RTK GPS

cohberg

Has anybody gone down the (expensive) road of implementing RTK GPS?

I'm thinking about pulling the trigger on a pair of ZED-F9P but spending $600+ USD for cm resolution seems excessive

Additionally with my home track of Sonoma Raceway I'm not sure my xbee backhaul will get all the way out to the other side of the track from the pits due to the terrain.

aol_of_RaceChrono

You'll also need a data channel with decent bandwidth between the two GPS. It's doable no doubt, but adds to the costs. A wi-fi router probably won't do, but a pair of LTE modems certainly will. Or one if you have reliable internets at the pits.

cohberg

Yes, as stated in the original post if I implement I would be trying to use a pair of XBee-PRO XSC (900 Mhz) radios to implement the link for RTK corrections.

I do get many data sims and have a couple ESPs with lte modems but space on the motorcycle is at a premium.

I'll likely test if the backhaul is "good enough" by streaming NMEA / RC2 sentences from the bike and seeing what kind of data loss I experience.

mmrizio

I have read a few times on RTK-GPS. I am also interested, but not an expert.
For me, the Real-time part of RTK is not a necessity. If I have the cm-level accuracy during analysis, it is sufficient. During the session, regular GPS accuracy works for me.

So it would be OK to only post-process the data with the corrections from the stationary station GPS data.
I am not sure whether that would be as simple as just keeping a log of the stationary/reference GPS during the session, calculating the "average location" and logging the x/y/z-axis drift over time. And post-process the race data using those deviations to recalculate all locations (plus speed, acceleration, etc.).
I guess it also depends on the accuracy of the moving GPS: It will not have perfect view of all satellites all the time, so will the GPS deviation be the same as in the perfectly placed reference GPS on top of your truck/tent/...?