Technical Reports: Recent submissions
Now showing items 221-240 of 322
-
The sea surface as a random filter for underwater sound waves
(NATO. SACLANTCEN, 1974/06)In this dissertation the phenomenon of scattering and reflection of underwater sound waves from the sea surface is studied by considering the surface sound channel as a random, time-dependent filter. This filter can be ... -
Analysis of Swallow float data at SACLANTCEN: Software notes for future use and developments
(NATO. SACLANTCEN, 1996/02)A Swallow float is as a neutrally buoyant, freely drifting unit which is deployed in deep water, equipped with one pressure sensor (hydrophone) and three orthogonal particle velocity sensors (geophones) to measure acoustic ... -
Comparison of satellite-retrieved sea-surface temperatures with drifter and ship-borne measurements
(NATO. SACLANTCEN, 1996/01)Sea-surface temperatures (SST) retrieved from satellite imagery are compared with in-situ measured data. The satellite data are from the Advanced Very High Resolution Radiometer (AVHRR) of the series of NOAA satellites, ... -
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 ... -
Interpretation and fusion of sonar images using evidential reasoning
(NATO. SACLANTCEN, 1995/12)A method and system architecture for automatic interpretation and fusion of multiple sonar images is proposed. The interpretation of a sonar image consists of the creation of a symbolic geographical map indicating the ... -
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 -
Multiple view sidescan sonar
(NATO. SACLANTCEN, 1995/12)The classification of objects on the seafloor by means of a sonar can be -
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 -
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 -
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) ... -
Reverberation suppression
(NATO. SACLANTCEN, 1995/05)We propose a processing methodology for shallow-water reverberation -
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 ... -
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 ... -
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 ... -
Performance assessment of the SACLANTCEN vertical array in shallow water
(NATO. SACLANTCEN, 1994/03)In this memoranduin the performance of the SACLANTCEN vertical -
Hydrographic measurements in the southern Iceland and Norwegian Seas during June and August, 1989
(NATO. SACLANTCEN, 1993/12)This memorandum documents an extensive collection of CTD data made during two cruises in the region between Greenland and Norway -
Inversion of seismo-acoustic real data using genetic algorithms
(NATO. SACLANTCEN, 1994/03)An inversion scheme for the estimation of the physical parameters -
Measurements for satellite validation made from the RV Alliance during October and November 1991
(NATO. SACLANTCEN, 1993/08)Measurements of sea-surface temperature, surface meteorology and atmospheric profiles were taken from the RV Alliance between 1 October