Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic

This is a post-peer-review, pre-copyedit version of an article published in Polar Biology. The final authenticated version is available online at https://doi.org/10.1007/s00300-018-2368-4.The jellyfish Periphylla periphylla, which can have strong ecological impacts on its environment, is ubiquitous in the Norwegian Sea and its range was predicted to extend northwards. The occurrence of P. periphylla in the northern Barents Sea increased since 2014 and, for the first time, several individuals were collected within a high Arctic fjord (> 78°N) in western Spitsbergen in January 2017. The low solar irradiance prevailing during the polar night and an increased inflow of relatively warm Atlantic water in the European Arctic since the last decade likely provide suitable conditions for the medusa to colonize Svalbard’s fjords during the winter months. However, light avoidance constrains the photophobic P. periphylla to deeper offshore areas during the midnight sun period. The current occurrence of P. periphylla in high Arctic fjords during the polar night will have a limited impact on marine ecosystems in the short term, but long-term effects are more uncertain if its abundance continues to increase

Ultra-Wide Band Real Time Location Systems: Practical Implementation and Performance Evaluation

Several different methods can be used to determine the 3-dimensional position of an object. A common solution is use of Global Navigation Satellite System (GNSS). However, for some operation the specific characteristics of GNSS can be challenging, e.g. time-to-fix on GPS RTK or unavailability of GNSS signals. When considering operations within limited range (a few hundreds of meters) another solution based on Ultra-wideband Real Time Location Systems (UWB RTLS). In this paper authors have tested a set-up of a tag and five anchors in order to determine if such solution can be used in local operations of Unmanned Aerial Vehicles (e.g. landing). Experimental data are analyzed and compared against GPS RTK measurements

Unmanned Aerial Vehicles as Data Mules: An Experimental Assessment

Communication in remote locations, specially in high-latitude regions, such as the Arctic, is challenged by the lack of infrastructures and by the limited availability of resources. However, these regions have high scientific importance and require efficient ways of transferring research data from different missions and deployed equipment. For this purpose, unmanned aerial vehicles (UAVs) can be used as data mules, capable of flying over large distances and retrieving data from remote locations. Despite being a well-known concept, its performance has not been thoroughly evaluated in realistic settings. In this paper, such a solution is evaluated through a field-experiment, exploiting the obtained results to define and implement an emulator for intermittent links. This emulator was designed as a mission planning tool, where we further analyze the impact of different flight trajectories when retrieving data. Additionally, we study the overall performance of 4 well-known file-transferring protocols suitable for a UAV being used as a data mule. Our analysis shows that trajectories at higher altitudes, despite increasing distance between nodes, improves communication performance. Moreover, the obtained results demonstrate that DTN2, using the bundle protocol, outperforms FTP, Rsync, and SCP, and that all these protocols are affected by the size of the files being transferred. These results suggest that, in order for the scientific community to practically use UAVs as data mules, further studies are required, namely on how different UAV trajectories can be combined with efficient file-transferring network protocols and well organized data structures

Unmanned Aerial Vehicle as Communication Relay for Autonomous Underwater Vehicle - Field Tests

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

Solid State Sensors - Practical Implementation in Unmanned Aerial Vehicles (UAVs)

AbstractLast two decades of advances in sensors, electronics and wireless communication, as well as dramatic increase of computing power of integrated microprocessors and microcontrollers have opened new perspectives for Unmanned Aerial Vehicles (UAVs). Such systems became smaller, more endurable and cheaper, accessible not only for military clients, but also for civilian applications. One of the most important components of an UAV is a set of sensors, used to acquire both real-time flight and system control data. Mini-class electric-powered UAV (wingspan up to 4 meters, take-off weight up to 50kg) consists of more than twenty different sensors, including Pitot and static pressure sensors (for airspeed, altitude and vertical speed measurements), inertial and angular rate sensors, and the most important for surveillance missions, day and night imaging sensors

A Formation of Unmanned Vehicles for Tracking of an Acoustic Fish-Tag

In this paper we present a proof-of-concept for an hydro acoustic fish-tag position estimation and tracking system. In our field-tested concept, a formation of Unmanned Surface Vehicles (USV) creates a mobile array of low-cost hydro acoustic fish-tag receivers. The array of receivers is able to estimate fish-tag locations and follow the fish on open waters, significantly increasing capabilities as compared to moored systems. The paper describes the system architecture and components in detail. It also evaluates the proof-of-concept characteristics based on the experience gathered during the field-test

Coordinated maritime missions of unmanned vehicles - network architecture and performance analysis

Multi-vehicle operations using various types of unmanned vehicles (UVs) can increase efficiency of marine data acquisition, reduce the crew risk and lower mission costs. These types of missions are very complex and often involve systems that are not interoperable. From an operational perspective however, some level of integration is necessary. Typically, a common network system architecture and Situation Awareness (SA) platform are required. The architecture allows operators to transfer data between vehicles and their operators, while the SA platform allows to monitor mission progress and react to changes. This paper presents a network system architecture used during an experiment realized in Spring 2016 in Norway. 8 departments from 5 institutions worked together to combine operation of 4 UVs (aerial, surface, underwater), a support vessel and on-shore team. The description is followed by a backbone network performance analysis. Several cases are presented, with focus on a transmission between manned vessel and Unmanned Surface Vehicle (USV), including direct connection, and data-relay mechanism via Unmanned Aerial Vehicle (UAV)

Unmanned Aerial System for deployment and recovery of research equipment at sea

In this paper we present details of Miniature Underwater Gliders (MUG) deployment and recovery mechanism using a multirotor Unmanned Aerial Vehicle (UAV). The paper discusses details of MUG localization with computer vision, pick-up algorithm, and recovery mechanism

Coordinated maritime missions of unmanned vehicles — Network architecture and performance analysis

Multi-vehicle operations using various types of unmanned vehicles (UVs) can increase efficiency of marine data acquisition, reduce the crew risk and lower mission costs. These types of missions are very complex and often involve systems that are not interoperable. From an operational perspective however, some level of integration is necessary. Typically, a common network system architecture and Situation Awareness (SA) platform are required. The architecture allows operators to transfer data between vehicles and their operators, while the SA platform allows to monitor mission progress and react to changes. This paper presents a network system architecture used during an experiment realized in Spring 2016 in Norway. 8 departments from 5 institutions worked together to combine operation of 4 UVs (aerial, surface, underwater), a support vessel and on-shore team. The description is followed by a backbone network performance analysis. Several cases are presented, with focus on a transmission between manned vessel and Unmanned Surface Vehicle (USV), including direct connection, and data-relay mechanism via Unmanned Aerial Vehicle (UAV)

Survey on Communication and Networks for Autonomous Marine Systems

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.acceptedVersio