Advanced atmospheric modeling with perturbation for VNIR/SWIR hyperspectral data analysis

Models for material reflectance properties, atmospheric effects and hyperspectral sensor properties in the VNIR/SWIR spectral region can be used to predict the detailed spectral structure of spectra to be measured in future field data collections. It is useful to have databases of predicted spectra that span a wide range of possible atmospheric conditions, given that the ambient environmental conditions for a measurement are rarely known in advance. A radiative transfer (RT) code such as MODTRAN® can be used to model the effects of atmospheric propagation in the predicted spectra as measured by a remotely deployed sensor. We are generating a database of optimized atmospheres that considers variations in solar angle, vertical-path-integrated water vapor density, and aerosol and cloud scatterer types and densities. This database provides a large set of discrete atmospheres. To improve the accuracy of the atmospheric spectral functions for a given hyperspectral image, we have developed an atmospheric perturbation model that is based on a rigorous physics-based approach to the variation of the spectral functions that are contained in the database. We will demonstrate how this new approach to atmospheric modeling improves the accuracy of models for VNIR/SWIR spectra collected with a space-based hyperspectral sensor.