Gain
A measure of amplification expressed in dB.
GE Americon
This is a large U.S. corporation providing satellite systems for domestic communications. Has ownership in some international satellites.
Geostationary
Refers to a geosynchronous satellite angle with zero inclination. so the satellite appears to hover over one spot on the earth's equator.
Geostationary Transfer Orbit
This orbit is in the equatorial plane. This type of orbit has an elliptical form, with a perigee at 200 km and an apogee at 35870 km.
Geosynchronous
The Clarke circular orbit above the equator. For a planet the size and mass of the earth, this point is 22,237 miles above the surface.
Gigahertz (GHz)
One billion cycles per second. Signals operating above 3 Gigahertz are known as microwaves. above 30 GHz they are know as millimeter waves. As one moves above the millimeter waves signals begin to take on the characteristics of Iightwaves.
Global Beam
An antenna down-link pattern used by the Intelsat satellites, which effectively covers one-third of the globe. Global beams are aimed at the center of the Atlantic, Pacific and Indian Oceans by the respective Intelsat satellites, enabling all nations on each side of the ocean to receive the signal. Because they transmit to such a wide area, global beam transponders have significantly lower EIRP outputs at the surface of the Earth as compared to a US domestic satellite system which covers just the continental United States. Therefore, earth stations receiving global beam signals need antennas much larger in size (typically 10 meters and above (i.e.30 feet and up).
Gregorian Dual-reflector antenna system employing a paraboloidal main reflector and a concave ellipsoidal subreflector.
Globalstar
A mobile satellite system that deployes a network of 48 satellites to create a global voice and data service. This system is backed by Qualcomm, Loral, and Alcatel.
G/T
A figure of merit of an antenna and low noise amplifier combination expressed in dB. "G" is the net gain of the system and "T" is the noise temperature of the system. The higher the number, the better the system.
Guard Channel
Television channels are separated in the frequency spectrum by spacing them several megahertz apart. This unused space serves to prevent the adjacent television channels from interfering with each other.
sGHz Gigahertz
GNSS Global navigation satellite system G/T Gain to noise temperature
Ku Kurtz-Under Band
LNB Low Noise Block downconverter
pps pulse per second
R&D Research and development
Rx Receive
SDR Software-defined radio
SOR Statement of Requirement
Tx Transmit