How do you combined data types (TS/GPS/Level)?
I love your integration of GNSS antenna and prisms pfirmst.
I tried using SALSA before but gave up on it, I lacked the intellectual ability to figure out how to use it properly (I'm too dumb and/or lazy).
I can show you a small job if you like, it's fairly simple. The hardest part is entering covariance matrices from Sinex files.
I use TBC to handle observations and adjust, entering elevations from leveling as control. And I only bring scaled ground points into C3D. I don’t trust it to scale data. Bring it in finished and with no allowance for a setting to move and mess it up!
I'm late to the conversation because I rarely get on here, but great responses. A properly weighted least squares adjustment is your friend. Reminising of doing this before there was easy LSA software from the equipment manufacturers, but Paul Mystric of Canada GeoLab Software was the bomb, I started using it and working with Paul when we were using UNIX based computers before PC's. You had to dig into the equipment specifications for each data source instrument for instrument standard errors, use some logic and experience for observation standard error weighting and play with it. The goal was not to put some global scalar to make the adjustment match the statistical tests like Chi-Square test. And chasing outliers and deleting observations if need be was part of the fund hound hunt of getting the best solution. Usually, we would work with our best known data set such as GPS vectors once that was available and keep adding the other data sets in one at a time. Ah, the good old days, thanks for prompting this old dog's memory, it's not really very good these days but I have moments.
I am teaching a crew now doing this very thing. Base rover rtk network RTK to get started from and robotic total station. This is all in Trimble Access and the qa/qc and LSA will be performed in TBC.
Arrive to site break out the R12i do an observed control point via network RTK. Set base up on said point. I always do RTK and logging as an extra check to send off to opus. It takes no more time. Drive to another great location for the base to be moved to. These do not need to be inter visible they are the best open sky I can find on or off the site. Rtk a point observe control method via base rover. Switch to network RTK observe again same point name. This gives me a Ck later on any rotation as technicaly the direction or azimuth for gps is good within the observation error. Start setting points inter visible where needed for robot locate property corners and any mapping or Topo as time allows. At about the 4 hr mark depending I have usually hit many points once via base and rover depending on site size I may have done another network RTK observation on another point for possible base location. Move the base to the other point set up on it RTK logging. Run the circuit back through all points again including the first base point. Next day or same day the robot can be set up and rounds turned mini traverses cross ties made all in same job file. Like mentioned above you need to keep the law of averages kinda in your head as you might see more error between points that were RTK derived than just a robot relative precision. If Thad a bad shot on a observation this could have you chasing your tail. Just for example let’s say you have a 0.2 vertical error on a bs and you have double checked the hi and target height. I keep moving as I know Trimble accusing using one of the observations and if I used two the odd are it’s half that. I usually check the data daily in TBC I have a list for the next day for crews to re observe at a different time those outliers that raise there head. It’s usually the ones we observe in canopy. But usually even then a third observation via RTK or when you have connected to other points with robot you can disable the bad vector before or other observation before the actual least squares is performed. I do this daily and keep a list as they work through a project. It’s usually only takes a small amount of time and by the time the project is done I have a good idea exactly what to use and not use and the least squares is quickly done and all data has been qa/qc and now ready for drafting and surface contours ready. I usually send the logging files to opus and name them accordingly and this lets me choose the opus or network solution for my primary position. In all honesty there is usually not a nickels difference in most cases the network for rtk is tied to CORS so it’s a sanity check. That’s how it’s done majority of time. When I have my way I do all the boundary corners and control first no mapping. Do least squares and make a new tbc project with the adjusted control. That way daily files for mapping and Topo come in and my screen is not so cluttered. But reality is that is not how bosses want things done so I am flexible and work through it.
I have about 2000 acre boundary coming up where I will use fast static RTK base and rover on and robot. 7 or 8 tracts inside to be all combined vacate the lines. I will work from center out and surrounding my total site via fast static non intervisable primary control. Then use rtk base rover along with robotic to fil in gaps where necessary. We actually have to be creative in setting a good network design as we don’t have sections but very odd irregular shaped properties. As well as finding holes or open areas to set control in. Because of so much canopy. While google earth is awesome it is a different story when you get to a site that was timbered 15 years ago now it’s so thick you can’t see 50 ft in front of you much less get a clear sky. So often it’s on the fly designing the geometry. Sometimes it’s impossible and law of averages as the statistics often don’t show that you have a good position because so many acute angles in observations so a lot of looking at the spreads of multiple observations is a better indicator in those situations and common sense to know you have a good answer that works.
I always tray and picture my site as a wagon wheel with spokes working center to outside the property. Then closing the triangles around and inside the site. I have added NGS CORS data to help strengthen my figure of a site to the base stations that we’re logging and it improves the statistics but the end coordinates didn’t change enough it was all about the geometry for the final results. I try and achieve a tight tie to the NSRS while maintaining more focus to the relative accuracy of the site its seals that’s the boundary side. You can achieve both. And it’s all about for Trimble in having a good naming convention where point 1 is always point one no matter how from where and many times you located it makes it so easy.
I used to do the “adjust control first” - then not use TBC again but now I keep all my data in one VCE file and keep adjusting it since it’ll use total station bscksights and observed angles to other control points plus new control set. I use integrated surveying 98% of the time
Yes. TBC has its issues but it has to be one of the best tools for managing the data on a project that utilizes different sensors like gps robot etc to keep easily updating until final delivery is ready. I wish they would update it more to have more drafting abilit compared to civil 3D and Carlson CAD. But it’s not to bad for me but as I learn more in the other CAD platforms I can see why those who are use to that like cad better for sure. Integrated surveying is so beneficial once people wrap their heads around it.
