1 SOFIE Performance, CBE as of 22 November 2006
GATS
SOFIE signal changes due to FOV drift using spacecraft pointing reduces SNR margins
Chan.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
11 / O3 s 0.291
1.0e4 / 210.9 0.08 12.82 / O3 w 0.330
23 / PMC s 0.867
1.0e6 / 5.9 1.79 0.64 / PMC w 1.04
35 / H2O w 2.46
2.5e4 / 16.6 0.02 15.76 / H2O s 2.62
47 / CO2 s 2.79
3.0e5 / 1.4 0.19 1.38 / CO2 w 2.94
59 / PMC w 3.06
1.0e5 / 3.0 0.16 2.710 / PMC s 3.12
611 / CH4 s 3.38
4.0e5 / 1.3 0.23 1.312 / CH4 w 3.48
713 / CO2 s 4.32
4.0e5 / 1.5 0.17 1.514 / CO2 w 4.65
815 / NO w 5.01
3.0e5 / 0.9 0.26 0.916 / 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.
2 SOFIE Performance, CBE as of 22 November 2006
GATS
Geophysical Parameter Precision
Required / SMA Margin / Rigid Mirror Margin
Altitude Range, km
Required / Current
Vertical Resolution, km
Required / Current
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 78 – 85 / 75 – 90 3 / 1.5
temperature 5 K / 1.5 / 1.4 70 – 90 / 15 - 95 3 / 1.5
O3 mixing ratio 0.1 ppmv / 50 / 12.8 78 – 90 / 15 - 105 3 / 1.5
H2O mixing ratio 0.6 ppmv / 17 / 14.0 78 – 90 / 15 - 100 3 / 1.5
CO2 mixing ratio 10 ppmv / 1.5 / 1.4 80 – 100 / 15 - 100 3 / 1.5
CH4 mixing ratio 0.05 ppmv / 1.3 / 1.3 30 – 90 / 15 - 90 3 / 1.5
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
Predicted SOFIE performance meets or exceeds Level 1 science requirements
3 SOFIE Performance, CBE as of 22 November 2006
GATS
SOFIE H2O retrieval simulation
Retrievals in the presence of clouds
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