We have around 1800 1 arc-second SRTM tiles (Geotiff). How to effectively merge all the tiles into one single file ? We are thinking about splitting 100 files per folder and merge them together using QGIS merge. We don't have to create VRT as the client insists on a single tile.
My question is what are the parameters we have to tweak in QGIS Merge option ? There are few parameters in "Merge raster layers (through Processing tool)-Preferred data storage, Interpolation, Overlapping cells. Read somewhere, in case of SRTM tiles the first pixel line will overlap with the adjacent one. So do we have to use "First value in order of grid list" in case of overlapping cells.
Any kind of suggestions are welcomed.
Finally i've managed to merge 2600 files. Divided the files into five folders and created VRT for each folder of 515 files. Then converted VRT to Geotiff using gdal_translate command in OSGEO shell (with DEFLATE, PREDICTOR = 2 parameters). Original file size was around 6.25GB. But the compressed output was 3.25GB each.
Then i again created VRT for those five files and did the same translation.