A CTD device is a package of electronic instruments that measures conductivity, temperature, and depth. Scientists use these devices to measure water quality and better understand species distribution and abundance in the ocean.

CTD’s are attached to a much larger metal frame called a rosette, which holds water-sampling bottles that are used to collect water at different depths and other sensors measuring physical and chemical properties in the ocean.

The data gathered from these devices is then used for algorithm development to understand long time series and extract big patterns of how the natural environment varies from weeks to months to years.

Making the most of this data requires validation, where scientists make measurements from boats, coincident in time with the satellite flying overhead and capturing it’s images. Using validation to ensure the accuracy of data products is crucial if we are to give advice to aquaculture farmers, fishermen or tourists wishing to swim at beaches.

Featured Educators:

• Dr Gavin Tilstone

• Dr Hayley Evers-King

Explore the data

EUMETSAT Oceans MOOC Data Viewer

View featured satellites on the satellite tracking app

Sentinel-3

Don’t forget you can download the video and transcript with the links on the right.