In the atmospheric research by satellite remote sensing

due to the inhomogeneous pixels of land surface

there are some limitations of the present algorithms in the reflectivity retrieve of the earth’s surface

which are used in deducing the oceanic surface reflectivity and the aerosol optic thickness above it.Now these limitations can be removed by the three-step approach.The algorithm of three-step approach was introduced;the earth’s surface reflectivity of Chiba was retrieved after the atmospheric correction and effect removing of the neighboring pixels to the ASTER satellite data.The distribution of the aerosol optic thickness was then retrieved from the earth’s surface reflectivity.The earth’s surface reflectivity in the fair weather days was applied to retrieve the aerosol optic thickness of the other days in the same season

which not only reduced the effect of the choice of aerosol model but also realized the deduction of the aerosol optic thickness distribution without the data from the sun photometer.