SOFIE signal changes due to FOV drift using spacecraft pointing reduces SNR margins Band / Target Center Wavelength (m) V SNR Required / CBE Margin (random) Worst case induced V uncertainty (quasi-systematic in noise units) 12 arc-sec drift in any direction from lockdown at 2.5 arcmin* Margin after RSS of random + systematic 1 1 / O3 s 0.291 1.0e4 / 210.9 0.08 12.8 2 / O3 w 0.330 2 3 / PMC s 0.867 1.0e6 / 5.9 1.79 0.6 4 / PMC w 1.04 3 5 / H2O w 2.46 2.5e4 / 16.6 0.02 15.7 6 / H2O s 2.62 4 7 / CO2 s 2.79 3.0e5 / 1.4 0.19 1.3 8 / CO2 w 2.94 5 9 / PMC w 3.06 1.0e5 / 3.0 0.16 2.7 10 / PMC s 3.12 6 11 / CH4 s 3.38 4.0e5 / 1.3 0.23 12 / CH4 w 3.48 7 13 / CO2 s 4.32 4.0e5 / 1.5 0.17 1.5 14 / CO2 w 4.65 8 15 / NO w 5.01 3.0e5 / 0.9 0.26 0.9 16 / NO s 5.32 *Lockdown was moved within a radius of 2.5 arcmin and the signal change for 12 arcsec drift (over 10 / seconds / 25 km) was calculated. Numbers shown are the worst case for all possible lockdowns. Note: the drift induced dV signal uncertainty is the error in the corrected signal considering a regression to the signal change vs FOV drift, the measurement noise (from calibration), and the pointing error (from calibration). This analysis captures all of the errors and is our CBE.

Predicted SOFIE performance meets or exceeds Level 1 science requirements Geophysical Parameter Precision Required / SMA Margin / Rigid Mirror Margin Altitude Range, km Required / Current Vertical Resolution, km NIR cloud extinction* 5x10-6 km-1 / 5.9 / 0.6 78 – 85 / 75 – 90  3 / 1.5 IR cloud extinction 5x10-5 km-1 / 3.0 / 2.7 temperature 5 K / 1.5 / 1.4 70 – 90 / 15 - 95 O3 mixing ratio 0.1 ppmv / 50 / 12.8 78 – 90 / 15 - 105 H2O mixing ratio 0.6 ppmv / 17 / 14.0 78 – 90 / 15 - 100 CO2 mixing ratio 10 ppmv / 1.5 / 1.4 80 – 100 / 15 - 100 CH4 mixing ratio 0.05 ppmv / 1.3 / 1.3 30 – 90 / 15 - 90 NO mixing ratio 107 cm-3 / 0.9 / 0.9 80 – 95 / 80 - 110  5 / 3 Horizontal and temporal resolution requirements are met *This measurement is not an AIM Level 1 science requirement

SOFIE H2O retrieval simulation SOFIE H2O Measurement performance Required Current Best Estimate (Margin) Signal to Noise 2.5  104 4  105 (16) Retrieval Precision (83 km) 0.6 ppmv 0.043 ppmv (14) Retrieval Altitude Range 79 – 90 km 15 – 100 km Retrievals in the presence of clouds