eOyster1 Monitoring by unmanned surface vehicle, eOyster1

An Unmanned Surface Vehicle (USV) is a kind of autonomous marine vehicles which travels on the surface of water and perform missions without human intervention. Thus, the importance of USVs lies in the fact that they are able to carry out tasks in variety of environments without jeopardizing human life.

Currently, USVs are used in variety of missions including pollutant tracking, surveillance operation, mapping of underwater terrain and studying on oceanography. As a country with long coastline and large sea areas, there is a need for efficient patrol and surveillance of the vast Greek Exclusive Economic Zone. Patrolling using traditional resources such as patrol boats and ships puts a strain on operational costs and personnel. A remotely operated unmanned vehicles are expected to carry out the tasks in a more economic and efficient manner. For the past few years, USVs have been developed to perform several missions. At the Massachusetts Institute of Technology (MIT), under MIT Sea Grant College Program in 1993-2000, a number of USVs have been designed. The goal was to develop a light Autonomous Surface Vessel (ASV) to be used as a tool for research purposes, precision survey platform and communication and navigation link to an Autonomous Unmanned Vessel (AUV).

Real-time environmental monitoring systems improve safety offshore and enhance operational efficiency by monitoring meteorological and oceanographic (metocean) conditions. They provide essential, rapid access to data describing the present environmental conditions.

They are used to:

• Monitor meteorological and oceanographic (metocean) conditions critical for safety or efficiency.
• Optimise the planning and execution of operations sensitive to weather or time.
• Comply with legislative requirements.
• Trigger alarms when safe working limits are approached or exceeded.
• Fine-tune weather forecasts using input of real-time data.
• Verify weather forecasts by integrating the display of forecast and measured data.

The recorded data can also provide a valuable resource for deriving engineering criteria and environmental statistics in parameters-indicators such as depth, temperature, pH, specific conductivity, dissolved oxygen, redox potential, total dissolved solids, turbidity, salinity, chlorophyll, algae etc.

The implementation of the Water Framework Directive (WFD) across the EU, and the growing international emphasis on the management of water quality is giving rise to an expanding market for novel, miniaturized, intelligent monitoring systems for fresh water catchments, transitional and coastal waters. The importance of maintaining good water quality highlights the increasing need for advanced technologies to help monitor water and manage water quality. In particular the implementation of the WFD poses new challenges for water managers who have traditionally monitored water quality by taking samples and analyzing them in the laboratory.

The challenges associated with environmental monitoring are various; sensor nodes are deployed in remote places, generally of difficult accessibility and covering wide geographical areas (e.g. river catchments, lakes catchments). Long-term deployments require sensor nodes to be robust and systems to be “easily” reconfigurable/upgradeable. In addition, environmental events are, spatially and temporally, related to eachother (e.g. river catchments: an event happening at the rise of a river might be seen further downstream later on). There is a requirement for the environment to be cost-effectively monitored by an intelligent system giving the required granularity of data in both the temporal and spatial planesto enable an autonomous decision making process to be implemented in real time based on data distributed within the system. These sensor systems need to have a long deployment lifespan, be rugged and robust, have multiple sensor interface capability and be able to operate autonomously in the required environment.

There are many advantages of continuous monitoring. Water quality is of popular interest and real-time water quality monitoring provides a way to verify its suitability for intended uses (e.g. Agriculture/Fishery). In addition, environmental monitoring helps to identify trends in the quality of the aquatic environment, forecast natural phenomena and understand how the environment is affected by the release of contaminants, and/or by waste treatment operations, also known as impact monitoring.Some of the advantages of continuous monitoring versus conventional sampling and laboratory based techniques are listed as follows:

• Possible to monitor remote locations in real-time.
• Faster data availability, enabling a quicker response to events.
• Increased data collection frequency improves understanding of cause-and-effect relationships.
• Provides data sets for developing water quality models.