Detail

FUZZYUPWELL – Fuzzy Modelling Tool for Upwelling Recognition from SST Satellite Images

In our previous work we applied fuzzy clustering to the problem of identification of upwelling areas
from Sea Surface Temperature (SST) images, and showed that the approach was promising. However,
the approach required a user-supplied information for annotation of the upwelling area on the map in
order to fine-tune parameters of the method.
In this paper, we modify the method to apply it in a fully automated manner without any prespecified
expert knowledge. We describe a computational system, FuzzyUPWELL, that provides a
framework needed for a totally unsupervised segmentation and delimitation of upwelling areas on SST
images. The FuzzyUPWELL system integrates an unsupervised fuzzy clustering algorithm, a threshold
procedure combining a set of features extracted from clusters to determine the upwelling fronts, a
mechanism to delimitate the upwelling areas by fuzzy boundaries defined from measures of
classification uncertainty, and a Graphical User Interface (GUI).
The system has been successfully applied to a collection of 113 images obtained at the coastal ocean
of Portugal during the upwelling seasons of 1998 and 1999. The collection covers much diverse
upwelling situations. The system is shown to be robust to false positives when analysing its response
on SST images without upwelling.