Topcon HiPer II, Руководство оператора

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Static Surveying for Base Stations
P/N 7010-0982
4-7
Static Surveying for Base
Stations
Static surveying is the classic survey method, well suited for all kinds
of baselines (short, medium, long). At least two receiver antennas,
plumbed over survey marks, simultaneously collect raw data at each
end of a baseline during a certain period of time. These two receivers
track four or more common satellites, have a common data logging
rate (5–30 seconds), and the same elevation mask angles. The length
of the observation sessions can vary from a few minutes to several
hours. The optimal observation session length depends on the
surveyor’s experience as well as the following factors:
• The length of the baseline measured
• The number of satellites in view
• The satellite geometry (DOP)
• The antenna’s location
• The ionospheric activity level
• The types of receivers used
• The accuracy requirements
• The necessity of resolving carrier phase ambiguities
Generally, single-frequency receivers are used for baselines whose
lengths do not exceed 10 kilometers (approximately 6 miles). For
baselines of 10 kilometers or greater, use of dual-frequency receivers
is recommended.
Dual-frequency receivers have two major benefits. First, dual-
frequency receivers can estimate and remove almost all ionospheric
effect from the code and carrier phase measurements, providing much
greater accuracy than single-frequency receivers over long baselines
or during ionospheric storms. Secondly, dual-frequency receivers
need less observation time to reach the required accuracy.
After the survey completes, data the receivers collect can be
downloaded onto a computer and processed using post-processing
software.
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