NavCom SF-2050 Rev.D - Manual (Page 53)

SF-2050 User Guide - Rev. D
Glossary
.yym files see meteorological files (where yy = two digit
year data was collected).
.yyn files see navigation files (where yy = two digit year
data was collected).
.yyo files see observation files (where yy = two digit
year data was collected).
almanac files an almanac file contains orbit
information, clock corrections, and atmospheric delay
parameters for all satellites tracked. It is transmitted to a
receiver from a satellite and is used by mission planning
software.
alt see
altitude .
altitude vertical distance above the
ellipsoid or geoid . It
is always stored as height above ellipsoid in the GPS
receiver but can be displayed as height above ellipsoid
(HAE) or height above mean sea level ( MSL ).
antenna phase center (APC) The point in an antenna
where the
GPS signal from the satellites is received. The
height above ground of the APC must be measured
accurately to ensure accurate
GPS readings. The APC
height can be calculated by adding the height to an
easily measured point, such as the base of the antenna
mount, to the known distance between this point and
the APC.
APC see
antenna phase center or phase center .
Glossary-51