Eric S's Diary Comments
Diary Comments added by Eric S
Post | When | Comment |
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You thought OpenStreetMap data uses the WGS84 datum? No it doesn't! | In France, in Grenoble’s suburb, I used my Garmin Etrex 30 (GPS+Glonass) with my bicycle to record tracks. I drove precisely at the junction between light and dark areas: https://www.mapillary.com/map/im/xFBBFuiCsI6Pu-WK4dsGbw Now, you can see the report in JOSM: Background are orthophoto and cadastre both in RGF93 (i.e. local datum that was mostly aligned with WGS84 in 1993). So, even with a consumer product, we can touch the problem. |