The reason for running Bin extract is the fact that the files are extremely large and in ascii. Accessin sub-regions are a factor of 1000 faster (if not more) using binary files. Ascii files are compatable between platforms. Binary files are NOT. Therefore you need to have a fortran compiler Please also follow the steps below: 1) download the DTU10*gz files 2) run gunzip on the downloaded DTU10 files (or use the microsoft unzipper under windows) 3) download the gbin.f, gbin_Xmin.job and the BinExtract_Xmin.f files. 4) add these to the correct directories (BinExtract_1min to the 1 minute files etc - gbin is the same for both). 5) make gbin (using fortran compiler) 6) make BinExtract (using fortran compiler) 7) run gbin.job Please check that you have DTH10XXX_1min.bin files for all quantities in the directory. They should roughly have the size of 900 mb 8) run BinExchange Notice that you outputregion is in most cases shifted by half a minute due to the gridspacing is off by half a minute (1/120 degree). Any questions oa@space.dtu.dk Best wishes Ole