It seems to me, that worse the environment, the more prone GPS is to making errors. And, it goes up exponentially, not linearly.
So, double checking in these environments, become increasingly hard, the worse the canopy.
BUT these are the very shots, that NEED checked.
That's my experience.
Nate
How often do you find a bad one?
With my old gear, it eventually became a game... look at the canopy... and say, yes, no, or 1 hr.
If it was yes, I'd do it. If it was 1 hr, it was usually pull out the total sta. Unless it was a long ways from a field... then, I occasionally spent 2 hrs,
With the new gear, well, I have NEVER caught it lying to me.... If I leave the double check mechanisms switched on.
(By more than 0.14') With the new gear, I don't think I have spent more than an hr. I have spend 45 min before.
That's a boat load of data. It can post process as well as RTK, so it works good.
Nate
Nate,
What is your workflow in tree canopy to search for wood hubs and to set the monument corners?
TIA,
Larry
Isn't there a point of diminishing returns in an attempt to use RTK in dense canopy when it might just be more time effective to RTK in some points in the open to use for a short TS traverse? I just seem to see more and more resistance to breaking out the TS in times that call for breaking out the TS.
Search? Stake?
They are a bit different...
The LS gives a fix almost anywhere. But, it's something akin to a "High Quality Float" in the old gear.
You use this fix to get close... usually within 1 or 2 ft.
Then, you press "Start" and it cooks out the shot. When, it's done, it is giving you:
Brg, or AZ, and dist to corner.
And, Left/Righ, dist
and Foreward/back dist to corner.
Using these, you can then use a box tape, and make a dimple, or set the monument.
THEN, I always move up on the corner, and repeat.
This is just my double check. I then store this shot.
In light (Light canopy, for the LS is heavy canopy for the old gear) canopy, I often don't let it go through more than a minute, before moving up to the corner... then I do a full 3 min observation, to store the final corner coordinate.
Just how I do it. Others have worked out other ways.
N
Williwaw, post: 427005, member: 7066 wrote: Isn't there a point of diminishing returns in an attempt to use RTK in dense canopy when it might just be more time effective to RTK in some points in the open to use for a short TS traverse? I just seem to see more and more resistance to breaking out the TS in times that call for breaking out the TS.
Yes there is a point where it would be faster to get out a TS. However, being solo I don't always look at how long the job will take I also look at how difficult it is going to be to get the shot with a total station and how much manual labor it is going to take. For the rural boundaries that I do, it is still faster to wait on the GPS (whether it is PPK or RTK).
Does the Javad LS RTK work in the woods? If so, do you need to set up a base or can you use another correction stream?
It is always better to use your own base, regardless of brand.
Yes it works well in the woods. You can also use other correction streams.
Williwaw, post: 427005, member: 7066 wrote: Isn't there a point of diminishing returns in an attempt to use RTK in dense canopy when it might just be more time effective to RTK in some points in the open to use for a short TS traverse? I just seem to see more and more resistance to breaking out the TS in times that call for breaking out the TS.
Williwaw, Canopy has many meanings. Under the old paradigm, dense canopy, that would be marginal at best, (maybe a 20-50 min observation) is a 3-4 minute observation. Shots that are literally unthinkable, are a 20-30 minute wait. OF course, this is my experience. And, I am saying this with the settings set for 100% verified.
You can work without verify, in the field, without some of the bells and whistles... but pressing "Start" is very useful. Even in a field.
Multipath has many sources... even in the field. The ground, being the main one.
I like it.
Nate
200' tall Redwood trees are a deal breaker for any GNSS system I have used. I have had some success in an opening or logged area with as long a static session as I could get to the point I have left them out there all night (behind locked forest road gates) but at least 4 hour sessions will cure a multitude of sins, if not all sins. Being on a ridge works better than down in a canyon.
I left an R4 running all night on the cowbell and it was still running the next morning when I got back to it but the typical batteries will run dead after about 6 hours when new. Night has the advantage of less ionospheric interference. It's a little nerve racking leaving my receivers out all night but it was winter and no one was out there. I don't think I would do it in summer.
John Evers, post: 427022, member: 467 wrote: It is always better to use your own base, regardless of brand.
Yes it works well in the woods. You can also use other correction streams.
Good to know, and I'm guessing results are better b/c of the faster (10Hz) sampling rate? But I prefer not to have to set up a base. More time and money.
David, I'd love to test em in the redwoods. I have walked through the tree, that you used to be able to drive through. Back, about 1977...
N
I suppose it depends largely on your mission. I typically am required to stake propery lines and easements based on the control I recover. I'm not going to sit around 15-20 minutes to make sure each of my stakes are correct. I'm going to set some strategically placed points with minimum multi path and grab the chainsaw and total station and get'r done old school. Best tool for the job. If I relied on GPS for those tough spots Id spend a lot of time sitting around staring at my feet.
15 minutes? You cannot set up a total sta, and chain saw your way in, and walk back and forth, 3-4x, and set your corner much faster, than I can.
I am relaxed, and go shoot some pics. And, read RPLSTODAY! Some are done in 3-4 mins. The time factor... I honestly believe is faster.
HA!
N
