RTK "Year to year"

Q&A forumRTK "Year to year"
DAvids asked 3 weeks ago

Hi all.  I´m seeding withRTK with a precission below 2 cm.
I thought by using RTK i could get back a couple of days or months later and drive through the exact recorded set of points but i get about 30 cms error after 2 days.
Is that normal? 
 
Regards
 

Ardusimple Staff replied 3 weeks ago

Hi DAvids,
If you are using an LR/MR kit, they provide very good relative accuracy or pass-to-pass accuracy, but the absolute accuracy by default is in the range of 2-3 meters. If you want to have also absolute accuracy of 2-3cm you need to calibrate the base station position.

Above means that if you switch OFF the system and turn ON again, the base station will have a different calibration and you will have an offset respect the previous day. In order to avoid this, you need to “store” the base station position of the first day into the base station non-volatile memory, this can be done with the message ubx-cfg-tmode3, fixed option.

1 Answers
DAvids answered 3 weeks ago

Thanks! Didn´t know you had sto store base station coordinates. I´ll give it a try.

I´m not usinf lora or similar but NTRIP client, but the procedure is much the same, roght?

REgards.

Ardusimple Staff replied 3 weeks ago

If you use NTRIP with your own base station, the same explanation as above applies.
If you use NTRIP with a 3rd party base station, then you should be able to replicate pass-to-pass accuracy between consecutive days (absolute accuracy). If this is not the case, check that you are actually connecting to the same base station and/or that the base station is correctly calibrated.

DAvids replied 3 weeks ago

Umm This is worse. I´m using NTRIP with a 3rd party base station, always the same, and to the same service (mount point( It´s a gobernamental station so i gues it has to be perfectly calibrated.
That´ll be harder to troubleshoot I´m afraid.
Thanks!