Sensor Design and Build
This research, by DCU Water Institute, is focused on optimising the Optical Colourimetric Sensor (OCS) to capture the key marine water quality properties which are essential in monitoring change, creating modelling and prediction trends. The next-generation sensor aims to be low-cost, robust, re-deployable and suitable for deployment by a wide range of infrastructure. The LED Array consists of 5 specifically chosen surface mounted LEDs of different wavelengths ranging from the UV to the InfraRed spectrum. Each wavelength of the LEDs corresponds to the detection and measurement of a particular element present in the water such as coloured dissolved organic matter (CDOM), chlorophyll, algae and turbidity.
Lab testing will be carried out using an optical chamber specifically designed to test the optical components, light source and sensor placement for the sensor design. The chamber is 3D printed using matte black material to reduce light reflection within the chamber. The light source and the photodetectors are positioned at specific distances and angles around the chamber behind UV optical windows which are waterproofed with O-rings and silicone sealant. The electronic circuitry processes the signal output from the sensors and is read by a microcontroller.
Deployment & Testing
Validation studies will be carried out using laboratory-based tests for water colour, suspended solids, total organic carbon and field deployments using in-situ devices for turbidity, chlorophyll, hydrocarbon detection etc. From targeted engagement activities with coastal stakeholders, test locations will be selected based on needs and specific water quality issues. One of the key features of the sensor and communications software design, is the adaptability to various environments. In order to deliver a reliable spatially relevant network of sensors, the sensors may be deployed via water buoys or fixed to existing coastal structures.
Data Collection, Analysis & Monitoring
In line with the objective of the project, to provide an advanced environmental decision support system to address issues such as coastal pollution and water quality monitoring, near-real-time data will be integrated into an advanced platform for data analytics and development of a validated decision support tool.
The proposed data analytics platform will be based on TechWorks Marine’s proprietary platform CoastEye which has been operational since 2012. This is a custom, secure web portal, developed in house, which provides access to temporal and spatial data from a variety of sources (e.g. land/ocean based sensors, satellite data, wave models). Satellite data from the European Space Agency (which is freely available) is also integrated in CoastEye on a rolling basis, building upon archives of satellite data stretching back decades. The data content of the system is very flexible and can accommodate many different types and formats of data.
The data analytics platform will have the following functionality:
Data ingestion (multiple sources such as in-situ, satellite, model, and map layer data)
Status of instruments operating
Processing chains developed for the incoming data
Output of data in:
– Graphical format for use in reporting,
– Map layer format for integration into GIS applications,
– Text format for further analysis.