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2: GPS Overview
GPS Overview
This chapter describes the various modes of operation and features
of your Crescent A100 receiver and internal sensors.
For your convenience, both the GPS and differential correction of
the Crescent A100 are pre-configured. The receiver will work out of
the box, and for most applications, little user set up is necessary.
When powered for the first time, the Crescent A100 will perform a
“cold start,” which involves acquiring the available GPS satellites
in view and the SBAS differential service.
GPS Operation
The GPS engine is always operating, regardless of the DGPS mode
of operation. The following sections describe the general operation
of the Crescent A100’s internal GPS engine.
Automatic Tracking -
The GPS engine within the Crescent A100 automatically searches
for GPS satellites, acquires the signals and manages the navigation
information required for positioning and tracking. This is a hands-
free mode of operation.
Receiver Performance -
The Crescent A100 works by finding four or more GPS satellites in
the visible sky and uses the information those satellites provide to
compute an appropriate position (typically within
2-3 meters). Since there is some error in the GPS data calculations,
the Crescent A100 also tracks a differential correction. The Crescent
A100 uses these corrections to improve its position to less than 1
meter (3 feet) (see
Table B-5: GPS sensor specifications in the appendix).
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Summary of Contents for Crescent A100
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