Comparision of the probability of visibility of new planned mobile satellite systems (M-star, Celestri, SkyBridge)

In the years 1996 and 1997 some new mobile satellite systems for communication services with high data rates have been proposed. The most important systems are M-Star, Celestri, and SkyBridge. The probability of visibility is presented for these new planned mobile satellite systems for low Earth orbits (LEO). The performance of a satellite system is primarily dependent on the probability of visibility and the elevation limit. The probability of visibility should be 100% over a wide range of elevation limit in order to provide continual service. This papers presents the probability of visibility and the elevation limit for different latitudes and compares the three systems. Additionally, the three systems are compared with the changed Teledesic systems, which constellation was reduced to 288 satellites in the year 1997