A list of the inputs needed for the psf tools


** PSF_model **

 1) HRMA PSF images at surface of best focus (images)
             images for shell pairs (1,3 & 4,6) and 1,3,4,6

 2) PSF blurring function for defocus
           or
    HRMA PSF images for max defocus for tilted chips (images) for
			 ACIS-I 
			 ACIS-S
			 HRC-I
			 HRC-S
 3a)Intrumental PSF's (2-D functional forms) for
      HRC (in hand Gaussian w/ sigma=18um)
      ACIS-I/S for standard grade
      ACIS-I/S for each? grade

 3b)Intrumental PSF's (1-D azimuthally averaged functional forms) for
      HRC (in hand Gaussian w/ sigma=18um)
      ACIS-I/S for standard grade
      ACIS-I/S for each? grade

 4) Grating LSF's (functional forms) for
      HEG
      MEG
      LEG
    for the 1-D and 2-D case




** PSF_calc_fraction **

 Table of Enclosed Energy Fraction vs Energy and off_axis angle
   and
 Input from PSF model

** PSF_calc_size **
 
 Table of characteristic size (say 50% and 90% enclosed energy) compiled
 on an energy and offaxis angle grid.
  and
 Input from PSF model for arbitrary EE fraction