Browsing by Type "Scientific Memorandum (SM)"
Now showing items 141-159 of 159
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Testing finite differencing schemes for the shallow water equations
(NATO. SACLANTCEN, 1987/10)The explicit, the semi-implicit, and the fractional step schemes are tested and compared in the -
The application of coupled-mode theory to propagation in shallow water with randomly varying sound speed
(NATO. SACLANTCEN, 1987/06)Sound propagation in the Baltic Sea cannot be described correctly by range independent propagation -
The application of parametric side scan sonar to the detection of proud and buried targets
(NATO. SACLANTCEN, 1998/01)This paper describes an experiment designed to evaluate the feasibility of using the TOPAS parametric transmitter mounted in side scan mode, for the detection of buried targets. The concept was tested with proud targets ... -
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 ... -
The characterization of a range-dependent environment using towed horizontal array data from the MAPEX 2000 experiment
(NATO. SACLANTCEN, 2002/11)The characterization of ocean environments using geoacoustic inversion techniques has received a -
The determination of permeability in in-situ marine-floor sediments
(NATO. SACLANTCEN, 1985/11)A method of evaluating in situ permeability of unconsolidated marine floor sediments has been -
The effect of thermohaline variability on the exchange through Mediterranean straits
(NATO. SACLANTCEN, 1989/05)exchanges through straits. The primary assumption is that the exchange is determined by tlle pressure force created by the differing weights of tlle water columns on either side of the sill and by the continuity of mass ... -
The influence of fluctuations in acoustic travel time on locating the position of an underwater sound source
(NATO. SACLANTCEN, 1985/10)This paper investigates the accuracy of an underwater acoustic positioning system in locating a sound source that transmits at unknown times in conditions in which the acoustic travel times between -
The joint SACLANTCEN/USA towed vertically directive source - TVDS
(NATO. SACLANTCEN, 1996/07)This report is the text of a paper presented at Undersea Defence Technology, Cannes, 1995 (UDT 95). It outlines the development of the Towed Vertically Directive Source (TVDS) and the associated ship-handling and winching ... -
The KRAKEN normal mode program
(NATO. SACLANTCEN, 1991/09)In the late 1970's several normal-mode models existed which were -
Time-evolution modelling of seafloor scatter: Part 1: Theory
(NATO. SACLANTCEN, 1997/04)A time-series model for acoustic seafloor backscattering is described. -
Time-evolution modelling of seafloor scatter: Part 2: experimental verification
(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 ... -
Transmission-loss characteristics and geoacoustic model for an outer Albanian continental shelf platform in the south-east Adriatic sea
(NATO. SACLANTCEN, 1996/03)Transmission-loss experiments have been canied out on the outer Albanian Shelf. The acoustic measurements were performed together with a combined oceanographic and geological-geophysical survey which identified the different ... -
Transmission-time variability, vertical spatial and temporal analysis of NAPOLI'85, an experiment in the Tyrrhenian Sea
(NATO. SACLANTCEN, 1989/09)An acoustic propagation experiment (NAPOLI '85) was carried out in the Tyrrhenian Sea in October 1985 in which signals from a broadband source were recorded at a range of 5 km with a vertical 62-m hydrophone array over a ... -
Upper layer environmental parameters from CTD data - GIN '86 cruise
(NATO. SACLANTCEN, 1989/12)The data from the SACLANTCEN June 1986 Cruise is analysed -
Very low frequency ambient noise measurements in the Ionian Sea: data report
(NATO. SACLANTCEN, 1997/09)This memorandum describes an experiment and provides a data -
Virtual beams from an FFT beamformer and their use to assess the quality of a towed-array system
(NATO. SACLANTCEN, 1983/01)Linear towed arrays with sophisticated signal processing systems have become popular for passive sonar and seismic prospecting. This is due to the ease of mobility and the large spatial gains achievable. However, because ... -
Water masses, sound velocity structure and circulation between the eastern Algerian Basin and the Strait of Sicily in October 1996
(NATO. SACLANTCEN, 2002/01)The investigation is based on data collected between the eastern Algerian Basin and the Strait of Sicily and in the southern Tyrrhenian Sea. The major pathways of water masses are identified by the -
Wave theory modelling of convergence zone propagation in the ocean
(NATO. SACLANTCEN, 1987/06)Improved numerical techniques together with continual advances in computer technology have now