i want to make a 3d modell out of the mount everest and some other mountains. what i need therefore is a 14km² square around the peak from the mountain. so basically i use qgis to extract the area from the dowlnoaded SRTM geoTIFF (which i downloaded here http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp). qgis only needs the left upper and the right bottom corner of the areal, which i calculate with this site http://www.gpsvisualizer.com/calculators. So far, so good... now qgis cuts a rectangle!! but if i use microDEM to convert to a greyscale BMP i get a square shaped picture again!?!
the dem information of the bmp are the following:
Size: 13.92x13.95 km-------------> square (but not 14km²)
DEM size: 171x152----------------> no square
Screen Pixels: 517 x 518----------> almost square
Screen pixel size: 26.94 m
z range: 5040 to 8806 m
does anyone know what the heck is going on? i am really baffled and really dont know how to deal with this situation...