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We have been using RTK survey solutions and Total Station survey separately on topos but now wish to combine the two techniques into the same survey, to leverage the strengths of both these solutions.
I'm looking for advice or a start point for investigation on how to accomplish this.
This Content Originally Published by a land surveyor to Land Surveyors United Network
Yes Pat, separate equipment but the data collected combined into one topo survey.
I'll dig through my previous blogs - but I think this very topic was hashed out a few months ago.
Hi Kevin, what does hashed out mean?
?? Hashed out?? - debated, talked about, discussed and more or less resolved
try going back to this discussion topic
Ian, what has made life a bit easier for me in combining RTK and TS field data is to be certain you are using the same control points, best efforts being that you measure to at least three control points prior to stating your survey and by measuring to at least three control points at the end of the survey. If for some reason you are not happy with the measured results, you can run down the errors before collecting a lot of data that has to be adjusted at a later time.This technique can be a quick check to be sure that each type of sensors you are using (GPS or TS) have the same settings/configurations for the project. As you may know, vertical measurements (elevations) are some of the most difficult field measurements to match between RTK vs Total Station are even from a level run.
Thanks for you reply Robert.
The advise you guys are providing has allowed me to understand it's possiable to combine the data.
The reason I'm asking is that although RTK is fast and accurate for our needs, sometimes we can't get onto ajacent properties or are in an urban canyon where GNSS is unavailable. In these circumstances, we would use the Total Station, however in more open survey sites we can complete the survey using RTK alone.
There is an option of Integrated Surveying using a conventional instrument and GNSS. I know you can do this with a Trimble instrument and GNSS. Please see below from Trimble Survey help:
Using an integrated survey (IS) allows you to connect to both a GNSS receiver and a conventional instrument at the same time.
You can perform an integrated survey using Trimble servo total stations and RTK surveys.
The truth is that the two equipment cannot talk to each other but the data each acquired can be married together to give a result. All you need to do is to make sure that the have the same projection. Total station works with the principle of intersection i.e occupy the known to get the unknown. i will advice u use the DGPS to establish the known point (control) to enable the total station to take off and since its a topo, survey try and minimize the no of instrument setup thanks
All other points aside, I'll add (maybe repeat) the following
1) If you are not using a data collector that can run both systems - GPS/RTK and Terrestrial / Total Station equipment, ( unplug the GPS and plug into your TS on the fly) you need to take a hard look at how you are investing in and operating your survey business. That was the final determining factor when I selected my first GPS system back in 1998
2) A Point is a Point - it should not matter if you obtain, occupy or establish a control point via GPS or Total Station if you have the proper procedures in place.
3) Some of us obsess over point quality - its been my experience that more than 95%(?) of any point error falls within standard allowable spec'd tolerances. The other 5% is human operator error ( sometimes called UTS errors) and no data collector mode, GPS setting or Total Station/EDM calibration is going to correct for untrained or under trained field crews and techs.