iraf.net

NUMBER:	462
MODULE:	dispcor
SYSTEM:	V2.11.3
DATE:	Tue Feb  1 16:16:57 MST 2000
FROM:	valdes

BUG:	DISPCOR does not work correctly when linearizing spectra if there
	is more than one aperture in the file (that is multispec format
	data) and the aperture numbers are different than the line
	numbers.  This was found in the reduction of multifiber data where
	the aperture numbers are set to the fiber numbers.  What happens is
	that the dispersion solution from the wrong spectrum is applied
	during the linearizing.  There is no indication that the dispersion
	correction is incorrect.  The workarounds are to make sure that
	the aperture numbers correspond to the line numbers, to
	separate the spectra into individual 1D format, or to use
	'linearize=no'.

STATUS:	This is a serious bug, particularly since there is no obvious
	indication of producing the wrong result.  A patch to V2.11.3
	is required to fix this problem.