| dc.description.abstract | This thesis highlights how unmanned vehicles can be utilised to boost selected maritime natural sciences research scenarios in remote locations, such as the Arctic The thesis is divided into two parts. In the first part (Background and motivation of research on systems of unmanned vehicles for natural sciences) some important natural sciences problems are described, providing a number of proof-ofconcept applications where use of systems of unmanned vehicles can boost research activities.
• Chapter 2 describes experimental setup and results on light climate research in Ny-Ålesund between fall 2016 and summer of 2018.
• Chapter 3 describes the design of a prototype ice-tethered buoy carrying underwater sensors and lessons learned during a half-year-long test in relevant environment.
• Chapter 4 presents a conceptual design and field test validation of a network of surface nodes providing a communication bridge between underwater sensors and Unmanned Vehicles (UV).
• Chapter 5 presents a proof-of-concept for an hydro acoustic fish-tag position estimation and tracking system using a formation of UVs.
Main scientific contributions in these chapters are: (1) a full-year data series of light climate in Ny-Ålesund, including details on dark period of polar night, (2) a system of a mobile array of acoustic receivers that allow to track an underwater tag (e.g. fish) beyond the range of the classic stationary arrays, and provides a real-time data about tag presence and position, (3) a design of sensor buoys to support research on underwater fauna.
These first chapters also indicates that lack of that reliable communication in the Arctic regions and other remote locations is a significant bottleneck that needs to be addressed.
In part two of the thesis (Communication and networking using systems of unmanned vehicles) author looks into variety of technologies and possible solutions to increase communication capabilities in the remote regions. A special attention is put on a use of autonomous platforms as relay nodes and data-mules.
• Chapter 6 reviews the major advancements on communication in state-ofthe-art autonomous maritime vehicles and systems, which are used in several different scenarios, from scientific research to transportation.
• Chapter 7 presents a system architecture for enabling advanced field operations, allowing researchers to reduce required effort in developing a Unmanned Aerial System.
• Chapter 8 presents performance anlysis of a network system architecture used during an experiment where 8 departments from 5 institutions worked together to combine operation of 4 UVs (aerial, surface, underwater), a support vessel and on-shore team.
• Chapter 9 describes a performance analysis of a field experiments with an Unmanned Aerial Vehicle (UAV) operating as a wireless communication relay while loitering over an Autonomous Underwater Vehicle (AUV) being at the ocean surface.
• Chapter 10 investigates factors that influence the performance of UAVs use as data mules, capable of flying over large distances and retrieving data from remote locations.
• Chapter 11 proposes an integrated network, consisting of a combination of dedicated small satellite systems and unmanned vehicles to help in data retrieval in remote locations.
The main contributions of these chapters are: (1) field-validation of different types of communication and network technologies, including the licence-free and proprietary radios, (2) a set of systems architectures that could be utilised in multivehicle operations, (3) an analysis that in realistic scenarios UAV based data-muling can be a good application for Delay Tolerant Network (DTN) technology.
In summary, a number of scenarios, focused on realistic scenarios and natural science research, are analysed using an experiment-driven methodology. Results show that UVs can be successfully employed to collect sensor data or rely communication links, therefore positively influence field-research and capabilities of existing systems. | nb_NO |
