Hello,
Something I would like to clarify about continous topo survey styles with Trimble GNSS equipment:
A GNSS rover receiver and base station are set to a positioning rate of 20 hz (0.05 second). The base is over a survey marker, the rover mounted on a truck. A centerline of a road is surveyed.
The surveyor sets a survey style to continous topo at an interval of 1 second. Is the data recorded at the 1 second interval the average of the last period of measurements (0-1, 1-2, 2-3, etc.) or the actual position at the very time that the 1 second is reached (1,2,3, etc.)?
Would results differ much if the data was processed in post-processed kinematic mode as opposed to real-time mode (RTK)?
Thank you,
Georges
There shouldn't be any averaging going on using a higher observation rate. In fact, I would recommend that you set your base and rover collection rates to be the same rate (sounds like you would want 1 second), because often manufacturers specify different (worse) accuracy and ppm statistics for collection rates less than once per second. I believe manufacturers are forced to take some time saving shortcuts with their algorithms to make data available this rapidly, which reduces their accuracy.
The biggest difference you will see from post processing will probably be the opportunity to use a different ephemeris than the broadcast one, which would theoretically be better. In reality, I'm not sure you will see much of a difference in short baselines that are typical with RTK type surveys.