ACO-2200 User Guide (v5.0)
Glossary • 41
Glossary
The following terms are used throughout this guide:
• “
Almanac
” refers to a set of parameters included in the GPS satellite navigation message that a receiver uses to
predict the approximate location of a satellite. The almanac contains information about all of the satellites in the
constellation.
• “
CW signals
” refers to continuous wave signals.
• “
Ephemeris
” is a description of the path of a celestial body indexed by time. The navigation message from each
GPS satellite includes a predicted ephemeris for the orbit of that satellite valid for the current hour. The
ephemeris is repeated every 30 seconds and is in the form of a set of 16 Keplerian-like parameters with
corrections that account for the perturbations to the orbit caused by the earth’s gravitational field and other
forces.
• “
Epoch
” is an instant of time (or a date) from which values of data are referenced. Note: an Era is the period of
time between successive epochs.
• “
GLONASS
” refers to the Global Navigation Satellite System.
• “
GPS
” refers to global positioning system.
• “
Operator
” and “
User
” refer to the person who uses ACO-2200.
• “
RF interference
” refers to radio frequency interference
• “
System
” and “
Video system
” refer to the mix of interconnected production and terminal equipment in your
environment.
• “
UTC
” refers to Co-ordinated Universal Time. The time scale based on the atomic second but occasionally
corrected, by the insertion of leap seconds, to keep it approximately synchronized with Earth’s rotation. The leap
second adjustments keep UTC within 0.9 seconds UTI1.
