From 7003ee7c9b62fc80b4dd593081ceb04925682867 Mon Sep 17 00:00:00 2001 From: dencheva Date: Mon, 11 Oct 2010 19:39:31 +0000 Subject: More docs git-svn-id: http://svn.stsci.edu/svn/ssb/stsci_python/stsci_python/trunk/stwcs@10521 fe389314-cf27-0410-b35b-8c050e845b92 --- updatewcs/det2im.py | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'updatewcs/det2im.py') diff --git a/updatewcs/det2im.py b/updatewcs/det2im.py index 993ec52..6eb7fa7 100644 --- a/updatewcs/det2im.py +++ b/updatewcs/det2im.py @@ -5,6 +5,32 @@ from pytools import fileutil import utils class DET2IMCorr(object): + """ + Stores a small correction to the detector coordinates as a d2imarr + extension in the science file. + + Notes + ----- + For the case of ACS/WFC every 68th column is wider than the rest. + To compensate for this a small correction needs to be applied to the + detector coordinates. We call this a detector to image transformation. + The so obtained image coordinates are the input to all other distortion + corrections. The correction is originally stored in an external + reference file pointed to by 'D2IMFILE' keyword in the primary header. + This class attaches the correction array as an extension to the science + file with extname = `d2imarr`. + + Other keywords used in this correction are: + + `AXISCORR`: integer (1 or 2) - axis to which the detector to image + correction is applied + + `D2IMEXT`: string = name of reference file which was used to create + the lookup table extension + + `D2IMERR`: float, optional - maximum value of the correction + + """ def updateWCS(cls, fobj): """ Parameters -- cgit