.. NPOL Reference File TSR master filee.

TSR 2012-03: NPOL Reference File
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NPOL Reference File TSR
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.. abstract::
   :author: Nadezhda Dencheva, Warren Hack
   :date: 12 Oct 2010
   
   The HST pipeline originally used two types of reference files to correct for distortion: 
   ``IDCTAB`` files which contain the coefficients for a polynomial correction and 
   ``DGEO`` files which are images with the residual distortion. A new format for the residual 
   distortion, called ``NPOL`` files (extension ``_npl.fits``),  is presented in this document. 
   The conversion from ``DGEO`` files to ``NPOL`` files is described and an example of the format is given 
   using ACS/WFC F606W filter. Tests of the conversion procedure show that the 
   differences between the ``DGEO`` files and ``NPOL`` files are of the order of :math:`10^{-4}` 
   pixels.
   
Contents: 

.. toctree::
   :maxdepth: 2
   
   npol_tsr 
   
Indices and tables
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* :ref:`search`

