Hemisphere GPS Crescent V100 Series, Руководство пользователя

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Crescent V100 Series User Guide
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Crescent V100 also tracks a differential correction. The Crescent
Crescent V100 uses these corrections to improve its position to less
than 1 meter (1.09 yards). The Crescent V100 has an accuracy of
2.5 meters (2.7 yards) with no differential and 60 centimeters
(23.6 inches) with differential.
There are two main aspects of GPS receiver performance:
• Positioning
• Satellite acquisition quality
When the Crescent V100 is properly positioned the satellites
transmit coded information to the antenna on a specific frequency
that allows the receiver to calculate a range to each satellite. GPS
is essentially a timing system. The ranges are calculated by timing
how long it takes for the GPS signal to reach the GPS antenna. To
calculate the geographic location, the GPS receiver uses a complex
algorithm incorporating satellite locations and ranges to each
satellite. Reception of any four or more of these signals allows a
GPS receiver to compute 3-dimensional coordinates.
Differential Operation
The purpose of differential GPS (DGPS) is to remove the effects of
SA, atmospheric errors, timing errors and satellite orbit errors,
while enhancing system integrity. Autonomous positioning
capabilities of the Crescent V100 will result in positioning
accuracies of 2.5 meters (2.73 yards) (95%). In order to improve
positioning quality to sub-meter levels the Crescent V100 is able to
use differential corrections received through the internal SBAS
demodulator. In addition to these differential services the V110 can
also receive radiobeacon corrections.
For more information on the differential services and the associated
commands, please refer to Hemisphere GPS’ GPS Technical
Reference manual.