The rapid development of autonomous systems and Information and Communications Technologies (ICT) create new opportunities for maritime activities. Existing autonomous systems are becoming more powerful and utilise the capabilities of several types of devices such as Autonomous Underwater Vehicles (AUVs), Unmanned Surface Vehicles (USVs)sometimes referred as Autonomous Surface Vehicles (ASVs) -, Unmanned Aerial Vehicles (UAVs), moored and drifting systems and, recently emerging, autonomous vessels. Their importance in providing new services in maritime environments is undeniable and the opportunity for coordinated and interconnected operations is clear. However, continuous wide integration of various technologies in maritime environments still faces many challenges. Operations may take place in remote locations, so that dependence on third-party infrastructures such as satellite communication or terrestrial communication systems must be expected. The reliability, performance, availability, and cost of such systems are important issues that need to be tackled. This work reviews the major advancements on state-of-the-art autonomous maritime vehicles and systems, which are used in several different scenarios, from scientific research to transportation. Moreover, the paper highlights how available technologies can be composed in order to efficiently and effectively operate in maritime environments. Highlights of the trade-off between autonomy and communication requirements are provided and followed by an overview of promising communication and networking technologies that could encourage the integration of autonomous systems in maritime scenarios.
Abstract-This paper describes field experiments with an X8 Unmanned Aerial Vehicle (UAV) operating as a wireless communication relay while loitering over a REMUS 100 Autonomous Underwater Vehicle (AUV) being at the ocean surface. The paper describes the design of the communication relay payload, network configuration, optimal flight conditions and UAV antenna mounting, and experimental results. Experiments were conducted under less than ideal conditions with rain and turbulent winds leading to unfavorable roll and pitch motions of the UAV, and small waves surrounding the AUV. The results with data download from the AUV through the UAV communication relay to a ground station shows that at the tested (typical) flight conditions the distance and attitude between the AUV and UAV are not the bottlenecks in the communication network. The main bottleneck was identified as the capacity of the proprietary wireless system on the REMUS 100 AUV which was not specified as a high capacity data link, and seems to be set up by the AUV system manufacturer to provide a relatively low capacity, but very robust, wireless data link regardless of signal strength and quality.
The ArcLight observatory provides hourly continuous time series of
light regime data (intensity, spectral composition, and photoperiod)
from the Arctic, Svalbard at 79° N. Until now, no complete annual time
series of biologically relevant light has been provided from the high
Arctic due to insufficient sensitivity of commercial light sensors
during the Polar Night. We describe a camera system providing all-sky
images and the corresponding integrated spectral irradiance
(
E
P
A
R
) in energy or quanta units,
throughout a complete annual cycle. We present hourly–diel–annual
dynamics from 2017 to 2020 of irradiance and its relation to weather
conditions, sun and moon trajectories.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.