Air travel is a very safe way to travel long distances in a short time, but it is often subjected to turbulence, something that can range from a minor annoyance to a terrifying experience, particularly if it causes the plane to buck and jerk. Detecting it is a science still in the works, and amongst the possibilities is one proposal suggesting the use of common GPS.
An atmospheric scientist with the National Oceanic and Atmospheric Administration, Seth Gutman, along with a team of researchers has proposed one method to detect turbulence and alert pilots before they hit it. With the system, GPS is utilized as a sort of real-time sensor for monitoring air conditions.
This is made possible by the refraction and delays that GPS signals experience when exposed to watch vapor in the atmosphere. That delay information is used in weather models, but typically averaged out over 30 mins. Under the proposed detection system, that would be reduced to "about a second".
High-accuracy GPS receivers would be needed, of which thousands are said to be located around the US for government use. Each could potentially be used to detect turbulence in its own field, and the information could be ported into a warning system that gives pilots a heads up.