An improved method for MERSI water vapor retrieval using GPS calibration

Water vapor, one of the green house gases, plays many important roles in global environmental change. For instance, it has an impact on global water and energy circulation, heat transmission and climate of the world [1-3]. Additionally, water vapor is an important parameter in atmosphere correction of remote sensing [2]. The distribution of atmospheric water vapor varies significantly in both space and time domains. Specifically, water vapor in tropical area is 10 times more than that near the poles and changes temporally from milliseconds to decades due to air currents and temperature change [3]. Therefore, large-scale, long-time, and accurate water vapor retrievals are necessary in weather prediction, climate monitoring, hydrological and energy interchange.