Temporal Coverage: March 2000 - present (Monthly)
The MISR DHR Average layer displays global directional-hemispherical reflectance (DHR) of MISR’s red, green, and blue bands averaged on a monthly basis. DHR, also known as the “black sky albedo,” is a unitless measure of the radiance reflected from the Earth’s surface under illumination from a single direction—in other words, it represents the reflectance off the Earth’s surface that would be measured if Earth had no atmosphere causing scattering of the Sun’s light. It is calculated by taking the integral of the bidirectional reflectance factor (BRF) over the hemisphere being viewed; BRFs are calculated from MISR data by multiplying the radiance measured in the red, green, and blue bands of MISR’s cameras by a conversion factor that accounts for the view angle of the camera and the solar zenith angle. DHR is used to study the behavior of the atmosphere closest to the surface (the boundary layer) as well as in studies of the Earth’s radiation budget.
This layer is produced from the DHR_average field of the MISR Level 3 Component Global Land Surface Product, which is turn a compilation of the MISR Level 2 Land Surface LandDHR field. It is available globally over land only on a monthly basis, with a spatial resolution of 0.5 degrees latitude by 0.5 degrees longitude. Coverage may be limited in areas with frequent cloudiness.
References: MISR Level 3 Component Global Land Surface Product