Browsing by Author "Pace, Nicholas G."
Now showing items 1-7 of 7
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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 ... -
Generic Oceanographic Array Technologies (GOATS)'98: bi-static seabed scattering measurements using autonomous underwater vehicles
Schmidt, Henrik; Maguer, Alain; Bovio, Edoardo; Fox, Warren L. J.; LePage, Kevin D.; Pace, Nicholas G.; Hollett, Reginald D.; Guerrini, Piero; Sletner, Per Arne; Michelozzi, Enzo; Moran, B.; Grieve, R. (NATO. SACLANTCEN, 1998/10)The GOATS'98 experiment was performed May 5-29, 1998 in shallow water off Marciana Marina, on the island of Elba, Italy. The experiment addressed some of the fundamental issues associated with using the new Autonomous Ocean ... -
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) -
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 -
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 ...