High Quality Content by WIKIPEDIA articles! The GPS aided geo augmented navigation or GPS and geo-augmented navigation system (GAGAN) is a planned implementation of a regional satellite-based augmentation system (SBAS) by the Indian government. It is a system to improve the accuracy of a GNSS receiver by providing reference signals. The AAI’s efforts towards implementation of operational SBAS can be viewed as the first step towards introduction of modern communication, navigation, surveillance/Air Traffic Management system over Indian airspace.