Solar radiation enters the Earth's atmosphere with a portion being scattered by clouds and aerosols.

Processing, archiving and distributing Earth science data
at the NASA Langley Research Center

How do I convert data in the L1B2 products to top-of-atmosphere bidirectional reflectance factor (BRF)?

Since November 2002 (product version 0016 and later), the MISR L1B2 products contain parameters within the file that make it easier to convert to BRF. The BRF conversion factor for each band is derived from the equation:

(pi * SunDistanceAU2) / (std_solar_wgted_height * cos(SolarZenith))

This factor can be used to calculate the BRF:

BRF = BRF conversion factor * Radiance

The Radiance may be obtained from the Radiance/RDQI by right-shifting 2 bits, then multiplying the result by the Scale factor (radiometric) contained in the Radiance Grid Metadata.