R&D and Education

Gema Casal, Xavier Monteys, John Hedley, Paul Harris, Conor Cahalane and Tim McCarthy (2018) Assessment of empirical algorithms for bathymetry extraction using Sentinel-2 data, International Journal of Remote Sensing, DOI: 10.1080/01431161.2018.1533660

Bathymetry estimated from optical satellite imagery has been increasingly implemented as an alternative to traditional bathymetric survey techniques. The availability of new sensors such as Sentinel-2 with improved spatial and temporal resolution, in comparison with previous optical sensors, offers innovative capabilities for bathymetry derivation.

This study presents an assessment of the fit between satellite data and the underlying models in the most widely used empirical algorithms: the linear band model and the log-transformed band ratio model using Sentinel-2A data. Both models were tested in two study areas of the Irish coast with different morphological and environmental conditions. Atmospheric correction, bottom type influence, and water column conditions proved to be key factors in the bathymetric derivation using these satellite datasets.

Download the publication here: https://www.tandfonline.com/doi/abs/10.1080/01431161.2018.1533660

Assessment of Empirical Algorithms for Bathymetry Extraction Using Sentinel-2 Data

Gema Casal, Xavier Monteys, John Hedley, Paul Harris, Conor Cahalane…

Anu Marii Kaskela, Aarno Tapio Kotilainen, Ulla Alanen, Rhys Cooper, Sophie Green, Janine Guinan, Sytze van Heteren, Susanna Kihlman, Vera Van Kancker, Alan Stevenson and the EMODnet Geology Partners.

Geosciences 2019, 9(2), 84; https://doi.org/10.3390/geosciences9020084

The importance of an integrated knowledge on seafloor sediment distribution for European seas is highlighted in work just published: "Picking up the pieces – harmonising and collating seabed substrate data for European maritime areas" in the Geosciences Special Issue on "Geological Seafloor Mapping".

The publication describes how the European Marine Observation and Data Network (EMODnet) initiated by the European Commission, has assembled and provided free access to marine geological data through a web data portal.

EMODnet Geology Seabed Substrate Confidence Levels

EMODnet Geology has collated all available seabed substrate maps for European seas to create multiple maps at different scales and Folk granularities, where Folk refers to the internationally recognised Folk classification scheme. INFOMAR contributes data on Ireland’s seabed substrate distribution from all surveyed coastal areas extending to the deeper water depths ~4500 m.

A confidence assessment of the data is provided to ensure users understand the ‘confidence’ in the map reflecting the amount of information available from acoustic data and seabed samples to create the map. INFOMAR data has an associated high level of confidence for much of the Irish offshore highlighting the benefits of full coverage survey data in Ireland’s Exclusive Economic Zone.

Information on seabed substrates is particularly valuable for marine spatial planning where it facilitates investment in sustainable coastal and offshore activities through better access to standardised marine data.