1) The document discusses determining the amount of water vapor along flight paths of the Stratospheric Observatory for Infrared Astronomy (SOFIA) aircraft to improve infrared astronomy observations. 2) A global atmospheric model from NASA Goddard Space Flight Center is used to calculate water vapor loading along planned flight paths and compare to actual sounding data. 3) Accurately predicting water vapor levels will help SOFIA plan flights to regions of lower water vapor absorption to obtain better quality imagery.