Sources of Error

• Thermal gradients in the air column will cause ‘seeing’ errors

  • Take several interferograms and average the Zernikes

• Imperfections in the interferometer optics

  • Use tested, certified optics for the critical components

• Interferometer alignment errors

  • Remove Coma from the analysis

• Gravity-induced astigmatism

  • Rotate the optics, take several interferograms, de-rotate and average

Notes: