The bi-directional POLDER reflectances are normalized using the kernel-driven reflectance model of Maignan et al. (2004). The inversion is carried out over a synthesis period of 30 days with a sliding window of 10 days. More details on the algorithm can be found on the scientific POLDER website. The inversion yields three coefficients : a nadir-zenith reflectance, a geometric and a volumic coefficients. They are used with the angular kernels integrated over viewing directions and over solar directions to calculate the directional and the hemispheric spectral albedo, successively. Values of integrated kernels are specified by CEA/LSCE. The spectral integrations over visible broadband [400 - 700nm], near-infrared broadband [700, 4000nm], and whole spectrum broadband [300 - 4000nm] are then carried out using the 5 narrow bands (490, 565, 670, 765 and 865nm). The conversion coefficients are provided by the team MATIS from CNRM/Météo-France. An algorithmic document is available.

The spectral directional albedo (called Directional-Hemispheric Reflectance (DHR)) is included in the standard "Albedo and Vegetation" product and can be accessible through the POLDER Data Distribution Center.

The spectral albedos (called Bi-Hemispheric Reflectance (BHR)), the broadband visible BHR (BBHR_VIS), the broadband near-infrared BHR (BBHR_NIR), the whole broadband BHR (BBHR), and the broadband visible DHR (BDHR_VIS), the broadband near-infrared DHR (BDHR_NIR), the whole broadband DHR (BDHR) are additional parameters generated by POSTEL. These POLDER-1&2 albedos can be downloaded together with a technical documentation.

One year of POLDER-3 albedos, from July 2005 to July 2006, can be downloaded with an algorithmic and technical documentation. The CNRM, as Expertise Centre for the Albedo product, specified a new retreival algorithm. The validation of the new version of albedo product is in progress.

Albédo directionnel, 670nm, issu de POLDER-3/PARASOL, juillet 2005.