Browsing CMRE Publications by Issue Date
Now showing items 761-780 of 882
-
Sub-bands beam-space adaptive beamformer for port-starboard rejection in triplet sonar arrays
(CMRE, 2019/05)This paper addresses the problem of Port-Starboard (PS) beamforming for low-frequency active sonar (LFAS) with a triplet receiver array. The paper presents a new algorithm for sub-bands beam-space adaptive beamforming with ... -
Extracting acoustic source information of shipping noise for dynamic ambient noise modelling
(CMRE, 2019/05)Shipping traffic is one of the largest contributors to anthropogenic noise in the ocean. Noise generated by merchant ships elevates natural occurring ambient noise level by 20-30 dB in many areas of the world?s ocean. In ... -
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. ... -
Bandwidth efficient concurrent localisation and communication in underwater acoustic networks
(CMRE, 2019/05)Localisation is essential for an Autonomous Underwater Vehicle (AUV) to perform its mission and to georeference any data acquired during the dive. When the AUV is part of a heterogeneous underwater acoustic network (UAN), ... -
An adaptive cross-layer routing protocol for underwater acoustic networks
(2019/05)This short paper presents an adaptive cross-layer routing protocol for Underwater Acoustic Networks (UANs). The proposed solution, termed NADIR for Network Aware aDaptIve Routing, is fully distributed and self-adaptive. ... -
Exploiting phase information in synthetic aperture sonar images for target classification
(CMRE, 2019/05)It is demonstrated that the phase information present in complex high-frequency synthetic aperture sonar (SAS) imagery can be exploited for successful object classification. That is, without using the amplitude content of ... -
Bayesian track-to-graph association for maritime traffic monitoring
(CMRE, 2019/05)We present a hypothesis test to associate ship track measurements to an edge of a given graph that statistically models common traffic routes in a given area of interest. The association algorithm is based on the hypothesis ... -
Liability issues of unmanned surface vehicles
(CMRE, 2019/05) -
Adaptive filter of seabed clutter onboard the AUVs of an active multistatic sonar network
(CMRE, 2019/05)This work aims at reducing the false alarm rate of a multistatic active sonar working in coastal, shallow waters. The sonar system is implemented through a heterogeneous manned-unmanned network including autonomous underwater ... -
The ocean noise coherence matrix and its rank
(CMRE, 2019/05)An expression for the cross-spectral density matrix of ocean noise naturally separates into a Toeplitz part and a Hankel part [Harrison (2017). J. Acoust. Soc. Am. 141, 2812?2820]. The Toeplitz part is shown to be substantially ... -
Recent technological advances in underwater autonomy
(2019/05)Underwater Unmanned systems (or more precisely systems of systems) will definitely play an important role in future maritime surveillance and environmental data collection. For many years, the NATO Centre for Maritime ... -
Fostering marine robotics through competitions: from SAUC-E to ERL Emergency 2018
(CMRE, 2019/05)Marine robotics competitions and challenges are today very popular in the robotics community. Their value mainly lies in the opportunities they provide to teams (both student and professional) for developing and testing ... -
Data driven vessel trajectory forecasting using stochastic generative models
(2019/05)In this work, we propose a data driven trajectory forecasting algorithm that utilizes both recorded historical and streaming trajectory observations. The algorithm performs Bayesian inference on a directed graph the walks ... -
Multi-criteria weather routing optimization based on ship navigation resistance, risk and travel time
(CMRE, 2019/05)This paper presents the analysis of the weather routing scenario in a multi-criteria setup. The set of 3 conflicting criteria is: added navigation resistance (caused by wind and waves), navigation risk and travel time. To ... -
On-board real-time assessment of acoustic environmental parameters relevant to the estimation of sonar performance for autonomous underwater vehicles
(CMRE, 2019/05)CMRE is evaluating the use of autonomous robots for the detection and tracking of underwater targets. Robotic detection and localization comes with many challenges, not the least of which is the requirement to maximize the ... -
A verification, validation and accreditation process for autonomous interoperable systems
(CMRE, 2019/05)Navies, Industries and Research are investigating how to move to future mine counter measure operations where of multiple autonomous underwater vehicles work collaboratively with minimal human interaction. Modelling and ... -
The new muesli complexity metric for mine-hunting difficulty in sonar images
(CMRE, 2019/05)A new image complexity metric has been developed that fuses the concept of lacunarity, a measure of pixel intensity variation, with the notion of spatial information, a quantity that captures edge energy. This new metric, ... -
Multiple Ornstein-Uhlenbeck processes for maritime traffic graph representation
(CMRE, 2019/05)We propose an unsupervised procedure to automatically extract a graph-based model of commercial maritime traffic routes from historical Automatic Identification System (AIS) data. In the proposed representation, the main ... -
A distributed framework for embedded collaborative autonomy
(CMRE, 2019/05)We have designed and implemented a framework for the development and deployment of multi-agent task allocation solutions, with particular awareness of the operational constraints encountered by Unmanned Maritime Systems ... -
Localisation using undersea wireless networks
(CMRE, 2019/05)Underwater navigation for Autonomous Underwater Vehicles (AUVs) is a challenging task, requiring a trade-off between performance, costs and operational time. The project Network Long Base Line (Net- LBL) proposes a system ...