Browsing Reprints by Title
Now showing items 232-251 of 548
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High frequency matched field processing
(NATO. SACLANTCEN, 1997)Results are discussed from a high frequency (0 9-5 7 kHz), very shallow water (<10 m) experiment exploring the feasibility of carrying out matched field processing in this frequency and water depth regime The data was ... -
High resolution feature extraction from reverberation data
(NATO. SACLANTCEN, 1997)A new method of signal approximatzon is presented which has the capability to model complex active returns due to reverberation. The method explored herein is data adaptive in the sense that high resolution processing is ... -
High resolution sonar (tutorial slides)
(NURC, 2010/07) -
High-frequency normal-mode calculations in deep water
(NATO. SACLANTCEN, 1982/10)A method has been developed to perform high-frequency deep-water normal-mode calculations in the multikilohertz region in water depths of the order of 5 km. The results from this technique agree with fast field program ... -
High-resolution characterization of seafloor sediments for modeling acoustic backscatter
(NATO. SACLANTCEN, 1997)Quantitative information on fine-scale sediment inhomogeneity is extremely scarce and sorely needed for developing realistic volume scattering models. To address this deficiency, we present a novel approach for sediment ... -
High-speed simulation of an underwater acoustic field using an array processor
(NATO. SACLANTCEN, 1979/12)A computer model PAREQ for simulating the acoustic field of sound propagating in a complicated ocean environment has been installed on a realtime computer system (HP MX21) which includes an array processor (MAP 300). The ... -
Highlights of bottom topography inferred from received depression and bearing angles
(NATO. SACLANTCEN, 1975/10)Statistical properties of the acoustic reflection from the ocean floor have been studied for a var i.ety of bottom types including deep, smooth, flat topography thorough, jagged bottom in shallower (~l km) depths. Explosive ... -
HLA interoperability for ROS-based autonomous systems
(CMRE, 2019/06)The requirements for autonomous systems (of systems) have started to include the cooperation between heterogeneous assets in order to accomplish complex missions. Therefore, interoperability - both at the conceptual and ... -
Hybrid Bernoulli filtering for detection and tracking of anomalous path deviations
(CMRE, 2019/05)This paper presents a solution to the problem of sequential joint anomaly detection and tracking of a target subject to switching unknown path deviations. Based on a dynamic model described by Ornstein- Uhlenbeck (OU) ... -
Identification of sea surface temperature (SST) variability areas through a statistical approach using remote sensing and numerical ocean model data
(CMRE, 2019/06)An understanding of environmental variability (stability/instability) is important to support operational planning of expeditionary warfare and littoral operations, as well as for preparing the Recognized Environmental ... -
The impact of covariance localization on the performance of an ocean EnKF system assimilating glider data in the Ligurian Sea
(CMRE, 2019/05)Data assimilation through an ensemble Kalman filter (EnKF) is not exempt from deficiencies, including the generation of long-range unphysical correlations that degrade its performance. The covariance localization technique ... -
The impact of sea state on HF surface-wave radar ship detection and tracking performances
(CMRE, 2019/06)Nowadays, we face an ever increasing interest in new technologies and solutions for the maritime surveillance (MS) domain. In such a context, oceanographic high-frequency surface-wave (HFSW) radars have started to get ... -
Impact of seafloor and water column parameter variations on signal-to-background ratio estimates: a sensitivity study based on sonar performance modeling
(NURC, 2006/08)Regardless of how accurate modeling can be, if the set of assumptions made with regard to the propagation conditions are not precise, sonar performance predictions diverge from the corresponding measured values. Here a ... -
In-situ acoustic received level measurements with glider based reactive behaviour
(CMRE, 2019/06)Buoyancy-driven underwater gliders are typically employed to sample the water column environment in the ocean [1]. As one of the efforts of extending the capabilities of traditional underwater gliders, CMRE has been working ... -
Incidence du bruit acoustique de thoniers ligneurs et senneurs français sur leurs performances de peche
(NATO. SACLANTCEN, 1985/01)Les auteurs présentents quelques expertises acoustiques provenant de deux études réalisées par le GERBAM: - la première, sur 95 thoniers ligneurs pratiquant la pêche du germon (Thunnus alalunga), -la second, sur 18 thoniers ... -
Incoherent sub-band averaging for improved target detection and Doppler estimation in linearly frequency modulated continuous active sonar
(CMRE, 2019/05)Linear frequency modulated (LFM) continuous active sonar (CAS) waveforms show promise for use in target tracking given that waveforms can be split into sub-waveforms (sub-bands), thereby increasing the target refresh rate. ... -
Increasing the operational safety of autonomous underwater vehicles using the JANUS communication standard
(CMRE, 2019/05)Increasing the operational safety of Autonomous Underwater Vehicles (AUVs) is necessary to fully explore their potential. Currently, AUV operations are limited by several constrains including the need to guarantee no ... -
Influence of background-noise spatial coherence on high-resolution passive method
(NATO. SACLANTCEN, 1982/06)New signal processing methods for passive listening have appeared recently : they are called "high resolution" methods because they have theoretically a better resolving power than conventional or adaptive beamforming . ... -
Influence of internal waves on sound propagation in the SOFAR channel
(NATO. SACLANTCEN, 1975/10)In this paper theoretical investigations due to the influence of internal waves to sound propagation in the SOFAR-channel are presented. The undisturbed acoustic field is described by a normal-mode model. The disturbance ...