MDI Image Quality, Plate-scale, Etc. plots

• Plate Scale

  • Full Disk Image radius in pixels, average of major and minor axis of slightly elliptical image.
    
  • Full Disk Image radius normalized for 1 AU SOHO-Sun distance. minor radius shown as "+" and major radius as "-" symbol. Vertical lines show times of commanded focus change.
    
  • MDI inferred plate scale error in average of major and minor axis fits. Ratio to plate scale reported in image headers. Vertical lines show times of commanded focus change.
    
  • Residual limb fit radius after removing effect of focus changes. The residual annual term and trend are believed to be due to power in the window due to a radial gradient in temperature
    

• Image Focus Position and Flatness

  • MDI Full Disk focus map. Units are "focus stops" of about 0.5mm each, or one depth of focus. There are 9 positions avaliable labeled 1-9. Optical path length increases with focus number.
    
  • mdi_focus_actual.gif
  • mdi_focus_change.gif
  • mdi_residual_focus.gif

• Window Temperature

  • mdi_front_window_temp.gif
  • window_fit_linear.gif
  • window_fit_quadratic.gif

• MDI Light Throughput

  • fd_ice_central_mean.gif
  • ice_fd.gif
  • ice_fit.gif
  • ice_hr.gif