Based on differential absorption method

remote sensing of atmospheric watervapour is discussed in the paper.The water-vapour transmissivity is measured by aspectral radiometer and the water vapour content is obtained by our calculationprogram of infrared-radiation atmospheric transmissivity. The meteorological parametersare observed simultaneously to determine the water vapour content in the path. The result shows that the calculated water vapour content agrees well with the measuredvalue.The correlation coefficient of regression equation is 0.97 and the RMS error is0.015g/cm2.Lastly

the error sources and the way to improve remote sensing accuracyare discussed and the necessity correcting the absorption of other molecule and theextinction of aerosol is indicated.