Hemisphere GPS LiteStar II Air, User Manual

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LiteStar II Air User Guide
93
DGPS O
PTIONS
Differential GPS (DGPS) is regular GPS with an additional
correction signal added. This signal, called “Differential Correction”,
allows civilian users of GPS to achieve far greater accuracy than
the GPS signal alone is able to provide.
DGPS uses a reference station at a known point (also called a base
station) to calculate and correct bias errors. The reference station
computes corrections for each satellite signal and broadcasts these
corrections to the remote, or field, GPS receiver. The remote
receiver then applies the corrections to each satellite used to
compute its fix.
The type of DGPS receiver you purchase with LiteStar II Air plays
an important role in the overall performance of the product.
Because the receiver communicates with the Lightbar and
controller, you may want to check the DGPS menu to:
• check the status of the DGPS being used by the receiver
• check the differential source
• swap SLX Apps (switch receivers)
• use e-Dif as the differential source
• check the port setup
• set the local time
Please see “Chapter 1: About LiteStar II Air, Understanding Your
GPS Data” for an overview of GPS.
LiteStar II Air.book Page 93 Thursday, June 7, 2007 4:02 PM