A trajectory or concentration simulation only requires one file called CONTROL, which defines various model parameters and other input and output files. An optional file called SETUP.
CFG may be present to define more advanced simulation features. The Graphical User Interface (GUI) provides a user-friendly way to create these files, set any other command line options that some of the post-processing graphics programs may require, and run HYSPLIT and associated programs. Alternatively, the CONTROLand SETUP.CFGfiles can be created with any text editor, such as Notepad, and then HYSPLIT and its associated programs can be run from the DOS command line.