Using 3D information for atmospheric correction of airborne hyperspectral images of urban areas

In this paper the benefits of using 3D data on surface elevation of urban areas are investigated to compensate airborne hyperspectral images for atmospheric effects. The strong relief that is characteristic of most cities due to buildings and other 3D objects results in radiative effects that are not taken into account by classical atmospheric correction methods considering a flat surface. The algorithm ICARE-HS (Inversion Code for urban Areas Reflectance Extraction using HyperSpectral imagery) overcomes this limitation using 3D data on the surface coming from lidar or stereoscopic imagery. A digital surface model of the urban area is combined with ray tracing techniques to simulate relief-related radiative effects such as shadow casting and multiple reflections between objects. In this paper ICARE-HS is applied to airborne hyperspectral data of the city center of Toulouse, France, which are also processed by a standard 2D correction method for comparison.