A local area augmentation navigation system for determining the location
of an object using differential GPS. The system does not require any
significant power or communication infrastructure. The system includes at
least three reference stations, a master station and a LAAS receiver. The
at least three reference stations are located in close proximity to each
other and at known locations. Each of the reference stations receive a
GPS signal from a GPS constellation and collect and output via a wireless
transceiver the pseudo-range data from the GPS signal. The master station
is positioned in close proximity to the reference stations and receives
the pseudo-range data from the reference stations. The master station
forms a correction message from the pseudo-range data and the known
locations of the reference stations. The master station broadcasts the
correction message within a specified area. The LAAS receiver is
positioned within the specified area and receives the correction message
broadcast by the master station as well as a GPS signal from the GPS
constellation. The LAAS receiver calculates the location of the LAAS
receiver with the correction message and the GPS signal.