Well, having been one of the early guys, of "GPS ABUSED PROPERLY", I do have this to say.
GPS in the woods, DEGRADES the position. You get your best data in the open field. You get your best data, with redundancy. Static GPS, in the field, is some of the best data ever. (Kent McMillan is a fan of this approach). Then, ANYTHING in the woods, gets shot in, from "in the clear" control. This is your highest form of data. It's the best.
From this "Gold Standard", we go "downhill".
We now have RTK gps, in the edges of the woods... and it still works. But, we recognize a little error coming in. So, we mitigate it, with REDUNDANCY and TIME. Ok, we are pretty good now.
Then, we take RTK GPS, deep into the woods. Now, we find more trouble. 2' to 7' errors are common. So, we mitigate this with REDUNDANCY, this brings us BACK to the 0.2' accuracy. Then, we add more time, and we are down to around 0.10' accuracy.
In the thick woods, one shot, with "normal" gps, this level of confidence takes between 30 minutes, and 3 hrs. If it takes longer, we give it up. When we give it up, we have 2 paths to go....
1.) Accept the un verified coordinate.
2.) Go back to the wide open, get good control, and use conventional equipment, and bring our control in from the wide open areas, to the thick woods.
Now, for some persons, option 1.) above is ACCEPTABLE. (I am seeing this with some start-up solo guys, with used gear, or a LACK of experience, and a desire to put the business side above the quality side)
For me, it is NOT acceptable.
Javad LS has subroutines, in the data collection process, to mitigate the 5' and 7' and 2' errors.
And, a mechanism to bring the data back to the 0.10' area, and even tighter, when desired.
So, I am a Javad Fan.
Nate