In the scheme described in the previous Section, the correction for the blaze
function and for the chromatic response is done using standard stars. When the
input data sets do not include standard stars it is possible to correct for the
blaze function using a model of this effect as described in
Chapter 
.
This alternative reduction scheme is called IUE method because of its resemblance to the IUE spectra reduction. The first steps of the reduction are identical to the standard method, i.e. one should start with CALIBRATE/ECHELLE and after that run FLAT/ECHELLE optionally. The command RESPONSE/ECHELLE should of course be skipped. The IUE-mode is set via
SET/ECHELLE RESPMTD=IUE
To reduce the data enter the command
REDUCE/ECHELLE input output
where input is the raw image,
command
MERGE/ECHELLE output name order1,order2 NOAPPEND
where name is the root of the name for output files with up to 4 characters, order1,order2 defines the order range and NOAPPEND is a required command option.