This task constructs the PPS product, grism spectra,
extracted from an Optical Monitor image obtained
with one of the OM grism-filters. The image
is previously undistorted by omgprep
and
rotated in order to align the spectra with the
image columns.
The task makes use of a source-list produced by running
omdetect
on the same image. The output
file contains tables with background subtracted spectrum
rates & corresponding errors, background rates & error,
spectrum flux & error. All rates are in 
Å,
and the fluxes are in 
/Å.
