SEAmBOTH in SDBday -satellite derived bathymetry technology and user forum

Even with ‘traditional’ mapping methods maintaining a crucial role in biological conservation, emerging new technologies enable us to work to a larger degree behind a computer screen. The increased quality and availability of satellite images is something that we are interested to utilize in SEAmBOTH.

The plus side for satellite images is that they are updated regularly, so even if you must skip some that have clouds obstructing the view, you can usually get recent images. And you can always get a timeline of images to track changes over time. They also cover huge areas, so a large amount of data can be extracted if the images can be classified.

The quality of satellite images enables researchers to determine for example water depth from the images and ecological information about underwater vegetation. The method is based on the way the sea bottom reflects different band widths of light. This information can then be used with algorithms to measure water column depth. The challenge in the Bothnian Bay is water turbidity. If the light doesn’t penetrate to the bottom, you can’t get any information on it. The good news is that the water is very shallow, so the penetration doesn’t have to reach all that far and the deeper areas can be covered by sonar.

Why we need accurate and comprehensive depth data? Depth is the base for a lot of modelling that we are doing in SEAmBOTH. The better the data, the better the models will be. Now this isn’t to say that we are dependent on satellite based depth, but it helps.

Satellite derived bathymetry and user conference was held in Herrsching, Germany in the beginning of June. We attended to see what is going on in the field of satellite based research, what kind of images are available and maybe get some ideas about how to use satellite images in our project. The presentations were mostly in the field of maritime industries, navigation and dredging, but some also focused on ecology. The conference was mainly spent making contacts with the experts of the field and getting a grip on the scale and possibilities of the usage of satellite images in our project.

Written by Jaakko Haapamäki