Boundary Vector Length

[Steve Douty]

We all know that within reason, short base lines (vectors) are good between the base and the rover. After all it’s in the JAVAD adds! However, we also know that finding a base location that has great sky and that we feel is secure enough to leave our base and support equipment in is also a wonderful thing to find.


So, the question becomes; if we find a perfect place for our base (sky and security), what are the limits of vector length and time of processing between base and rover that are practical? I think that somewhere between 6 and 12 miles we start losing precision and accuracy that will support boundary surveying. What do the experts say? Any proof or practical examples?

 

[Nate The Surveyor]

Well, first off, I don't know the definitive answer to your question.
HOWEVER...
I have done the following:
Set the base on a 25' tall HIXON rod, with bipod, all tied down. I believe the Height of Target was at 16'. (Long rods, without using the smallest section of rod, are very stiff)
This let me use a LOCAL base site. This was with my old LEGACY E system. Even if the bubble is not perfect, set it up 100% identically, each day. It will be within a hundredth or two, each time.
Now....
Using a Javad, you might be able to set the base up on a site 10+ miles away, and work for a day. (Just to get a dpos)
NEXT DAY, set the base up on a tall rod, as I did above, and CLOSE to the site. So long as it is STABLE, you should be able to set it up with autonomous solution, and "Reverse Shift" it in. Or, M-Local.
This would effectually get you an "On site" base. IF there was a place where a tall rod would allow good sky view.
Just thinking out loud.
OR, you might set the base every day on the SAME 16' rod, and set control, that is in the clear, for a reverse shift, or dpos.
I absolutely like the versatility of the M-local etc.
Nate

 

[Javad]

Rule of thumb is 1ppm. one millimeter of error for every kilometer of base-rover length.