[mkgmap-dev] HGT - getElevation()

Mon Jan 15 20:41:48 GMT 2018

Hi Gerd,

on your pictures it looks like shading form extended DEM doesn't match 
map features. Is it HGT with resolution 1200? Shading looks more 
detailed than on my map, which uses DEM created by BuidDemFile. I have 
to recompile my map to compare.

I have done different test. I have analyzed a round peak on a map and 
traced coordinates of the center of highest DEM value. All at zoom 20m. 
Than I looked up the coordinates on HGT tile in QGIS. There were good 
match, coordinates were max 5m from the center of a HGT pixel. Then I 
checked offset of DEM, it was about 7m north and 18m west.

For me it looks like shifting DEM works correctly, but I can't explain 
effects on your map.

-- 
Best regards,
Andrzej