HDOP values issue

While reading from the gps, HDOP value (in GGA message) sometimes stay the same meanwhile the status changes ( from fix to float or fix to float ) and the lat_accuracy & lng_accuracy (in the EMLID web GUI) also change in wide range (7cm to 5m)
Is this normal ?

and How the lat & lng accuracy are calculated ?
Is there any way to get lat & lng accuracy from the NEMA message ?

HDOP has to do with the geometry of the satellite constellation. Is is not a direct measurement of GPS accuracy.

Thank you, Now i see that hdop isn’t something to know how accurate the position is.
What can i depend on to get the accuracy ??

Hi Ibrahim,

Do you mean what NMEA message you need to get information about accuracy?



You might want to check GST NMEA message.

Thank you very much,
It worked and i got the values from the GST NMEA message,
But it is different from the numbers shown in the web page of the EMLID output
Could you help me with understanding the reason of this difference ?!

Again, Thank you

This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.