GPSrChive Discussion Forum

Hi

I am performing a receiver test where my location is a few meters offset from the actual position. Looking at the diagnostic I can see that my DOP's are below 1 however VDOP is around 4.
Can vertical dilution issue cause the incorrect lat/long position?

Thanks

Basic answer to your question is no.

Vertical precision using GNSS is always less accurate than horizontal position accuracy.

How do you know your receivers actual position?

.kml file as a layer on Google Earth....if that is reliable

That most certainly is not reliable.

Where are you located?

Do you have any benchmarks nearby?

I'm in Gloucestershire, UK.
I can see one nearby on the surveying map.

I suspect the device is not that great as every time I turn the GPS logger on it is away from my "fixed" location by up to 5 m in various directions. Lat/long.

I'm not worried about altitude, I was curious if poor VDOP would affect it.
I'm using Quectel SC200E

I would recommend testing accuracy at that location, averaging multiple samples over many days.

You can also use a GNSS Prediction service to find the best days and times for testing.

See GPSrChive > GNSS > Satellite Prediction