Using a Moderate Ionospheric Storm Detector to Improve WAAS Availability

The Wide Area Augmentation System (WAAS) broadcasts information that allows users to bound the positioning error that arises from ionospheric delay of signals emitted by Global Positioning System satellites. A critical objective of WAAS is to make ionospheric grid delays (IGDs) and grid ionospheric vertical errors (GIVEs) available to users as often as possible.