Simon Poole <si...@poole.ch> writes: > Thus is a slightly tricky subject and it is not going away. > > For another aspect of it see > https://www.openstreetmap.org/user/StephaneP/diary/390290
Thanks -- I had not seen that. I would say that to be pedantic, there is a minor error in the post, in that OSM coordinates are by definition WGS84. Agreed that when people add points with coordinates that are in other datums, then the points in the database have errors. I am in the process of figuring out how to deal with this, as accurate locations in my state basically come from using the state's reference network, which gets you NAD83(2011) epoch 2010.0. > Essentially in some cases we are using imagery that isn't actually using > WGS84 as if it was (fsvo of WGS84 as you correctly point out) and we > currently don't actually have a way to correct this . And yes while > continental shift is for most countries smaller than all the other ones > when adding geometry, for Australia this not necessarily true. That's true for how people with editors generate coordinates. It seems quite possible to adjust imagery to WGS(G1762) in editors, and arguably that should happen. I wonder though how often imagery is sufficiently accurate in some national datum that this matters. I suspect it's more and more often. In my message, was really trying to deal with the issue that by saying "WGS84" instead of "WGS84(current realization)", OSM has a built-in uncertainty of about 2m before we even start talking about where data came from. That seems easy to take off the table with zero workflow changes. At least then there will be a clear definition of what's intended. Actually changing the notions is much more difficult and I was trying to separate the easy step from the harder ones. _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk