CPBAC: A quick atmospheric correction method using the topographic information

Topography is one of the most important factors that can affect the radiative transfer process in remote sensing earth observation by making the ground objects of the same type but in different topographical locations present different radiative characteristics which increases the complexity of spectral radiation information and violates the radiometric consistency among those type-identical objects. Utilizing the topographic information we proposed a coupling parameter based atmospheric correction method or CPBAC for short. This method firstly establishes the radiative transfer equations using the data of objects with good Lambertian properties under various topographical positions, and then calculates the coupling parameters of atmosphere and topography and finally accomplishes both the atmospheric and topographic correction simultaneously using those parameters. To validate it, the Landsat 7 multispectral data about one region in Cody Town of Wyoming, USA which was acquired in different seasons was used to do a comparison with the commonly used FLAASH and QUAC methods. The comparison revealed that the CPBAC method can effectively achieve atmospheric correction with its result similar to that produced by either FLAASH or QUAC, and the topography caused spectral radiation difference among the objects of the same type was eliminated by showing an increased spectral consistency and a decreased relevance between radiometric information and topography. Although the assumptions which the CPBAC method is based upon impose restrictions on its widespread use, it can achieve the best effect when it is applied to handle the data containing objects of good Lambertian properties located in different terrains, and the selected pixels for the parameters calculation are various combinations of those with small slope and small sun zenith angle.