For the snaphu program, please also refer to their website and read the man page. Doris is a wrapper for a system call to the executable snaphu. Therefore, a program called snaphu should be executable and in your path. An input file for snaphu is created in the current directory. You can rerun snaphu with a changed inputfile from the prompt if required (but keep same output file name, format as it is in the result file for the interferogram.) We assume to unwrap the complex interferogram, mph format always for snaphu.