[OSM-talk] What does WGS84 mean for openstreetmap these days?

[Greg Troxel]

"Jóhannes Birgir Jensson" <joi at betra.is> writes:

> I don't think we can or will be providing accuracy up to cm when most
> of the stuff we map from our chairs is off by a meter or two anyways -
> the beauty is that it doesn't matter for 99,99% of users. If a
> centimeter matters then we are probably dealing with legal matters and
> there OSM makes it quite clear it is not suitable for such.

My actual proposal, as opposed to the things I pointed out I wasn't
proposing, is about removing the ~2m uncertainty that exists from our
current definition.

As for cm level, OSM does not have accuracy specifications and won't.
Some people like to be accurate, and others like to add lots of detailed
tags.  Between us we have great map.  I don't agree that anybody who is
trying to be more accurate is necessarily concerned with something that
is "legal".  I would expect many people would like to see better than 2m
accuracy.

Certainly cm-level is very difficult, and I see that as being pretty far
out in the future.

You didn't comment on the notion of defuzzing the reference to WGS84, so
I'll assume you are ok with that.

> Also regarding the accuracy, as another fast moving country Iceland is
> actually splitting in the middle and so it edges west and east and
> south as well, depending on where you are in the country. We've had 3
> official national datums now, ISN93, ISN2004 and ISN2016 (helpfully
> naming them after years). The fact is that pretty much everything is
> still running in ISN93, ISN2004 saw very little uptake and ISN2016 has
> started very slowly.
>
> So for Iceland we do know that we are never going to achieve a
> centimeter accuracy, pretty much ever, and don't expect a free people
> sourced geographical database to reach it.

Interesting about the datum history.  But this is the cm strawman I
wasn't talking about, not the 2m issue.

I would not be surprised if in 20 years OSM had some approach to
coordinates of crust-fixed points.