The case of the lost Malaysian Airlines plane is tragic for all those involved.

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, and 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?