Browsing CMRE Publications by Title
Now showing items 125-144 of 882
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An experimental investigation of the contribution of sediment volume scattering to acoustic backscatter measured in the shallow waters of the Florida Strait
(NATO. SACLANTCEN, 1997)Experiments were conducted in the Florida Strait region of the United States in July 1995 for the purpose of investigating the contribution of sediment volume scattering to measured backscatter levels at frequencies between ... -
An experimental study in forming a long synthetic aperture in the sea
(NATO. SACLANTCEN, 1992/09)Successful experimental testing of synthetic aperture techniques for sonar systems have been very limited and only few results, including very stable CW signals, have been published. These experimental results and theoretical ... -
An experimental study of sediment discrimination using 1st and 2nd echoes
(NATO. SACLANTCEN, 1997)Analysis of Roxann seabed classification data, at 24 kHz and 200 kHz, using co-located echosounders is presented. Timeseries backscater data gathered at the same time as the Roxann data has also been anal~sed using variations ... -
An experimental verification of a geometric acoustic approximation
(NATO. SACLANTCEN, 1971/12)This paper sets out to show that a very simple ray treatment may be used to give a surprisingly good estimate of a sound field, even in conditions where the criteria for the use of geometric acoustics are apparently not fulfilled. -
An improvement in the design of the towed nuclear spin magnetometer
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An instrument for measuring evaporation
(NATO. SACLANTCEN, 1965/09)An evaporation rate meter, or evaporimeter, has been devised that shows promise of directly measuring the rate of evaporation near the sea surface. The simplicity of the instrument indicates that it may be of interest to ... -
An introduction to adaptive array processing
(NATO. SACLANTCEN, 1979/12)Array processing systems which can respond to an unknown interference environment are currently of considerable interest. The fundamentals of such systems are by no means new - basically they depend on Weiner's filter ... -
An unrestricted linear random walk with negative exponentially distributed step lengths
(NATO. SACLANTCEN, 1966/06)An account is given of the theory of a doubly infinite linear random walk in which step lengths have a negative exponential distribution and the direction of each step is not necessarily equiprobable. The problem of first ... -
Analysis and problems of HF acoustic coherent and incoherent simulations in shallow water
(NATO. SACLANTCEN, 1997)Shallow water environments create complex scattering condit~ons due to the sea surface and bottom scattering mechanisms. An analysis of the effects of the scattering mechan~smso n sonar images of simple targets in shallow ... -
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 ... -
Analysis of basin backscattering in the Levantine Sea
(NATO. SACLANTCEN, 1989/12)Research has been conducted in the Levantine Sea basin to measure low-frequency basin reverberation and relate the measurements to backscattering strength. The receivers were a towed horizontal array and a suspended vertical ... -
Analysis of broad-band echosounder data over a gassy seabed
(NATO. SACLANTCEN, 1997)Calibrated echosoundings from a well-characterized gassy seabed were examined. Acoustic reflection was significantly higher than expected. It is hypothesized that gas bubbles are responsible. Anomalously high levels of ... -
Analysis of JANUS and underwater telephone capabilities and co-existence
(CMRE, 2019/06)This document aims at offering a concise look into the co-existence of Underwater Telephone and JANUS digital communication methods. This topic is of particular interest as both methods (one a well-established STANAG and ... -
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 ... -
Analysis systems for the mesoscale thermal variability in the Greenland-Iceland-Norwegian Sea
(NATO. SACLANTCEN, 1988/07)Mesoscale thermal structure and its spatial variability are very significant for acoustic propagation in the ocean. Therefore ocean thermal analysis procedures are important for the initialisation andverification of ... -
Annual Progress Report 1999
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Annual Progress Report 2000
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Annual Progress Report 2001
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Annual Progress Report 2004
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Annual Progress Report 2005
(NURC, 2006/03)This Progress Report describes the Centre's unclassified technical accomplishments and outputs realised under the Scientific Programme of Work (SPOW) for 2005. The Centre conducts maritime research in support and anticipation ...