In this paper

methods of retrieving total column water vapor by using sun photometer are described in detail

which include single-channel method and double-channel method

and the latter can be achieved by using different non-water channel.The influence of aerosol optic depth and Rayleigh are considered

and the data acquired by radiosonde are used as true value of total column water vapor.Analysis on errors shows the retrieved results are very close by using varied methods.In practice

each method can be equally used to retrieve columnar water vapor content.