Browsing CMRE Publications by Title
Now showing items 383-402 of 882
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High-resolution beamforming techniques performance analysis
(NATO. SACLANTCEN, 1986/11)Seven different beamforming techniques (including both conventional and high-resolution types) have been analyzed and compared in order to develop a quantitative relationship between resolution performance on the one hand ... -
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-resolution characterization of shallow water sea bottom: need and methodology for a ground-truth reference database
(NATO. SACLANTCEN, 1994/12)A systematic approach to underwater observation of high-resolution seabed features has been developed. These include: morphology caused by current, wave, and biological factors and certain engineering geological factors ... -
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 ... -
Horizontal array gain in shallow water
(NATO. SACLANTCEN, 1980/12)Some results of a comprehensive model study on the use of horizontal hydrophone arrays in shallow water are presented. Well-known signal processing techniques are applied to a shallow-water sound propagation model in order ... -
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) ... -
Hydrographic measurements in the southern Iceland and Norwegian Seas during June and August, 1989
(NATO. SACLANTCEN, 1993/12)This memorandum documents an extensive collection of CTD data made during two cruises in the region between Greenland and Norway -
Hydrography of the Iceland-Faeroe Ridge during March 1992: environmental data during NORDIC 92
(NATO. SACLANTCEN, 1992/12)This memorandum documents an extensive collection of CTD and XBT data made on the Iceland-Faeroe Ridge in March, 1992 by the SACLANTCEN vessel Alliance and the FWG vessel Planet as part of a larger operation called NORDIC ... -
Icelandic current experiment GIN Sea Cruise 88 data report: Hydrography and circulation: volume 1
(NATO. SACLANTCEN, 1992/09)The hydrographic and circulation data from the GIN '88 cruise on board the R/V Alliance are summarised in this data report. This cruise constituted the first component of the Icelandic Current Experiment, an observational ... -
Icelandic current experiment GIN Sea Cruise 88 data report: Hydrography and circulation: volume 2
(NATO. SACLANTCEN, 1992/09) -
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 ... -
Impact of uncertain environmental knowledge on the shallow-water transfer function
(NATO. SACLANTCEN, 1992/12)It is assumed that the acoustic channel can be modeled as a linear time-invariant space-variant filter. In this case, from linear systems theory, it is known that the filter output, that is the predicted source signal ... -
Improvements to data networks in support of REA during Generic Oceanographic Array Technology (GOATS) 98
(NATO. SACLANTCEN, 2000/05) -
Impulse response of a layered bottom
(NATO. SACLANTCEN, 1967/01)Numerical methods are used for the Fourier inversion of the frequency-dependent loss transfer function. Because of the non-zero finite values of the integrand for an infinite high frequency, the asymptotic value is subtracted ...