In one aspect, a method for determining a predicted performance of a navigation augmentation system includes determining a normal performance of the navigation augmentation system and determining a predicted performance of the navigation augmentation system based on determining the normal performance.In another aspect, a system for determining a predicted performance of a navigation augmentation system includes a long-term monitor for determining a normal performance of the navigation augmentation system and a short-term monitor for determining a predicted performance of the navigation augmentation system based on the normal performance of the navigation augmentation system.