Chapter 3
GPS Reception
This chapter covers topics associated with clock location, mounting,
and GPS reception. For additional technical information on external
antennas and cables, and using a surge arrester, see Chapter 7.
Reliable operation requires that the Model 1095A/C with internal
antenna, or external antenna, be placed so that it continuously receives
GPS signals for accurate time keeping. Clock installations without a full
view of the sky may cause lapses in GPS reception with possible loss
of synchronization (lock). If the clock should lose lock for any reason,
information in this chapter should help in system recovery.
The Model 1095A/C achieves its accuracy by comparing the internal
clock signal to the incoming GPS signals. Since the 24 active GPS
satellites are constantly moving across the sky in their orbits, they
move into and out of position for reception. Besides providing time to
the Model 1095A/C, a composite signal from each satellite also gives
information regarding the health of the satellite, so that the GPS receiver
can decide whether to use it for timing purposes.
3.1
Basic Setup
For complete coverage, the Model 1095A/C needs to have a clear view
of the sky from 10 degrees above the horizon to directly overhead for
all points of the compass. Minimal installations, where the antenna is
mounted in a less favorable location, may work however reception may
be somewhat limited during certain hours of the day.
