Thanks for the replies.
I'm still reading, still learning - same as any other day.
I had thought I'd be able to set the data collector up in a mapping plane, proper zone, datum, geoid, etc and run GNSS points on the targets, AND THEN use the total station for the targets that I can't get proper satellite views on - all with the mapping projection. So basically using the total station in "grid" and keeping everything relative.
I tried this on another job recently and the data collector would not let me take a backsight. Wouldn't do it. My chief had done a site calibration prior (which i highly disagreed with at the time) and the data collector "protected" the control points, and no amount of manipulation was allowed to any of the data afterwards. I couldn't undo it per se. Couldn't make typical elevation, rotation, translation adjustments. And no backsights, etc etc. But I think the solution is to not calibrate this time, which I wouldn't anyway at all. That has its place and I have no idea why that was chosen.
But this time my plan was to collect the points GNSS, then use the TS in that same mapping plane to transfer SPC to the "tough" targets, so to speak, and handle it myself.
For reference and any haters, this is mountains, canyons, 45 acre site. ONe target is a mile hike on top of the only flat spot on the east side, and it's opposing target location is on a road in a canyon. 600-700' elevation difference between them. So it's been a challenging job to plan up and try to execute. We have to get creative on every target with the budget.
Curious. What equipment or more particularly which DC software are you using?
For those that use DC software that can utilize switching between BOTH GNSS and Total Station prisms on the fly, I would assume all of this is handled automatically? Do you have to enter the combined scale factor at the start of the project for the region (or custom scale factor) or does it know automatically depending on your State Plane CS chosen?
An LDP for that type of site would be simple to construct in Trimble, if that's what you're using.
Put the surface at the elevation mean of the site, put the central meridian near the east-west center and then you never need to think about the Total station again, at those elevations you might be looking at 20ppm at most or .02'/1000'.
I don't understand what locking away the control points would mean, but I suspect you could enter another point on top of each control point and use those.
We're using a Trimble S6 instrument, and the SurveyPro software on a Ranger 3 collector.
On the office side, there's zero support. They use Autocad and civil3d only.
As for "locking" the controls points..When my chief did a calibration on another job with the Trimble R10, it pairs a ground point with a GNSS control point and "protects" them afterward from any sort of manipulation. I can't rotate or transform anything in the collector afterwards. Can't set up and backsight on them with the total station, etc etc.
Even after I try to move on and do something else job-related. It's like a permanent fixture at that point.
So I pulled the coordinates I needed, put them in a new job, and went on topo'ing to get the job done.
This time around my goal was to start it off right, know the processes beforehand, etc etc. Have an actual plan.
I'm taking the reigns because I just was not happy with the workflow and the results last time.
I'm also studying/reading every day to answer question
If the points they are locking are in civil3d you can unlock them, if you wish. I saw on another post you go to UMaine. I have a MS in Data Science from there are you in Maine or out of state studying online?
oh ok, I didn't know that about civil3d.
MS in Data Science- impressive. I just started at UMaine online going for the Surveying/Engineering Technology bachelor's degree - I live and work in California for the time being. I brought in a an associates and have about halfway to go yet.
I am slated to take the Carlson/civil3d course this fall, so I am hoping to learn more about field to office processes.
It depends on your data collector. Trimble Access manages your observations when started with GNSS observations whether it’s GNSS or total station or both because when starting with GNSS, points are stored as latitude and longitude- nit coordinates. I’m not sure how survey pro handles data.
In recent years I've done time with Access running on a TSC3 and a TSC7, Survey Pro on a TSC3, Magnet on a Tesla and an FC5000, and Captivate on a CS20. I also had a day with SurvCE on a I-dont-know -what. Every one of those will run both GPS and TS. Any dc bought in the last 10 years - and kept anywhere near updated - that can't run both has got to be pretty obscure.
Take any courses you can from knud hermansen.
Out of all of those... for the most part, which did you like best right off the bat? I use MicroSurvey FieldGenius (Windows tablets / Android still WIP) with Leica RTS's and Emlid receivers.
Trimble seems the cleanest overall... Captivate is nice too. Hate SurveyPro and SurvCE/SurvPC.
But yes, depends on your equipment... i.e. Trimble equipment with Trimble Access etc.
This Survey Pro tutorial says if you configure your job to state plane the GNSS and TS observations are scaled to grid. Easy Peasy. Trust but verify. You should disagree with calibrating a state plane grid job. The purpose of calibration is to determine a scale which is already programmed. If something isn't fitting there are other issues.
"Out of all of those… for the most part, which did you like best right off the bat?"
In the long run I Iiked Access best and Survey Pro least, but the gap between best and least is pretty narrow. Right off the bat - Survey Pro was probably the easiest learning curve.
I'm currently working with Captivate. Circumstances are such that I probably will be for the duration of my career. I'm comfortable with that.
But I only mention those softwares I've used in the recent past. Those that are still an option in more or less the form they were in when I used them. My experience with dc software goes back to SMI and TDS running on HP48s in the mid 90's.
If you haven't already done so, call the photogrammetrist or lidar team and discuss your issues with them and ask about the accuracy capabilities of the equipment they'll be using. Their standards, ASPRS Vol 1 or 2, require triple on double accuracy (RMSE or 67% confidence level) of the control/check points. If their deliverable is a 2' contour interval topo, you'd be hard pressed to find somewhere in America where a photo panel could be observed from the air but a R12i or Carlson BRx7 or similar base/rover setup couldn't obtain the required accuracy. An RTK base/rover kit with twin R12i receivers, data collector, poles etc. is $375/day at Duncan-Parnell: "https://www.duncan-parnell.com/geospatial-equipment-for-rent".
Any solution to your problem that doesn't involve ground to grid conversion will be the preferred solution. A conversation with the photogrammetrist may reveal that you could have a bit more uncertainty in horizontal positions on a couple of points, which may allow you to quickly run levels while getting a good enough horizontal shot with direct GNSS occupation. It's likely that some of your shots will be held as fixed control acting as a sort of H & Z anchor, while others are simple checks against major errors and might have an acceptable error range of a quarter of a foot or more.
You may be chasing hundredths when the tools used by the photogrammetrist cannot realize your precision.
I appreciate the reply,
But I am not stressing about hundredths, not renting equipment, and the targets' positions have been determined already based on the only possible position for them. Not only is it a less-than-ideal site for GNSS, it's sister'ed with a heavy construction project we're doing as well. So it's busy, and some "better" spots for targets end of being staging areas for heavy equipment for example.
The site and construction is on top of hill/mountain, with many multi-story buildings on a topographically diverse landscape, where some of the targets go. The others are on the narrow canyon roads below with power lines, houses and trees, and some on the neighboring ridges surrounding (which I will hike to).
Plain and simple, it's a challenging area for GNSS work. I already have tried to get signal in every location.
Some of them I got good results, the others have to be traversed in.
And that's where this post originated, as I was curious about common field practices related to that aspect.
good video. I learned about lat/long being the "true" measured positions, and grid coordinates are the calc'd ones. If you have lat/long and elevation, you can always re-establish things.
Also was interesting seeing the comparisons of the 3 different methods of establishing scale factors.
