...
By default, you are started in the "setup" tab, which requires only two simple operations. First, you can choose the directory where firehose looks for the raw data, if you did not use the default value suggested above. Firehose will never overwrite files in this space, so your raw data will remain safe.
Likewise you can change the location of your reductions directory if not in the standard location, using the second box. This option has not been extensively tested in the software.
Next you can enter your Magellan-formatted observing catalog into the second third box. This is used by the software to match exposures of the same object when organizing for the reduction process. It is more efficient than using header information since it groups objects by where the telescope was pointing and matching that to your object list, thereby avoiding operator errors at the telescope. It also checks against the FIRE list of known telluric standards to determine which exposures are science targets versus calibrators. If you choose not to enter the catalog, firehose will attempt to organize based on header information. All settings can be over-ridden manually later in the process.