SBAS Integrity is outlined by ICAO SARPs Appendix 10 and refers to the level of trust of the satellite navigation information received and the computed position. Integrity of a navigation system includes the ability to provide timely warnings if the information broadcast or that is computed could potentially create hazards.
The ICAO SARPS specification for SBAS requires the system to detect errors in the GNSS or GEO network and notify users within a very small time constraint. Certifying that SBAS is safe for instrument flight rules (IFR) requires proving there is only an extremely small probability that an error exceeding the requirements for accuracy will go undetected. Specifically, the probability is less than 1�10-7, and is equal to no more than 3 seconds of bad data per year.
For safety reasons, within the specified time constraint, SBAS can do one of two actions:
I. Provide a correction to the information that is detected as misleading. If SBAS is able to correct misleading information within the time constraint, there is no lapse in system integrity.
II. Notify the user not to use the information.