Calibration and Science Requirements for the LETGS

• In-flight calibration strategy (again...zzzzZZZZ)

• Science requirements and drivers for calibration goals and current status

  • Effective area; Dispersion relation and LRF

• Effective area

  • Recent progress; Low E QE monitoring

• Future work

  • Cross-calibration with XMM
  • Imaging non-linearities
  • Higher order efficiencies

Notes: