Abstract: By using the two-channel ratio arithmetic,the three-channel ratio arithmetic and the improved Jiang's three-channel ratio arithmetic,the vapor content of atmosphere was retrieved based on MODIS data in Heilongjiang Province.The retrieval precision was validated by using sounding real-measure data.It was indicated that the results retrieved by the two-channel ratio arithmetic were the best.The correlation coefficient between calculated results and the real-time measured data was 0.9664.The results retrieved by the three-channel ratio arithmetic took the second place.The relevant correlation coefficient was 0.939.The results retrieved by improved Jiang's arithmetic was the worst.The relevant correlation coefficient was 0.8358.The time change characteristic of the vapor content of atmosphere retrieved by the two-channel ratio arithmetic accorded with the seasonal climate change characteristic in Heilongjiang Province,while the spatial change characteristic accorded with the actual circumstance that the vapor gross above water body was bigger than it above land.Consequently the two-channel ratio arithmetic was a suitable retrieval method in Heilongjiang Province.

Key words: MODIS, MODIS, Vapor content of atmosphere, Retrieval