Special Notes; Gps; Dgps - Leica MX400 Operating Instructions Manual

Operator's Manual
receiving equipment, and navigators).
Marine radio beacons operating in the 283.5 to 325.0 KHz fre-
quency range are in widespread use for direction finding in coastal
navigation. Because the beacon system has been in place and
widely used for many years, it provides an effective means for the
transmission of DGPS signals. Depending on their local environ-
ment and power output, their signals may be usable to several
hundred miles. Marine beacons provide an economical means of
obtaining DGPS accuracy for coastal navigators. GPS receivers
with built-in beacon receivers are designed to provide low cost
reception of DGPS corrections broadcast (normally free of charge)
by coastal authorities.

Special Notes

GPS

Never rely solely on any single navigational aid. Always use
whatever information is available, and cross-check information
!
when possible. GPS expected position accuracy is better than 100
meters (95% of the time); but may be up to 300 meters occasion-
ally. The derived speed and course readings may be hampered
accordingly. The GPS system was declared operational in 1994,
however, the system's availability and accuracy are subject to
change at the discretion of the US Department of Defense.

DGPS

This GPS receiver's position accuracy is improved to 5 meters or
better for 95% of the time, subject to the availability, accuracy, and
control of the DGPS correction transmission from the Beacon
!
Station, or other reference station connected at the time of usage.
The differential GPS position is that of the navigator GPS antenna,
and not that of the beacon antenna, if a separate beacon antenna is
in use. In addition, the beacon radio signal which carries the DGPS
corrections may be hampered by weather conditions such as heavy
rain, snow, and thunder storms. The beacon radio signal may also
be interrupted by powerful radio transmitters operating in long
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About GPS Navigation
Version 3.3