GPS Quality Control - Double Occupations

[HughWyn-Harris]

As collector has started to support high-accuracy receivers it would be good to have the ability to follow good survey practise for GPS measurements. 

It would be good if we had to measure a point twice (say 20mins between each set of measurements) we could have the option of another set of measurements which would be used to calculate a weighted average position for the point using the two sets of measurements. This could also flag any error in a measurement if the 2 measurements did not agree within a certain limit.

The second measurement on the point is to obtain an independent fix by having different satellites in a different constellation.

[RobertBorchert]

I don't think a lot of users are going to want to GPS a location a second time 20 minutes later in the hopes of increasing accuracy.

I think your better option is to purchase a better quality GPS

Often people will use their phones or the GPS unit they purchased at a Fleet Farm and find out they are not terribly accurate.

[HughWyn-Harris]

Hi Robert,

Yes you are right, this probably would not be useful for users using lower accuracy GPS units.

However users chasing centimetre accuracies will know the importance of following good survey practise to ensure their measurements have the appropriate checks therefore confirming the reliability of their data.  

I know users that have better quality GPS would like to measure survey control a 2nd time so it adds redundancy to their data-sets and confirms they are working in terms of the correct coordinate system. RTK GNSS observations on control marks are measured at least twice with a 20 – 30 minutes interval between observations as to check against ionospheric & tropospheric delay, multipath and receiver noise.