Differential Gps (Dgps) - JRC FF50 Instruction Manual

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Differential GPS (DGPS)

The differential GPS comprises a reference station with its position(latitude
and longitude) accurately known, a beacon station for radio broadcasting of
DGPS correction data, and user-owned GPS sensor equipped with a differential
correcting function.
The GPS sensor is used to fix the position of the reference station whose
position is accurately known and to eompare this with the actual reference station
position to get range errors. The range errors are transmitted to the beacon
station as the DGPS correction data and are broadcast from the beacon station to
the user. This DGPS correction data is received by the user-owned beacon
receiver, and is sent to the GPS sensor. The GPS sensor calculates its own
position by adding the correction data to the actual data transmitted from the
satellites.
Compared with the fixed positioning provided by existing GPS sensors, the
DGPS system calculates the position with a very small error not exceeding 10%.
DGPS Syatem
Figure 6-4