The Atmospheric Correction for TM Image under Complicated Geographic Conditions Based on Automatically Extracted Many Dark Objects

Under complicated geographic conditions,the spatial distribution of aerosol is comparatively significiant.It is hard to achieve desirable result only by using measured parameter of Aerosol or Dark Objects to carry out the atmospheric correction.Moreover,manually selecting dark objects requires sufficient expertise.Program is used to automatically find out dense vegetation pixels and vegetation pixels under shadow in mountainous areas as dark objects,which are evenly distributed in different district and evaluation,as many as possible.Next,a good imitation was made for complicated geography of atmospheric condition.Based on the radiative transfer model,some mathematical methods such as iteration and interpolation are used to obtain the optical depth of TM1 and TM3 bands.Then,the aerosol wavelength exponent and turbidity coefficient are calculated.Finally,the atmospheric optical depth of each band is calculated to implement the atmospheric correction.