Topcon HiPER GD, Руководство оператора

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Principles of Operation
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Principles of Operation
Surveying with the right GPS receiver can provide users accurate
and precise positioning, a requirement for any surveying project.
This section gives an overview of GPS and receiver functions to
help you understand and apply GPS principles, allowing you to get
the most out of your receiver.
GPS Overview
The Global Positioning System (GPS), run by the United States
Department of Defense (DoD), is a network of up to 29
satellites (at time of printing) orbiting the earth every 12 hours.
The Global Navigation Satellite System (GLONASS), is the
Russian Federation Ministry of Defense counterpart to GPS. At
any one time, with a standard 15 degree mask angle, up to 10 or
12 GPS satellites are visible from any point on earth. When a
receiver can also track GLONASS satellites, between 10 and 16
satellites are visible.
The GPS and GLONASS network has three components:
• Space – GPS and GLONASS satellites orbiting
approximately 12,000 nautical miles above Earth and are
equipped with a clock and radio. These satellites broadcast
digital information (ephemerides, almanacs, time frequency
corrections, etc.).
• User – The community and military that use GPS/
GLONASS receivers and the corresponding satellites to
calculate positions.
• Control – Ground stations located around the Earth that
upload data, including clock corrections and new
ephemerides (satellite positions as a function of time), to
ensure the satellites transmit data properly.
GPS receivers use ephemeris and almanac data to calculate
accurate positions, and the positions of your survey points.