Magellan GPS PROMARK X, User Manual

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WARNINGS
A measure of knowledge by the user is required for proper and safe use of the
Magellan GPS ProMARK X™ and GPS ProMARK X-CM™. READ THE
USER GUIDE AND WARRANTY COMPLETELY.
Assess the Accuracy Required
The ProMARK X is generally capable of better than 12 meters (RMS) horizon-
tal accuracy in autonomous operation and better than 3 meters (RMS) horizon-
tal in differential operation — with a little averaging. While this makes it a
remarkable tool for some third-order surveys and for marking and relocating
geographical sites, the product is not intended as a replacement for the
intstrumentation needed for first-order surveys.
Use Good Judgement
This product is an excellent navigation aid, but it does not replace the need for
careful orienteering and good judgement. Never rely solely on one device for
navigating.
Use Care to Avoid Inaccuracies
The Global Position System (GPS) is operated by the U.S. Government, which
is solely responsible for the accuracy and the maintenance of GPS. Certain
conditions can make the system less accurate.
Accuracy can also be affected by poor satellite geometry. WHEN THE ACCU-
RACY WARNING APPEARS ON THE SCREEN, USE THIS DATA WITH
EXTREME CAUTION.
THE GLOBAL POSITION SYSTEM IS A DoD SYSTEM. The government can
make changes to the system that could affect the performance of GPS receiv-
ers.
WARNING
The accuracy of position fixes can be affected by the periodic adjust-
ments to GPS satellites by the U.S. Government and is subject to
changes in accordance with the Department of Defense Civil GPS user
policy and the Federal Radionavigation Plan.
Use Differential Judiciously
While differential and carrier phase can completely remove the effects of
government degradation of the GPS signal (selective availability), this process
assumes identically matched data sets. Prior to using differential or carrier
phase, the user must have a thorough understanding of datums and the theory
behind the differential process.