Post base station coordinate setup – Pixhawk RTK

Q&A forumCategory: QuestionsPost base station coordinate setup – Pixhawk RTK
Thiago Kern asked 2 weeks ago
Supposing I have to survey some land with a Pixhawk RTK uav (ardupilot) and have to perform a PPP for my base station point, after the flight because here in Brazil our  governamental gnss positioning network requires at least 48h to get a precise position. How can I insert the new base station coordinates to get the adjusted geotag locations of the images of the survey?
The only method that I’ve came so far is to open de geotag file on Autocad or Qgis and manually offset all points considering the new base station position.

1 Answers
clive1 answered 2 weeks ago
I’d probably apply the offset/bias mechanically to the file
Perhaps long term the best strategic approach would be to establish your OWN reference points and network, throughout your work area.
If you record your own raw CORS data at your office you can use that immediately upon your return rather than wait 24 to 48 hours for the government CORS to spill their data to the central server. You could also broadcast your RTCM3 data to yourself real-time, and use that to establish the base stations you set up in a relatively rapid fashion.
Not sure of the topology of the area in question, or the vicinity of adjacent properties, farms, etc where you could establish infrastructure or hard-mount an antenna pole or survey point you could revisit later, or serve/broadcast data from.
Thiago Kern
replied 2 weeks ago

Thanks for your reply Clive!
Usually we survey big farms and roads, so we’re talking about long base line. That’s why i’m trying to find a solution for it. I’m very used to the PPK method, that solves this issue, but requires some office hours to post-process everything.
What do you mean by “apply the offset/bias mechanically to the file”?

replied 2 weeks ago

I’m not familiar with the specific tools / procedures you’re using, but I would tend to back-fit number directly into files containing UBX or NMEA data as part of some inter-stage process, automatically, rather than manually. Anything dull and repetitive is an immediate candidate for a coded solution.
Before the ZED-F9P I was using NEO-M8P and M8N devices in small boxes recording hourly RINEX data in a continuous logger, basically a low-cost spider system. L1 raw measurements from uBlox device were capable of yielding sub-cm convergence in Post-Processing. Anyway it allowed for low investment and high availability of data.

replied 2 weeks ago

CORSLITE – RINEX Data Logger using STM32F746G-DISCO and ArduSimple RTK shield with uBlox ZED-F9P