[OSM-talk] OTG rule, borders & mountains existing | Re: Crimea situation - on the ground

[Martin Koppenhoefer]

Am Do., 13. Feb. 2020 um 08:41 Uhr schrieb Colin Smale <
colin.smale at xs4all.nl>:

> Locations are stored in OSM as pairs of {lat,lon} and I assume these are
> both 64-bit floats in the database.
>
>
> AFAIK they are stored as integers (shifting the decimals)
>
> If so then then my comments about preserving precision still apply to all
> "client" software and I bet the majority uses float. Then an innocent
> update to a tag on a node can end up unintentionally moving the location
> slightly, losing precision.
>
>



My comment about precision lost through conversion was not about missing
floating point digits, but about conversions from one CRS to another, where
you may need additional (proprietary) grid parameters to do a high
precision conversion.

Cheers
Martin
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