<html><body><div style="color:#000; background-color:#fff; font-family:garamond, new york, times, serif;font-size:8pt"><div>How easy would it be to use alternative data sources for height map lookup? In particular in the UK we have available some 50m post spacing open data from Ordnance Survey, which is much more consistent and reliable than CGIAR or SRTM data sources.<br><br>https://www.ordnancesurvey.co.uk/business-and-government/products/terrain-50.html<br><br>Also how can tunnels/bridges be handled better (for example when following a disused railway path through a tunnel, the current implementations default to taking the ground surface level for the underground route, rather than a direct interpolation between the two end points of the tunnel... and the same point, in reverse applies to elevated routes and bridges over other roads, rail, rivers etc... (Ideally there would be a rise over the bridge span, but even a direct interpolation would be an
improvement over dropping to the valley floor in each span.</div><div style="color: rgb(0, 0, 0); font-size: 10.6667px; font-family: garamond,new york,times,serif; background-color: transparent; font-style: normal;"><br></div></div></body></html>