Browsing by Author "Pouliquen, Eric"
Now showing items 1-10 of 10
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Analysis of broad-band echosounder data over a gassy seabed
Boyle, Frank A.; Chotiros, Nicholas P.; Pace, Nicholas G.; Bergem, Oddbjorn; Pouliquen, Eric (NATO. SACLANTCEN, 1997)Calibrated echosoundings from a well-characterized gassy seabed were examined. Acoustic reflection was significantly higher than expected. It is hypothesized that gas bubbles are responsible. Anomalously high levels of ... -
Characteristics of the mediterranean seagrass Posidonia oceanica contributing to high-frequency acoustic scattering
Acunto, Stefano; Lyons, Anthony P.; Pouliquen, Eric (NATO. SACLANTCEN, 2000/05)Posidonia oceanica meadows are the most important ecosystem for the life cycle of coastal Mediterranean benthos with a fundamental role in the primary production of the neritic system and a decisive influence on other ... -
High frequency acoustics in shallow water: proceedings of a conference held in Lerici, Italy, 30 June to 4 July, 1997, organized and sponsored by the NATO SACLANT Undersea Research Centre
High frequency acoustics in shallow water (1997 June 30 - July 4 : Lerici, Italy) (NATO. SACLANTCEN, 1997) -
Mechanisms for subcritical penetration into a sandy bottom: experimental and modelling results
Maguer, Alain; Bovio, Edoardo; Fox, Warren L. J.; Pouliquen, Eric; Schmidt, Henrik (NATO. SACLANTCEN, 1998/05)This paper presents the results of a recent study whose overall objectives are to determine the mechanism(s) contributing to subcritical acoustic penetration into ocean sediments, and to quantify the results for use in ... -
Penetration of acoustic waves into sandy seafloors at low grazing angles: the Helmholtz-Kirchhoff approach
Pouliquen, Eric; Lyons, Anthony P.; Pace, Nicholas G. (NATO. SACLANTCEN, 1998/08)The Helmholtz-Kirchhoff integral is applied to model the penetration of sound waves into sandy seafloors at grazing angles above and below the critical angle. Although the conditions for the validity -
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) -
Seabed characterization by inversion of parametric sonar data: selection of the cost function
Caiti, Andrea; Bergem, Oddbjorn; Pouliquen, Eric; Biancheri, A.; Scaricacciotoli, S. (NATO. SACLANTCEN, 1997)A class of possible cost functions to be used in model-based estimation of bottom parameters from highfrequency backscatter signals is introduced. The cost is based on the properttes of the signal in the wavelettransformed ... -
The effect source movements on shallow water bottom backscatter
Bergem, Oddbjorn; Pouliquen, Eric; Pace, Nicholas G. (NATO. SACLANTCEN, 1997)The time-evolution model BORIS is used to study the effects of source movements on bottom backscatter. Changes in the backscattend time domain signals as functions of source depth, position and incident angles are simulated ... -
Time-evolution modelling of seafloor scatter: Part 1: Theory
Pouliquen, Eric; Bergem, Oddbjorn; Pace, Nicholas G. (NATO. SACLANTCEN, 1997/04)A time-series model for acoustic seafloor backscattering is described. -
Time-evolution modelling of seafloor scatter: Part 2: experimental verification
Bergem, Oddbjorn; Pouliquen, Eric; Canepa, Gaetano; Pace, Nicholas G. (NATO. SACLANTCEN, 1997/04)A time-evolution model of seafloor scatter is numerically implemented and experimentally verified. The model is based on expressing analytically the elementary time-backscattered response of every seafloor surface and every ...