Browsing by Type "Scientific Report (SR)"
Now showing items 101-110 of 110
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The steady state of the step structure in the Tyrrhenian Sea
(NATO. SACLANTCEN, 1978/10)A deep step structure, in which mixed layers alternate with high gradient interfaces, is a characteristic feature of the Tyrrhenian Sea. Three oceanographic cruises (May 1972, May 1973 and October 1974), supported by the ... -
The wave equation in a medium with a time-dependent boundary
(NATO. SACLANTCEN, 1974/02)It is shown that the Helmholtz equation is not exactly correct for a medium with a time-dependent boundary. The equation can be used with very good approximation when the time-derivative of the surface elevation is much ... -
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 ... -
Toeplitz constrained adaptive beamforming with auxiliary data
(NATO. SACLANTCEN, 1997/02)Submarine and mine detection using active sonar face similar problems when adaptive beamforming is required to provide high angular resolution or to suppress angularly isolated interferences. Both -
Two-dimensional space-series analysis for sea-floor roughness
(NATO. SACLANTCEN, 1979/10)For a quantitative description of the sea-floor roughness, a numerical method has been developed to obtain the two-dimensional power spectrum and the autocorrelation function. The determination of these parameters gives ... -
Underwater photography for quantitative description of bottom roughness
(NATO. SACLANTCEN, 1985/04)Knowledge of the roughness of the sea floor is obviously of great importance in marine geology for understanding the processes of the ocean bottom, and in underwater acoustics for understanding the scattering process. The ... -
Use of the towship for assessing towed-array performance and analyzing data quality
(NATO. SACLANTCEN, 1982/11)A series of relatively simple tests are presented and discussed, which used in conjunction with the noise received from the towship, can be used in real time to assess the performance of a towed array and the quality of ... -
Variability in the Gulf of Cadiz: internal waves and globs
(NATO. SACLANTCEN, 1980/08)An experiment was performed in the Gulf of Cadiz during June 1977, with the objective of separating oceanic variability due to internal waves from that due to inhomogeneities of the water. A CTD which oscillates in depth ... -
Variable sea level and strait flows in the Mediterranean: a theoretical study of the response to meteorological forcing
(NATO. SACLANTCEN, 1983/05)Changes in atmospheric pressure over the Mediterranean are thought to account for a significant part of low frequency sea level changes and associated flow through the Strait of Gibraltar. However, Crepon's (1965) examination ... -
Yellow Shark Spring '95: inversion results from sparse broadband acoustic measurements over a highly range dependent soft clay layer
(NATO. SACLANTCEN, 1998/06)In May 1995, SACLANTCEN performed broad-band (200-800 Hz) acoustic measurements in the Giglio basin off the coast of Italy as part of the Yellow Shark inversion experiments. In this paper, inversion of sparse, broad-band ...