Browsing Technical Reports by Title
Now showing items 103-122 of 322
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Detection of narrow-band low-level signals: simulated performance of high-resolution eigenstructure methods versus conventional beamforming
(NATO. SACLANTCEN, 1988/08)In this report the detection of narrow-band low-level signals by passive sonar is addressed, -
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 ... -
Development of a SACLANTCEN MCM sonar performance model
(NATO. SACLANTCEN, 1996/11)The report describes the Mine Countermeasures Sonar Performance -
Development of barotropic models for the GIN Sea
(NATO. SACLANTCEN, 1991/03)Barotropic ocean models are developed for deep oceans, with arbitrary topography and basin geometry, on a sphere. A special adaptation is made for the Greenland-Iceland-Norwegian (GIN) Seas with closed lateral boundaries. ... -
Digital analysis working group: proceedings of a conference held at SACLANTCEN on 25-27 May 1971
(NATO. SACLANTCEN, 1972/05) -
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 -
Direct observation of the angle of intromission in marine sediment
(NATO. SACLANTCEN, 2001/06)High porosity marine sediments like silty clays have the curious property that the speed of sound through its bulk medium is lower than that of the interstitial pore fluid. When a high porosity sediment is at the water ... -
Distortion of bottom reflected pulses
(NATO. SACLANTCEN, 1966/03)The theory of linear systems combined with numerical Fourier transformations and inversion is used to obtain the shape of a general pressure pulse after its reflection from a general multilayered sea floor. The method is ... -
Distributions of magnetic field variations, differences and residuals
(NATO. SACLANTCEN, 1999/02)Temporal and spatial variations of the geomagnetic field were recorded in different geographic areas, -
Drifter and float observations in the Adriatic Sea (1994-1996): data report
(NATO. SACLANTCEN, 1998/12)During the period December 1994 to November 1995, 62 Argos tracked surface drifters, one Argos tracked drifter drogued to 300 m and 3 Argos tracked sub-surface floats were released in the Adriatic Sea to describe the ... -
Drifter observations in the Nordic Seas (1991-1995) data report
(NATO. SACLANTCEN, 1996/02)During the period June 1991 to August 1993, 107 Argos tracked drifters drogued to 15 m depth were released in the Nordic seas (or Greenland-Iceland-Norwegian [GIN] sea) to study the variability of the near-surface circulation ... -
DUSS97: source localization and environmental inversion using vertical array data
(NATO. SACLANTCEN, 1998/08)Results on source localization and environmental inversion using experimental data acquired on a vertical line array are presented. Global inversion methods based on genetic algorithms are utilized to estimated the range ... -
Effects of intrinsic medium inhomogeneities on long-range acoustic transmission
(NATO. SACLANTCEN, 1993/10)Duda et al. [J. Acoust. Soc. Am. 92(2), 939-955, 1992] have measured wavefront arrival times over a -
Efficient global matrix approach to the computation of synthetic seismograms
(NATO. SACLANTCEN, 1986/05)A numerically efficient global matrix approach to the solution of the wave equation in horizontally stratified environments is presented. The field in each layer is expressed as a superposition of the field produced by the ... -
EM phenomena in the ELF range: EM fields of submerged dipoles and finite antennas
(NATO. SACLANTCEN, 1965/06)The report is the first of a series of three that discusses various EM phenomena in the ELF range. The expressions for the various components of the EM field from submerged dipoles are presented. Although similar expressions ... -
EM phenomena in the ELF range: natural background noise and instrumentation for its measurement
(NATO. SACLANTCEN, 1965/06)The report is the second of a series of three that discusses various EM phenomena in the ELF range. A general outline of the natural background noise in the frequency range between 1 and 50 cps is given and the measurement ... -
Estimators for model-based passive localization
(NATO. SACLANTCEN, 1988/07)A comparative study is made of the performance of four different estimators as used in the matched field technique of passive localization. The study is based on both real and synthesized data. In the synthesized data case, ... -
EVA - an evaluator of vague evidence in ASW situations: an expert system prototype
(NATO. SACLANTCEN, 1987/10)This paper presents an example of how an expert system can contribute to the creation and updating -
Experimental demonstration of the focused acoustic field in the ocean
(NATO. SACLANTCEN, 1998/10)An experiment conducted in the Mediterranean Sea in April1996 demonstrated that a time reversal mirror (or phase conjugate array) can be implemented to spatially and temporally refocus an incident acoustic field back to ... -
Extended towed-array processor by overlapped correlator
(NATO. SACLANTCEN, 1988/11)The development of an algorithm for extended towed-array measurements, which could be used by matched-field estimators to obtain information about depth and range of a source, is studied. This algorithm combines coherently ...