A positioning information distribution system for distributing positioning
information through a data network is described. In one embodiment, the
system distributes satellite information from a global positioning system
(GPS). The system includes an information processing station connected to
a data network accessible by wireless communication, a receiving station
including a GPS receiver, and a mobile unit including a GPS receiver and
a wireless receiver. The information processing station collects GPS
satellite information from the receiving station and transmits the
satellite information to the mobile unit using wireless communication.
Alternately, a network of receiving stations are provided. The mobile
unit can obtain the satellite information from the information processing
station for determining its measured position, even when the mobile unit
is roaming in an urban area and is not able to observe the GPS satellites
for the lengthy observation period needed to acquire the satellite
information itself.