Browsing Technical Reports by Issue Date
Now showing items 161-180 of 322
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Sea-surface winds in the Iceland-Faeroe area, as derived from the ERS-1 scatterometer
(NATO. SACLANTCEN, 1994/04)This report presents measurements of surface meteorological data taken during three cruises of R/V Alliance to the Iceland-Faeroe frontal area during August 1991 (NORDIC'91), March 1992 (NORDIC'92a) and October 1992 ... -
Instrumentation for crosshole geoacoustic measurements in unconsolidated sediments
(NATO. SACLANTCEN, 1994/06)Research tools are described that enable direct measurements of sediment properties as a function of depth in unconsolidat,ed sediments. The first tool is a hole making device that sits on the sea floor and utilizes pneumatic ... -
High-resolution characterization of shallow water sea bottom: need and methodology for a ground-truth reference database
(NATO. SACLANTCEN, 1994/12)A systematic approach to underwater observation of high-resolution seabed features has been developed. These include: morphology caused by current, wave, and biological factors and certain engineering geological factors ... -
Inversion for geometric and geoacoustic parameters in shallow water: experimental results
(NATO. SACLANTCEN, 1994/12)Experimental results on the estimation of both geometric and geoacoustic parameters in shallow water are presented. Genetic algorithms are used for estimation of the forward model parameters, the -
Shallow seafloor geology and sediment character ofthe western Mallorca Platform
(NATO. SACLANTCEN, 1995/03)A site survey of the seabottom west of Mallorca in the central Balearic Islands has characterized the bottom and the immediate sub-bottom. High resolution seismic reflection Uniboom, deeper penetrating (about 5x Uniboom) ... -
Acoustic models at SACLANTCEN
(NATO. SACLANTCEN, 1995/03)The Environmental Modelling Group at SACLANTCEN maintains a suite of computer codes to model sound propagation in the ocean. This suite contains numerical models to cover all environmental conditions and acoustic frequencies ... -
Geoenvironmental characterization of selected shallow-water sites on the western European continental shelf (SWAP)
(NATO. SACLANTCEN, 1995/04)Geoenvironrnental analyses for four experiment sites on the continental -
Reverberation suppression
(NATO. SACLANTCEN, 1995/05)We propose a processing methodology for shallow-water reverberation -
Statistical characteristics of large-scale bottom reverberation
(NATO. SACLANTCEN, 1995/07)Simulation results from a statistical characterization of large-scale bottom reverberation from broadband signals are presented. The seafloor profile is parametrized via the surface root-mean-square height and correlation ... -
Benchmarking scattering in ocean waveguides
(NATO. SACLANTCEN, 1995/07)Accurate numerical solutions are presented for benchmark problems -
Digital map and linked data (DMap) implementation at SACLANTCEN as an aid to sea-going research
(NATO. SACLANTCEN, 1995/08)DMaps (data maps), consisting of a geographical informatiorl system -
Single mode excitation, attenuation and backscatter in shallow water
(NATO. SACLANTCEN, 1995/10)Normal mode theory is used to illustrate that a vertical array of weighted sources driven in an -
Detection of buried mines using Rayleigh-scattered second-derivative Gaussian pulses
(NATO. SACLANTCEN, 1995/10)Large ground mines which are intentionally or unintentionally buried in the sediment have proven to -
PC-based propagation and sonar prediction models
(NATO. SACLANTCEN, 1995/12)Six acoustic models available for use on PC's are tested on a series of typical propagation situations from the North Atlantic and the Mediterranean. The model set includes both early US Navy models (ASTRAL, FACT, RAYMODE) ... -
Robust normalization algorithms for low-frequency active sonar signals
(NATO. SACLANTCEN, 1995/12)Two normalization processors of active sonar signals are presented. Due to their specific design, these algorithms are particulary good candidates to normalize the data stream before applying postprocessing methods based ... -
Acoustic bottom characterization of a shallow water area west of Mallorca
(NATO. SACLANTCEN, 1995/12)An experiment was conducted in shallow water on the Balearic Shelf -
Multiple view sidescan sonar
(NATO. SACLANTCEN, 1995/12)The classification of objects on the seafloor by means of a sonar can be -
Measurements and predictions of transmission loss at two sites in the Southwest Approaches to the English Channel
(NATO. SACLANTCEN, 1995/12)As part of a continuing series of measurements being made by -
Detection of objects on a non Rayleigh background
(NATO. SACLANTCEN, 1995/12)Sector scanning sonar systems image the sea-bottom to detect objects that can be distinguished from the background structure of the seabottom. In current systems images are displayed and discarded as new image data become ... -
Analysis of a signal starting time estimator based on the Page test statistic
(NATO. SACLANTCEN, 1995/12)The time of the most recent reset to zero of the Page test statistic is proposed as an estimator of the starting time of a signal. The probability mass function of the estimator is determined analytically subject to a ...