars have become effective ...

    • Laboratory utilization of a standard signal processor 

      Molino, Frank W.; Vernaglia, John E.; Lambs, Jerry C.; Coggins, William J. (NATO. SACLANTCEN, 1979/12)
      The AN/UYS-l Advanced Signal Processor (ASP), or PROTEUS, is the U.S. Navy's standard signal processor and is being utilized in several systems. For shipboard use, the ASP is used as a processor with no peripherals, generally ...