Final answer:
For Receiver Autonomous Integrity Monitoring (RAIM), at least five satellites are required, and six are needed to identify and exclude a faulty one. Fault Detection and Exclusion (FDE) requires a minimum of six satellites but operates more robustly with seven for increased redundancy and improved navigation integrity.
Step-by-step explanation:
Receiver Autonomous Integrity Monitoring (RAIM) is a technology used to verify the reliability and accuracy of the signals received from the Global Positioning System (GPS). For RAIM to function, a minimum of five satellites is typically required. This allows the receiver to determine a position solution with one satellite as a check. However, to identify and exclude a faulty satellite, a total of six satellites would be necessary.
Fault Detection and Exclusion (FDE) is an advanced form of RAIM that not only detects a faulty satellite signal but also excludes it from the position calculation. To effectively perform FDE, at least six satellites are required, but ideally, seven would provide an even more robust operation. With six satellites, it is possible to identify a faulty signal and exclude it, but with seven, there is additional redundancy which improves the integrity of the navigation solution.