On Monday, 4 July 2005 15:04, Jon Stockill wrote: > I converted a chunk of SRTM data to 10m interval contours, and overlaid > this on an ordnance survey map (using mapserver) - the results are > actually incredibly close - the 0 point of the two datasets is obviously > slightly different, but the two datasets fit together remarkably well - > Obviously I have no idea how good the data is for the rest of the world, > but the UK data seems surprisingly accurate, which leads me to my > question - is there really such a huge problem with our source data, or > do we just need to be generating scenery with more polygons?
SRTM3 is very coarse. What I had problems with were airports that are on hill tops or steep terrrain. One example being KAVX. One would need a DEM with a <= 5m sample spacing and about 1 meter vertical accuracy around such airports. SRTM's vertical accuracy is only guaranteed to be within 16 meters! It's usually within 10 meters but that is still a large error when dealing on a micro scale. Also what about custom mods like Alcatraz? There is going to be a need to custom tweak scenery with regards to both the DEM and the vector overlays (roads, rivers, railroads, powerlines, etc). Having everything in one DB with a single TG exporter interface is going to make life a lot easier in the long run in my opinion and there are numerous advantages which haven't been discussed yet. Regards Paul _______________________________________________ Flightgear-devel mailing list [email protected] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
