NEW ATMOSPHERIC CORRECTION METHOD BASED ON BAND RATIOING

Abstract

The Atmosphere plays a central role in the reflectance of the Earth and contributes an additive path radiance term that will cause an error in the sensor readings of the data acquired by the satellite. it is necessary then to get rid of the atmospheric effect to retrieve the actual surface reflectance. Atmospherically corrected surface reflected images improve the accuracy of surface land use and Earth's reflected data. The problem to estimate surface reflectance is the assessment of the path radiance. In this paper, characteristics computation was based on the dark object theory; the atmospheric parameters are considered in regions were the absorption is maximal. Histogram satellite image has been used the correction factor; i.e. histogram peak value was adopted. Histogram mean and standard deviation are also used for the path radiance estimation. For the image bands in the visible spectrum, water areas involve some non-zero DN value. These non-zero DN values are adopted to represent the path radiance. The most probable "histogram-peak" is introduced to overcome the problem of non-zero existed values.
As a fidelity test, regions that have been considered to represent the path radiance are classified and isolated from other image regions. The degree of correlation between isolated image regions has been considered to satisfy the method for path radiance estimation. Eigen values and covariance matrix of the principal components have been used for this qualification test.