Leica Geosystems GPS Basics - Manual (Page 53)

53
GPS Basics -1.0.0en Glossary
GPS time
A continuous time system based on the
Coordinated Universal Time (UTC) from
6th January 1980.
Greenwich mean time (GMT)
The mean solar time of the meridian of
Greenwich. Used as the prime basis of
standard time throughout the world.
Great circle course
Term used in navigation. Shortest
connection between two points.
Graticule
A plane grid representing the lines of
Latitude and Longitude of an ellipsoid.
Gravitational constant
The proportionality constant in Newton’s
Law of gravitation.
G = 6.672 * 10 -11 m 3 s -2 kg -1
Inclination
The angle between the orbital plane of
an object and some reference plane
(e.g., equatorial plane).
Integer bias term
See Ambiguity
Ionospheric Delay
A wave propagating through the iono-
sphere (which is a non-homogeneous
and dispersive medium) experiences
delay. Phase delay depends on electron
content and affects carrier signals.
Group delay depends on dispersion in
the ionosphere as well, and affects
signal modulation (codes). The phase
and group delay are of the same magni-
tude but opposite sign.
Kinematic positioning
Determination of a time series of sets of
coordinates for a moving receiver, each
set of coordinates being determined
from a single data sample, and usually
computed in real time.
Keplerian orbital elements
Allow description of any astronomical
orbit:
a: semimajor axis
e: eccentricity
w: argument of perigee
W: right ascension of ascend
ing node
i: inclination
n: true anomaly
Lambert Projection
A conformal conic map projection that
projects an ellipsoid onto a plane
surface by placing a cone over the
sphere.
Latitude
The angle between the ellipsoidal
normal and the equatorial plane.
Latitude is zero on the equator and 90°
at the poles.