Swami 4000+ GPS - Manual (Page 17)

About GPS
Global Position System (GPS) is a satellite system developed by the U.S. Department of
Defense. GPS consists of 32 satellites that circle the earth and are 11,000 miles away from
the ground. These satellites make two circles of the earth per day and emit signals of ex-
tremely low power which will be received and recorded by 5 ground stations. These ground
stations will use precise time signals to confirm accurate positions of each
satellite. Your GPS receiver can receive signals sent out by these satellites. An accurate
latitude and longitude location can be determined when fixed upon at least 4 satellites.
WAAS (Wide Area Augmentation System) can enhance the precision of GPS. It was
designed by the Federal Aviation Administration and is mainly used to enhance precision
of GPS on an airplane. WAAS has extra ground stations in select positions which can work
together with a master console to improve accuracy of satellite signals and reduce errors to
about 3 yards.
Using Conditions
As Swami 4000+ uses GPS, it is available only in the places that can receive satellite
signals, excluding places indoor or in water.
16 About GPS / Using Conditions