Technical Reports: Recent submissions
Now showing items 41-60 of 322
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Mode and PE predictions of propagation in range-dependent environments: SWAM'99 workshop results
(NATO. SACLANTCEN, 2000/05)Three numerical acoustic models, a coupled normal-mode model (C-SNAP), -
Application of aided inertial navigation system to synthetic aperture sonar micronavigation
(NATO. SACLANTCEN, 2001/01)In order to improve short-term navigational accuracy, critical to successful SAS processing, a highquality Inertial Navigation System (INS) is investigated, which consists of an inertial measurement unit (IMU) and a strapdown ... -
A satellite based ocean forecasting system to support naval operations in crisis situations
(NATO. SACLANTCEN, 2000/05)We employ a nonlinear ocean forecasting technique based on a combination of genetic algorithms and empirical orthogonal function (EOF) analysis. The method is used to forecast the space-time variability of the sea surface ... -
Seismic stratigraphy of the Capraia basin, Northern Tyrrhenian Sea
(NATO. SACLANTCEN, 2001/01)The distribution and thickness of sediments within the Capraia Basin, Northern Tyrrhenian Sea, have been mapped using high-resolution seismic reflection data. The data were studied within the geologic framework determined ... -
Characteristics of the mediterranean seagrass Posidonia oceanica contributing to high-frequency acoustic scattering
(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 ... -
Statistical normalization of non-Rayleigh reverberation
(NATO. SACLANTCEN, 2000/02)Low-frequency active sonar systems operating in shallow water are primarily limited by reverberation. -
On the spatial variability of the impulse response of an underwater acoustic channel
(NATO. SACLANTCEN, 2000/05)In many applications like adaptive equalization, beam-forming, matched field processing or focalization the performance is limited due to changes in the impulse response caused by variations in source-receiver range or in ... -
Passive acoustic detection of marine mammals
(NATO. SACLANTCEN, 2000/04)A passive acoustic analysis of data recorded during the SACLANTCEN -
Target localization with multiple sonar receivers
(NATO. SACLANTCEN, 2000/01)Deployable Underwater Surveillance Systems (DUSS) are a network of small multistatic transmitter/receiver sonar nodes. This study analyzes the contact localization capabilities of DUSS in term of range, time and bearing ... -
Inverse acoustical determination of photosynthetic oxygen productivity of Posidonia seagrass
(NATO. SACLANTCEN, 2000/02)As part of geoacoustic inversion experiments (Yellow Shark) in the Giglio basin, off the west coast of Italy, low frequency, broad-band propagation measurements were performed in the winter and spring of 1995 over a dense ... -
PROSIM broadband normal-mode model: a user's guide
(NATO. SACLANTCEN, 2000/02)PROSIM is a layered normal-mode model approach for adiabatic broadband range-dependent sound -
Long range, large throughput radio data links for DUSS (Deployable Underwater Surveillance Systems)
(NATO. SACLANTCEN, 1999/10)Two mono-directional radio telemetry systems are described operating from a buoy to NRV Alliance at frequencies of 0.4 and 2.28 GHz. Digital data at 2 Mbps were transmitted close to the sea surface, collecting information ... -
Geo-acoustic inversion of the PROSIM'97 experimental data using simplex simulated annealing
(NATO. SACLANTCEN, 2000/01)In the spring of 1997 SACLANTCEN performed an experiment near the Elba island in the Mediterranean Sea. The PROSIM'97 experiment was designed for the validation of a broadband acoustic propagation model. During the period ... -
Deployable underwater surveillance systems: analysis of experimental results: part III
(NATO. SACLANTCEN, 1999/04)Deployable Underwater Surveillance Systems (DUSS) are a new active sonar concept based on a distributed network of small multistatic transmitter / receiver nodes. This study analyzes data acquired during the period 29 June ... -
Bottom scattering measurements in shallow water
(NATO. SACLANTCEN, 1999/08)Sonar performance predictions of reverberation in shallow water rely upon good estimates of the bottom scattering strength. However, little is understood about bottom scattering in shallow water in -
Time series variability in fluctuating ocean waveguides
(NATO. SACLANTCEN, 1999/07)The variability of signals propagating through an uncertain sound speed structure is addressed. Signals are assumed to travel in a narrow band adiabatically in modes and to experience fluctuations in sound speed which are ... -
Data communication and data fusion architecture for RAPID RESPONSE 96-98
(NATO. SACLANTCEN, 1999/06)Executive Summary: The concept of Rapid Environmental Assessment (REA) has emerged in recent years as one of the most interesting research topics in Military Oceanography (MILOC): REA in a military environment is defined ... -
The application of spread-spectrum communications to REA tactical networks and deployable underwater surveillance systems
(NATO. SACLANTCEN, 1999/08)The present document is a part of an ongoing study on advanced communication techniques in support of Rapid Environmental Assessment (REA) and Deployable Undersea Surveillance Systems (DUSS). It aims at the definition of ... -
A high resolution seismic sequence analysis of the Malta Plateau
(NATO. SACLANTCEN, 1999/05)A high resolution seismic study of the Malta Plateau was conducted to characterize the Quaternary sediment layers, mapping their regional extent and determining the environmental conditions during their deposition. Seismic ... -
Accuracy of synthetic aperture sonar micronavigation using a displaced phase centre antenna
(NATO. SACLANTCEN, 1999/02)This work evaluates the accuracy of multi-element synthetic aperture sonar (SAS) micronavigation based on the concept of displaced phase centre antenna (DPCA). The Cramér-Rao lower bound (CRLB) for the joint estimation of ...