CMRE Open Library: Recent submissions
Now showing items 201-220 of 882
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Efficient dense sonar surveys with an autonomous underwater vehicle
(CMRE, 2014/01)An algorithm for the in situ adaptation of the survey route of an autonomous underwater vehicle (AUV) equipped with side-looking sonars was recently proposed. This algorithm immediately exploits the through-the-sensor data ... -
Optimum sampling designs for a glider-mooring observing network
(CMRE, 2014/01)Ocean observing systems (OOSs) constituted by moorings and gliders are becoming relevant in oceanographic and climate studies. In these observing networks, the temporal variability is captured by mooring observations, while ... -
Range estimation of cetaceans with compact volumetric arrays
(CMRE, 2014/01)Passive acoustic monitoring is the method of choice to detect whales and dolphins that are acoustically active and to monitor their underwater behaviour. The NATO Science and Technology Organization Centre for Maritime ... -
Vessel pattern knowledge discovery from AIS data: a framework for anomaly detection and route prediction
(CMRE, 2014/01)Understanding maritime traffic patterns is key to Maritime Situational Awareness applications, in particular, to classify and predict activities. Facilitated by the recent build-up of terrestrial networks and satellite ... -
Ray convergence in a flux-like propagation formulation
(CMRE, 2014/01)The energy flux formulation of waveguide propagation is closely related to the incoherent mode sum, and its simplicity has led to development of efficient computational algorithms for reverberation and target echo strength, ... -
A relation between multipath group velocity, mode number, and ray cycle distance
(CMRE, 2014/01)Weston's ray invariant or "characteristic time" in a range-dependent environment is exactly equivalent to the Wentzel-Kramers-Brillouin phase integral for ducted normal modes. By considering a ray element it is shown that ... -
Oceanographic field estimates from remote sensing and glider fleets
(CMRE, 2014/01)This work investigates the merging of temperature observations from a glider fleet and remote sensing, based on a field experiment conducted in an extended coastal region offshore La Spezia, Italy, in August 2010. Functional ... -
The temperature structure in the upper layers of the Ligurian Sea and its seasonal variations: supplement to SACLANTCEN technical report no. 8
(NATO. SACLANTCEN, 1964/04)Water temperature measurements, down to depths of 150 meters, and metereological data connected with these measurements carried out in t 1e Ligurian Sea in May and November 1962, are presented in the form of graphs and ... -
GLider Acoustics Sensing of Sediments (GLASS): experiments and data analysis
(CMRE, 2013/12)Seabed characteristics (geoacoustic properties and scattering strength) are critical parameters for sonar performance predictions. However, this bottom information is considered very difficult and expensive to achieve in ... -
Counter piracy surveillance requirements for early detection, military rescue, or evasion
(NURC, 2012/06)Best practice for protection against pirates includes coordination with the military forces operating in the area, constant watch against the approach of pirates, and measures to prevent or delay their boarding. The time ... -
On adaptive underwater object detection
(NURC, 2012/04)A new algorithm for the detection of underwater objects in sonar imagery is proposed. One particularly novel component of the algorithm also detects the presence of, and estimates the orientation of, sand ripples. The ... -
Adaptive autonomous underwater vehicles for littoral surveillance: the GLINT10 field trial results
(NURC, 2012/05)Autonomous underwater vehicles (AUVs) have gained more interest in recent years for military as well as civilian applications. One potential application of AUVs is for the purpose of undersea surveillance. As research into ... -
A contribution to the study of surface and subsurface zooplankton in the Strait of Sicily
(NATO. SACLANTCEN, 1972/09)Analysis of 71 hauls of plankton in the Strait of Sicily, from 2 February to 16 March 1966, enabled us to make a systematic, quantitative and ecological study of all zooplankton systems present. A synthesis was made, from ... -
A review of some developments in ray tracing at the Naval Air Development Center
(NATO. SACLANTCEN, 1971/12)The Naval Air Development Center has a comprehensive ray-tracing program which has been extensively used for a number of years not only by our own laboratory, but also by other naval activities and private contractors . ... -
AUV-enabled adaptive underwater surveying for optimal data collection
(NURC, 2012/04)A new adaptive strategy for performing data collection with a sonar-equipped autonomous underwater vehicle (AUV) is proposed. The approach is general in the sense that it is applicable to a wide range of underwater tasks ... -
Volumetric distribution of oceanographic fields estimated from remote sensing and in situ observations from autonomous underwater vehicles of opportunity
(NURC, 2012/04)A main challenge of military oceanography (MILOC) is to assess the oceanographic conditions of denied/highrisk marine regions. Monitoring technologies are limited to those that can provide access to these regions. Remote ... -
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 ... -
The relation between the waveguide invariant, multipath impulse response, and ray cycles
(NURC, 2012/04)The waveguide invariant, b, that manifests itself as interference fringes or "striations" in a plot of frequency vs source-receiver separation, is usually thought of as a modal phenomenon. This paper shows that striations ... -
Target time smearing with short transmmissions and multipath propagation
(NURC, 2012/04)In active sonar the target echo level is often estimated with a propagation model that adds all multipath arrivals. If the (post-correlator) transmitted pulse is short compared to the multipath time spread then there is ...