Estimation of bidirectional reflectance distribution function from land surfaces using airborne POLDER data

This paper shows the estimation of the bidirectional reflectance distribution function (BRDF) using the airborne POLDER image data. The BRDF is an intrinsic measurement of directional properties of the Earth's surface. The estimation of BRDF requires many remote sensing measurements of a given surface target from different viewing angles. The airborne POLDER sensor has a capability of measuring successively reflected radiation by terrestrial surfaces in a framed image from different viewing angles during a single aeroplane pass. In this study we have analyzed a subset of the airborne POLDER data over lands obtained in the so-called La Crau campaign conducted by Centre National d'Etudes Spatiales (CNES), France in 1990 by using the multiple scattering theory. The airborne POLDER data is converted into the albedo data by using our atmospheric correction scheme and then the accurate BRDFs for selected surface covers are estimated. The estimated BRDFs show an anisotropic reflection law is valid for vegetated surfaces at 850 nm and fitting parameters for their BRDFs are presented in this paper.