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Now showing items 21-30 of 61
Probabilistic estimation of merchant ship source levels in an uncertain shallow-water environment
(2021-11-13)
The estimation of ship source levels (SSLs) in shallow-water environments can be complicated by sound interaction with the seabed. Uncertainty in seabed properties influences SSL estimates, and it is of interest to mitigate ...
Fusing of a continuous output PDR algorithm with an ultrasonic positioning system
(2021-12-09)
The availability of inertial navigation sensors in smartphones has facilitated the development of pedestrian dead reckoning (PDR) models on a large scale. These models often consist of a step detection algorithm combined ...
Holmium-doped fiber amplifier for pumping a ZnGeP2optical parametric oscillator
(2021-03-03)
We present a holmium-doped all-fiber master oscillator power amplifier (MOPA) system operating at 2108 nm targeting optical frequency conversion applications. The MOPA delivers pulses of 0.52 mJ energy at 10 kHz repetition ...
Augmenting Radar Doppler Resolution with Neural Networks
(2021-12-08)
In order to generate high-resolution Doppler profiles a radar needs to emit a large number of pulses within a coherent processing interval (CPI). For a radar operating in demanding scenarios it can be difficult to sustain ...
A Bayesian Network Approach to Evaluating the Effectiveness of Modern Mine Hunting
(2021-10-29)
This paper describes a novel technique for estimating how many mines remain after a
full or partial underwater mine hunting operation. The technique applies Bayesian fusion of all
evidence from the heterogeneous sensor ...
Spectral properties of multilayered oak leaves and a camouflage net: experimental measurements and mathematical modelling
(2021-09-21)
The development of state-of-the-art surveillance technology forces nations to develop camouflage with advanced capabilities. Owing to the abundance and wide distribution of leaves, their spectral properties are often ...
Øke bemanningen i Forsvaret i dramatisk nedgangskonjunktur? En samfunnsøkonomisk vurdering
(2021)
Koronapandemien har resultert i kraftige fall i etterspørsel, produksjon og sysselsetting i Norge
og internasjonalt. Arbeidsledigheten i Norge er nå unormalt høy. Arbeidsøkonomisk litteratur
har påvist at det er kostbart ...
Multibeam Echosounder With Orthogonal Waveforms: Feasibility and Potential Benefits
(2021-04-15)
Modern multibeam echosounders (MBE) employ frequency-division techniques (FDT) to ensonify multiple sectors within the same ping cycle. This leads to improved performance in coverage rate, and yaw and pitch stabilization. ...
Spatial coherence of speckle for repeat-pass synthetic aperture sonar micronavigation
(2021-03-31)
Accurate positioning of autonomous underwater vehicles is a major challenge. The long-term drift is problematic if global position updates are not available, and for applications such as repeat-pass interferometry and ...
Formation Path Following Control of Underactuated USVs
(2021-06-30)
This paper proposes a formation control method for two underactuated unmanned surface vessels (USVs) to follow curved paths in the presence of ocean currents. By uniting a line-of-sight (LOS) guidance law and the ...