Browsing by Title
Now showing items 131-150 of 882
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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 ... -
Anomaly detection and tracking based on mean-reverting processes with unknown parameters
(CMRE, 2019/05)Piecewise mean-reverting stochastic processes have been recently proposed and validated as an effective model for long-term object prediction. In this paper, we exploit the Ornstein-Uhlenbeck (OU) dynamic model to represent ... -
Antisubmarine warfare applications for autonomous underwater vehicles: the GLINT09 field trial results
(NURC, 2012/05)Surveillance in antisubmarine warfare (ASW) has traditionally been carried out by means of submarines or frigates with towed arrays. These techniques are manpower intensive. Alternative approaches have recently been suggested ... -
Application of aided inertial navigation system to synthetic aperture sonar micronavigation
(NATO. SACLANTCEN, 2001/01)In order to improve short-term navigational accuracy, critical to successful SAS processing, a highquality Inertial Navigation System (INS) is investigated, which consists of an inertial measurement unit (IMU) and a strapdown ... -
Application of beam-forming techniques to measurements of acoustic scattering from the ocean
(NATO. SACLANTCEN, 1986/10)Signals from an explosive source backscattered from the seafloor and received at long range by -
Application of ray tracing with horizontal gradient to monostatic boundary reverberation
(NATO. SACLANTCEN, 1971/12)Presented is the current work being done at the Naval Research Laboratory (NRL) on the development of a series of computer programs to predict long range, low frequency, monostatic boundary reverberation. The emphasis is ... -
Application of real data to sonar detection by neural networks
(NATO. SACLANTCEN, 1992/11)This memorandum describes the results of applying an artificial neural network for the detection of target echoes. The present study is a continuation of work conducted in 1989 in which a three-layer artificial neural ...