Sokkia GSR2700 ISX, Operation Manual

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Glossary
GSR2700 ISX Operations Manual 83
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GLONASS—
(GLObal NAvigation Satellite System-GLObalnaya
NAvigatsionnaya Sputnikovaya Sistema) A satellite-based radio
navigation system launched in 1982 and run by the Russian Ministry
of Defense. Similar to the global positioning system (GPS) in the U.S.,
GLONASS permits 3D positioning anywhere on earth; however,
typically it is used as an augmentation alongside the GPS system. The
current GLONASS constellation includes less than 20 satellites, each
traveling in a circular orbit, 19,140 kilometers above the Earth, in
three circular planes. The satellites are positioned so that four are
observable nearly 100 percent of the time from any point on Earth.
GNSS—
Global Navigation Satellite Systems. The collective of
current and proposed satellite navigation systems, including GPS,
GLONASS, and Galileo.
GPRS—
General Packet Radio Service. Technology that allows
mobile phones to be used for sending and receiving data over an
Internet Protocol (IP) based network.
GPS—
Global Positioning System. A radio navigation system owned
and operated by the United States Department of Defense consisting
of 24 GPS satellites in orbit at 20,200 km (10,600 miles) above the
earth. GPS signals are freely accessible for civil applications allowing
land, sea, and airborne users to determine their exact location,
velocity, and time 24 hours a day, in all weather conditions, anywhere
in the world. The satellites are spaced in six orbital planes so that
from any point on earth, four satellites will be above the horizon
allowing any GPS receiver to "triangulates" its own position by
getting bearings from three of the four satellites. The result is
provided in the form of a geographic position - longitude and
latitude - with varying accuracies depending on the GPS positioning
mode.
GPS Time—
The time system upon which GPS is based. GPS time is
an atomic time system and is related to International Atomic Time in
the following manner: International Atomic Time (IAT) = GPS +
19.000 sec. The IAT and Universal Time Coordinated (UTC) are
closely related. The difference is that UTC contains leap seconds to
adjust for changes in the Earth’s rotation. See
UTC .