Update datum on runtime.

[nPellejero]

Hello, we started to experience some issues when we are far from datum point (physically, many Km away.)
There would be any problem, or further unwanted consequences if we develop some mechanism to update datum on runtime? Maybe a service that we could call whenever distance between current position and Datum riches some threshold? Or check for Datum changes during the main while()

[bsb808]

Thank you for the issue. Can you explain what issues you have when operating far from the datum? I'd be interested in documenting this limitation.

If a service to change the datum at runtime would held your use case, I don't think that would adversely affect other uses. I can imagine that changing the datum could be a little tricky since it might introduce discontinuities in the positioning outputs. I'd encourage you to put in a PR to implement the functionality.

[nPellejero]

Hi, as a workaround, we made an external service that sets the datum with the current GPS position and restart geonav node. We are testing it and it seems to work just fine.

[nPellejero]

The issue we have was that some tf transformations were very choppy when seen in RViz, so the representation of our vehicle was really messy.