The case of the lost Malaysian Airlines plane is tragic for all those involved - http://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370.

In the case of such a plane lost over the ocean, hypothetically, (and described very simplistically), it would seem that the fastest way to search for wreckage would be to define an area to be searched, wait for the latest satellite images for that area at high-resolution to be available (given appropriate positioning and programming of the satellites), then search the captured imagery for deviations from ocean blue. Presumably this could be done reasonably quickly by a computer, assuming that satellite imagery is taken after a suspected crash, and exceptions (e.g. spots of white amongst the blue) are able to be verified by a human.

Does such a system exist? Are imaging satellites able to be configured to take such imagery on demand over a large area? And do such batch-image processing systems exist for this purpose?