Back-propagating the light of field stars to probe telescope mirrors   aberrations
  We propose a wavefront-based method to estimate the PSF over the whole field of view. This method estimate the aberrations of all the mirrors of the telescope using only field stars. In this proof of concept paper, we described the method and present some qualitative results. 
Ferr\'eol Soulez, Fr\'ed\'eric Courbin and Michael Unser
astro-ph.IM