## Importing Herschel-HIFI FITS

Once you have installed a correct version of CLASS, importing Herschel-HIFI FITS is as simple as opening a CLASS output file and calling the command FITS, e.g.

    LAS> file out myfile.hifi single
    LAS> fits read herschel-hifi.fits

Depending on the observing mode and on the pipeline level used in the Herschel Common Science System (HCSS), CLASS will produce one or more spectra from a single FITS file. Once this is done, you can retrieve the spectra as usual in CLASS, e.g.:

    LAS> file in myfile.hifi
    LAS> find
    LAS> list
    LAS> get first

The first spectrum is stored in the R buffer and is ready for reduction with the CLASS analysis tools.