EarthExplorerWe will be using an example of an alert on an oil spill of the coast of the Italian island of Corsica. We received an email that told us that there was talk of the oil spill off the coast of Corsica but no images or details available. at that point we went to EarthExplorer (a US Geological Survey web site that allows users free access to search a database of satellite images). In this case, the date was early September 2013, so we had a date range to work around.
The search produced an image in the date range, off the northwest corner of Corsica that looked like it showed an oil slick. EarthExplorer has a viewer but it is only a low-resolution image. There, image was downloaded to our server and loaded into Quantum GIS (an open source software package used to view and annotate Geological Information Systems images). the download was a high-resolution image.
Once the image was loaded into Quantum GIS, it could be viewed in High-Resolution and the slick was visible. Annotations were made to the image with Grass (an open source software package that interfaces with Quantum GIS). The image was then downloaded into Google Earth and posted on the Skytruth.org/Blog with a description of what we found.
So, in the period of a day, thanks to the tip from an unknown person in France, and the luck of having the appropriate satellite image available Skytruth was able to Alert the world of an oil spill that was not being reported by government agencies or other media.
Skytruth needs people to help both in the gathering of information about possible incidents and in searching out and processing of satellite images that are posted in the Alerts. If you think that you would like to take part in these activities click on Get Involved.