What is Albedo?
Albedo is the degree in which an object reflects light, specifically as the ratio of specific to reflected electromagnetic radiation. In terms of albedo of the earth’s surface, a better definition of albedo is in terms of the solar radiation budget, that it represents the ratio of solar radiation reflected to total incoming solar energy. Global data sets of surface albedo products can be obtained from satellite data. Remote sensing data can reach stunningly detailed resolution, as detailed as tens of meters. The data used in this project are from NASA MODIS Aqua and Terra satellites.
The description from their website:
“MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Terra's orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth's surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths (see MODIS Technical Specifications). These data will improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.”[1]
Data Processing
MODIS 
uses a kernel based bidirectional reflectance distribution function that splits the surface of the earth into pixels, where the data for each is actually an average across the swath of area. The data products that are supplied by NASA are not finished albedo itself, but base parameters that can be used to derive blue sky albedo. Other inputs must be used for calculation, including the solar zenith angle of the sun and the atmospheric optical depth. From the parameters, two separate versions of albedo are calculated representing two extremes, one that assuming the entire light source to be directional (black-sky albedo), and another assuming that it is all diffuse (white-sky albedo). Actual blue-sky albedo is an interpolation between the two using with the fraction of diffuse skylight at the time of the measurement.
- http://modis.gsfc.nasa.gov/about/
- img. http://bhanderi.dk/research/albedo/