iGage iG4, Руководство пользователя

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This class-1 elevation bench mark with measured gravity is unfortunately in a location that is no
longer suitable for GPS observations. It was set prior to the construction of the powerline. This is a
BAD location.
You should avoid locations that are under high voltage transmission lines and have large steel
towers directly to the south.
Smaller power poles and lines are also unacceptable, especially if they are south of the occupation
site:
#9 Optimizing Occupations in the Real-World
Receiver Placement
In North America, the most important sky is to the East, South and West (because there are never
any GPS satellites directly north.) So, if you are setting up in a field that is surrounded by large trees,
locations in the middle of the North side of the open area are preferable because the southern sky
effectively opens up:
Longer Observations
OPUS-RS is especially vulnerable to bad sites. If you think a site may have problems, try to collect
over two hours of data so that you will have the option of using OPUS-Static. You can always trim
the 2-hour observation file and also submit it as a Rapid Static job in addition to the Static job.
A six-hour occupation may return great results at a site where 2-hour occupations fail. More-time in
adverse locations is always better.