Direct IP RTK surveying

Hi there,

I'm conducting a thesis through my university in Queensland,
Australia, regarding the use of internet protocols and GPS RTK
surveying.

I'm looking at setting up a base station connected to a computer and
dialing into the computer from the rover,
using the computers i.p. address and port number. This is Direct IP.
I will be testing things such as accuracy, repeatability, latency etc.

I'll be using the magellan promark 3 reciever for my base and rover.

With this I hope to extend the distance that i can survey. Currently
the Promark3 has a limit of about 1.5 -3km with 2 watt radios. With
direct IP it may be possible to go even further.

I'm wondering if anyone has perhaps tested or utilised direct IP
before?
I will be looking into NTRIP but primarily focussing on direct IP.

If you have any research papers, articles or links or anything to
share can you please contact me at survey@hotmail.com

Regards,

Scott Taylor
Global Surveyors
www.globalsurveyors.com.au

On Tue, 1 Apr 2008 20:41:34 -0700 (PDT), Global Surveyor


Scott,

What distance does Magellan specify as the maximum that the rover can
be from the base and still do effective RTK positioning? The sensible
mathematical limit for RTK from Trimble is usually stated as about
20kms, and I believe there was some Magellan/Thales talk about
extending that out to 40-50 kms by some new calculation tricks they
had invented. This has nothing to do with radio range. Near or past
this distance, it takes far to long to do the math to get a "fixed"
solution from a "float" solution, which is probably why no one has
bothered much with a solution to the radio range problem in the past.

- Tom

Hi there. Thanks for the reply.
I've been told that with 0.5 watt radios the range for RTK is about
1.5km line of sight and 300m - 700m in built up urban areas.
If you increase the radio to a 3rd party 2 watt radio the range can be
increased to 1.5 -3km in built up urban areas.
In Magellan's documentation they say <10km. ( most GPS suppliers state
the same - for good practice! )
It will be interesting to see how far I can go and get a fixed
solution and to test the accuracy on other known marks.
Stay tuned on my website www.globalsurveyors.com.au or the mailing
list and I'll let you know how I go.
Thanks for your comment.
Scott
I