How gps works, Dgps, How gps works 4 – Leica Geosystems GPS Basics User Manual

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GPS Basics -1.0.0en

How GPS works

3. How GPS works

There are several different methods for

obtaining a position using GPS. The

method used depends on the accuracy

required by the user and the type of GPS

receiver available. Broadly speaking, the

techniques can be broken down into

three basic classes:

Autonomous Navigation using a single stand-alone receiver. Used by

hikers, ships that are far out at sea and the military. Position Accuracy is

better than 100m for civilian users and about 20m for military users.

Differentially corrected positioning. More commonly known

as DGPS, this gives an accuracy of between 0.5-5m. Used for

inshore marine navigation, GIS data acquisition, precision

farming etc.

Differential Phase position. Gives an accuracy of 0.5-20mm.

Used for many surveying tasks, machine control etc.