Relative Mode Functionality for Moving Base RTK Setup

GPS/GNSS
1

I am using the sparkfun quadband lg290p module.
My intended setup involves a moving base station installed on a vessel, with multiple rover units positioned on the deck. The goal is to obtain precise relative positions of the rovers with respect to the base station, enabling accurate localization of each unit onboard the vessel. The vessel’s orientation is known through other sensors.

I configured the system to operate in relative mode, but I am unable to obtain relative position outputs from the rovers. They continue to output only standard NMEA GGA messages, which provide absolute geodetic positions.

Could you please clarify the following:

  • Is relative mode intended to support this kind of moving-base setup?
  • If so, is there a way to obtain the relative position (e.g., X/Y/Z offsets) of each rover with respect to the base station?
  • If not, what is the purpose of relative mode in the firmware?
  • Are there recommended steps or additional tools required to implement such functionality using those devices?
2

You ask great questions but I haven’t used the LG290P in a moving base setup. I recommend asking on the Quectel forum, and then, if you have the time, please let us know what you learned so we can educate others.