NavCom SF-3050 Rev.A - Manual (Page 158)

SF-3050 User Guide – Rev A
Glossary-156
surface closely, so GPS altitude measurements can
contain a large vertical error component.
Conventionally surveyed positions usually reference a
geoid, which has an undulating surface and
approximates the earth’s surface more closely to
e is
Band carrier
smit satellite
ented Navigation)
stem that provides a set of
built by the
mean sea level over the entire surface
onventionally surveyed positions
ngs can
een the
minimize altitude errors.
epoch literally a period of time. This period of tim
defined by the length of the said period.
G1 carrier frequency the primary L-
used by GLONASS satellites to tran
data. The frequency is 1603.00MHz.
G2 carrier frequency the secondary L-Band carrier
used by GLONASS satellites to transmit satellite
data. The frequency is 1247.00MHz.
GAGAN (GPS Aided Geo Augm
an Indian satellite sy
corrections for the GPS satellites, which are valid for
the Indian region. They incorporate satellite orbit and
clock corrections.
Galileo a GNSS system currently being
European Union (EU) and the European Space
Agency (ESA). Galileo uses the same concepts for
positioning as GPS.
geoid the gravity-equipotential surface that best
approximates
of the earth. The surface of a geoid is too irregular to
use for GPS readings, which are measured relative to
an ellipsoid. C
reference a geoid. More accurate GPS readi
be obtained by calculating the distance betw
geoid and ellipsoid at each position and subtracting
this from the GPS altitude measurement.
GIS (Geographical Information Systems) a
computer system capable of assembling, storing,
manipulating, updating, analyzing and displaying