SME
Surveying · Problem type
GNSS error sources
Use this for “Is ionospheric delay a satellite error, a signal-path error or a receiver error?”
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Where does each GNSS range error come from?
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Follow the signal: it leaves the satellite, crosses the atmosphere, then is timed by the receiver.
Assumptions
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Every GNSS range error starts at the satellite, along the signal’s path, or in the receiver.
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Differential GNSS and RTK cancel the satellite and most path errors shared by nearby receivers.
Topic check
See what you know: 5 questions on this topic
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Related lessons
GNSS
Main lesson
Range from signal travel time
Use this for “A GNSS signal takes 0.0723 s to arrive. How far is the satellite, and what pseudorange does a receiver clock 1 μs off measure?”
Position error from DOP
Use this for “PDOP is 2.1 and each range has a 3 m error. What position error should you expect?”