Hi Henning, yes, we have specialized tools for this work, they make a good job and we should use this tools. A little interesting idea is: If we can use additional use tif's a "container" for dem data, we can safe space on the hd. My little test with the copernicus files show: 5.2GB for zipped hgt's and only 3,54GB for the tif's with lzw compression (round about 68%). "container" means: only use 16-bit grayscale values, no metadata, no coordinate reference system or whatever. A "on-the-fly-conversion" is to expensive. You ask: Are the copernicus-files so much better compared to the viewfinder-hgt files? How we can decide this? I believe, there is no way. I have not found any information about the +- interval for SRTM or the viewfinder-data. I only know, that the copernicus-files have the 25m resolution from tanger up to the north cape in norway. Frank --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus