GNSS operations challenges

Satellite operation requires special knowledge, qualifications, and practical hands-on experience gained through extensive training in a very realistic simulation environment. While communication satellites can be monitored at 24/7 basis Earth Observation satellites have limited visibility from the station so that challenges such as working under pressure during short contact times and in-advance planning of the tasks have to be met. Similarly also the operation of navigation satellite constellations requires special focus on the mission-specific operational challenges, for example managing a fleet of satellites. This paper focuses on the specific challenges of operating navigation satellite constellations.