A server provides GPS aiding data to mobile GPS receivers are provided with an
enclosed environment (e.g., within a large building) where the received GPS signal
is likely to be weak or suffer multipath signal interference. The server receives
GPS signals from one or more antennas within the enclosed environment and measures
the multipath error in the vicinity of each antenna. Using the multipath error
data for various satellite positions at various times, the server creates a delay
model for the enclosed environment to generate GPS aiding data for the mobile GPS
receivers. A generic delay model can be created that is applicable to similarly
constructed buildings.
