Hi all,
Yes I messed up bad. I have a forested plot that is around 2 ha and have been using Reach RS2 Base and Rover units to capture point locations of every tree within this plot. A few days ago, in survey mode, I captured the locations of over 245 trees and felt really productive at the end of the day, only to find out I did not turn on my logging on my Rover.
Does anyone have any experience with this? Is there a workaround to post process points only captured in survey mode? Thanks for all of your help.
If you know the base coordinate you used during the survey, and assuming you had logging turned on for the base, you could PPK the base coordinate and calculate an offset from base station coordinate used during survey and to the PPK position.
You could then apply that offset to all of your surveyed points.
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I have the Base coordinate, but logging was not turned on either unfortunately.
Shoot… Did you record any previously known points during survey?
I did not, but I have 100s of previously known points from earlier surveys. I did not use the same base for those though. The site is close enough where I could set up the base again and collect some more control points, while logging of course
You could do that. Setup base and resurvey a few points really well. Then correct base to nearby CORS site and offset remainder points from before.
Thanks RTK_Hunter, that’s what I’ll do. Now I have to figure out how to use that offset for the PPK on the rest of my points. I’m kinda new to the RTK PPK world, used damn Trimbles for work before this.
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I don’t wanna jump in here (but I will.) Remember QGIS is your friend for shifting your “unknown” survey to align with your known one.
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@Brent_W I’m not sure I follow you. I actually have only used ArcGIS also. But I don’t have two surveys of the same points, I only have pre-existing points from different areas within the plot. The points I have recently acquired (without logging) are in a completely new area of the plot.
@RTK_Hunter was doing a great job of explaining and maybe I missed something. I’m sorry to add confusion.
Is there even one point you can re-identify and can go to and re-survey? Like one place you can see the indent of your pole or mark on a stump or pin or anything?
I have rebar in the ground where my base is always placed, and I have tags on over 1k trees with unique id’s. So I could go back to any one of the trees I recently surveyed and place the rover against it again (same tree id).
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Did you survey with a fixed solution or a single solution? You said you captured them in survey mode. Does that mean just a “single” solution?
I was able to get Float for each tree, a couple were fixed. Unfortunately the forest canopy in places prevents a fixed solution, perhaps if I stayed in place at each tree for a longer period of time, but that would take some time to get the work done.
I don’t know of any way for you to accurately recover your information. Obviously you can (1.go back and post process again to get the accurate position of your base station. Then 2.) measure one of the points that had a fixed position. 3. ) Match up that point by tree id with the same point from your first survey and shift all the old ones over. 4.)This will give you real world positioning but your relative accuracy will not have improved from the first survey. Probably some that are in a float solution are pretty close…
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I learned this lesson early on. Open up the logging page check your logs are enabled. Refresh, then check the logging page again. See that the numbers (filesize) on each log file have changed. Then feel confident to go about your work.
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Starting to bring up this issue again. I had previously ppk’d my base station and have a fixed position on my base, marked by rebar and I return to the plot and place it in the same position. So I have a fixed coordinate for the base, could I somehow calculate an offset to the unlogged rover point locations?
Hi Manuel,
Sorry for the delayed response!
I’d agree with our users: now you can calculate the offset for your base coordinate and apply the same offset to the points you collected in a fixed solution.
You can do the same with the points collected with a float solution status but the result won’t be centimeter-accurate.
Ok, I have the CSV from the survey, and it gives me the lateral rms for each point. I only have about 8 trees that have a fixed position to my base (which wasn’t logging but I have already ppk’d the position). What would the process be for “calculating” an offset, and then actually applying that to the rest of my points? Can I easily apply that to their coordinates in the .csv to then place on my map?
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I may have misunderstood your situation, but if your base was not logging when you were saving points on your rover then there is no remedy to get points’ coordinates after the fact.
I would like to know about this as well. @polina.buriak could you point us in the right direction please? 