On Fri, Jan 8, 2016 at 9:47 AM, Colin Smale <colin.sm...@xs4all.nl> wrote:
> > > How did all the elevation data get into OSM in the first place? > The elevations of peaks in the US came from the GNIS import. In turn the GNIS elevations came from the National Elevation Dataset (NED) [1], and it mostly uses the North American Vertical Datum of 1988 [2]. The other problem is that these are not "spot elevations" and therefore the elevation of a peak in the GNIS does not - in most cases - match the official elevation (the ones shown on the old USGS Topo maps and published by the National Geodetic Survey[3]). [1] http://nationalmap.gov/elevation.html [2] http://www.usgs.gov/faq/categories/9865/4921 [3] http://www.ngs.noaa.gov/datasheets/ >
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