[FOSS-GPS] Rtklib Why do I require a base station

[David Kelley]

David and Michael:

Sorry, coming to this thread a bit late....
I see that there are some basic posts on how this work that are 
generally correct, but the 2nd process to

> Or maybe I can do this. I can find the base station location(I dont know
> how). Then I can put the base station receiver there which is static. This
> way I would know the amount of error because I will subtract ERROR= (actual
> base station value) - (myreceiver base station value). Then with my final
> readings with moving rover receiver I can subtract the error and it will
> give me the readings with lesser error.

Is the way to do it.

You problem is then to collect (at least 4 hours, but 24 is better) of 
stationary data from the base station in the position it will remain. 
You can then put it into RTK with one of the tabs.  [There is also a tab 
in the post program to just use the first set of observations from the 
base and solve that and call it perfect, good for a 1st cut and testing]

If the base station is L1/L2 (or L5) capable, send you data to OPUS, if 
it is only L1 capable then send it to the Canadian PPP service.  Use the 
data you get back.

www.ngs.noaa.gov/OPUS/

http://webapp.geod.nrcan.gc.ca/geod/index.php?userlang=en
http://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php

As I type this (08/01/2014 at 15:40:10 UTC)  the OPUS site appears to be 
down.   The NRCAN site requires a sign up, which is easy. Both of these 
should be part of your basic set of tools.

A very interesting experiment for people learning about all this to do 
is the run two copies of RTK nave on the two GNSS devices, both in 
autonomous mode ("single in RTKLIB terms) and watch the two plots 
evolving.  You will easily see that both devices are influences the same 
effects and tend to wonder together.   This is great graphical way to 
show people the "differentiable" aspects of the process.

Regards,
David Kelley