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Pragmatic way to determine if cm level accuracy is reached
Alf Kuchenbuch asked 4 years ago
Dear All,
My base is running all the time. When I startup my rover, its accuracy is poor until it picks up the correction signal from base and its own satellites. After about 2min cm level accuracy is reached. What is a good indicator that my system has reached cm level accuracy? Is it PDOP<=1 or HDOP<= 0.6? Or is there a better way?
Thanks in advance,
Alf
My base is running all the time. When I startup my rover, its accuracy is poor until it picks up the correction signal from base and its own satellites. After about 2min cm level accuracy is reached. What is a good indicator that my system has reached cm level accuracy? Is it PDOP<=1 or HDOP<= 0.6? Or is there a better way?
Thanks in advance,
Alf
2 Answers
django122 answered 4 years ago
Hello,
do you mean field 6,7,8 of the $GP message?
Matthias
do you mean field 6,7,8 of the $GP message?
Matthias
Alf KuchenbuchHi Matthias,
I use NMEA GxGST (GNSS Pseudorange Error Statistics) to see the standard deviations of latitude, longitude and altitude.
And I use NMEA GxGGA (Global Positioning System Fix Data) to see the field “Status”. If Status is 4, it’s Fixed RTK, which apparently is a good indicator to sub 2cm accuracy.
Regards,
Alf
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Staff replied 4 years ago
Best is to use Fix Type indicator: when indicator is RTK FIXED this usually means you have sub 2-cm accuracy.
Alternatively you can read accuracy estimate value, available in GST message.
replied 4 years ago
Great answer! That’s what I was looking for. Thanks!