As it has been pointed out, OM grism data are image mode data. Since tracking corrections are not applied to grism data, spacecraft and summary files are needed:
0472_0125910501_OMS00500WDX.FIT - Exposure priority window file 0472_0125910501_OMS00500IMI.FIT - Exposure image file with grism data
and the process will be run in the following way
step1> omprep set=0472_0125910501_OMS00500IMI.FIT \
pehset=0472_0125910501_OMX00000PEH.FIT \
nphset=0472_0125910501_OMX00000NPH.FIT \
wdxset=0472_0125910501_OMS00500WDX.FIT \
outset=g0125910501OMS005IMAGEI0000.FIT \
modeset=4
The input image corresponds to a user defined window. In the case of full frame low resolution exposures, the task omcomb must be run beforehand and its output image be used as input for omprep
step2> ommodmap set=g0125910501OMS005IMAGEI0000.FIT \
mod8product=yes \
mod8set=g0125910501OMS005MOD8MP0000.FIT \
outset=g0125910501OMS005IMAGE_0000.FIT \
outflatset=g0125910501OMS005FLAFLD0000.FIT \
nsig=3 nbox=16 mod8correction=1
step3> omgprep set=g0125910501OMS005IMAGE_0000.FIT \
outset=p0125910501OMS005RIMAGE0000.FIT \
undistset=u0125910501OMS005IMAGE_0000.FIT
This undistorted and rotated image is the one from which the spectrum, or spectra, will be extracted.
step4> omdetect set=p0125910501OMS005RIMAGE0000.FIT \
regionfile=g0125910501OMS005REGION0001.ASC \
outset=p0125910501OMS005SWSRLI0001.FIT \
nsigma=2
The source spectra have been detected. They can be checked by overplotting the region file on the rotated image, using ds9.
step5> omatt set=p0125910501OMS005RIMAGE0000.FIT \
sourcelistset=p0125910501OMS005SWSRLI0001.FIT \
ppsoswset=g0125910501OMS005SIMAGE0000.FIT \
usecat=no rotateimage=yes tolerance=3 maxradecerr=1 maxrmsres=1.5
All detected spectra have been assigned RA and Dec. A sky, north aligned image is also produced.
Spectral extraction will be done now
step6> omgrism set=p0125910501OMS005RIMAGE0000.FIT \
sourcelistset=p0125910501OMS005SWSRLI0001.FIT \
outset=p0125910501OMS005SPECTR0000.FIT \
bkgoffsetleft=6 bkgwidthleft=-6 bkgoffsetright=6 \
bkgwidthright=-6 spectrumhalfwidth=-6 spectrumsmoothlength=0 \
extractionmode=0 extractfieldspectra=no \
outspectralistset=p0125910501OMS005SPECLI0000.FIT \
regionfile=p0125910501OMS005REGION0001.ASC \
spectraregionfile=p0125910501OMS005SPCREG0001.ASC \
addedregionfile=0
Target spectrum, or all spectra in the field of view if
extractfieldspectra=yes
is used, are extracted and calibrated.
Finally, the results can be plotted.
step7> omgrismplot set=p0125910501OMS005SPECTR0000.FIT \
binsize=1 plotdevice=/PS \
plotfile=g0125910501OMS005SPECTR0000.PS \
scalebkgplot=no plotflux=2 \
spectraregionfile=p0125910501OMS005SPCREG0001.ASC \
regionplotfile=p0125910501OMS005SPCREG0001.PS \
rotatedimageset=p0125910501OMS005RIMAGE0000.FIT
A PDF version of the plot is also produced.