I am working on sea surface temperature satellite images and looking for delineating gradients in open source on the basis of temperature. Is there any tool like Cayula and Cornillon front detection tool of ArcGIS
 that may help in this.
The one method that is suggested to me is to use high pass filter and contouring. But in both the cases I am not able to draw a line on a temperature specific front. In high pass filter it is detecting all the edge which I am not interested in and in contours it is interval based.
I'm searching for a tool in QGIS (or any open source) that automatically:
- identifies gradients(fronts) based on temperature,
- draw the line and
- generates shapefile.
Per a commentor's request: the Cayula Cornillon front detection tool automatically detects SST fronts from satellite SST data. The original paper is published here:
Here's an example dataset: https://www.dropbox.com/s/rtxhln299szonb1/may25.csv?dl=0