RAIM

RAIM stands for Receiver Autonomous Integrity Monitoring. It allows a GNSS receiver to detect and exclude both faulty and fraudulent satellite signals. The Boreas internal GNSS receiver is equipped with RAIM and it is enabled by default.

An improved class of RAIM, Fault Detection and Exclusion (FDE), is used in some GNSS receivers. The objective of FDE is to detect positioning failure and exclude the source of failure; however, it may not identify the specific source. FDE uses a minimum of six satellites to detect and exclude a possible faulty satellite from the navigation solution to ensure that the navigation function remains uninterrupted.

The availability of RAIM and FDE might be slightly lower for mid-latitude operations and slightly higher for equatorial and high-latitude regions because of the nature of the orbits. The availability of RAIM and FDE can be enhanced by using satellites from multiple GNSS constellations or using SBAS satellites as additional ranging sources.