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

[Scott Ellis]

David, have been watching the list for a while and you may know the 
answer to this.

If all I am after is relative positioning information i.e. relative to 
my base station, how accurate does the base station position entered 
into RTKLIB have to be, and what effect does this have on the relative 
accuracy - if any?

Scott

On 2/08/2014 1:59 AM, David Kelley wrote:
>
> 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
>
> _______________________________________________
> This message is sent to you from FOSS-GPS at lists.osgeo.org mailing list.
> Visit http://lists.osgeo.org/mailman/listinfo/foss-gps to manage your 
> subscription
> For more information, check http://wiki.osgeo.org/wiki/FOSS-GPS
>