Rough weather caused by clouds and storms is easy for pilots and ground crews to spot and avoid when planning a flight route. But even perfectly clear skies can be full of invisible pockets of CAT—or clear-air turbulence—that are now easier to spot and predict thanks to a European laser-based detection system known as DELICAT.

Developed by the DLR German Aerospace Center, DELICAT, or demonstration of LIDAR based clear air turbulence detection, is a custom system installed on planes that blasts short-wave ultraviolet laser radiation ahead of the aircraft. The backscatter from that blast is measured and used to detect fluctuations in the density of nitrogen and oxygen which is what causes the invisible turbulence.

Ideally the system will give pilots plenty of advanced notice so they can avoid the invisible turbulence altogether. But at the least it will give them a few moments to flip on the fasten seatbelt sign to ensure that passengers and flight crew aren't unexpectedly jostled about. [DLR German Aerospace Center via Gizmag]