Chapter 19
REMOTE SENSING OF ALBEDO USING THE
BRDF IN RELATION TO LAND SURFACE
PROPERTIES
W. Lucht(1), C. Schaaf(1), A. H. Strahler(1) and R. d’Entremont(2)
(1) Center for Remote Sensing, Boston University, Boston, USA and (2) Atmospheric and
Environmental Research, Inc., Cambridge, USA.
1.
INTRODUCTION
Albedo characterizes the radiometric interface of the Earth’s land surface
with the atmosphere. It is defined as the fraction of downwelling solar shortwave radiation reflected back into the atmosphere from the surface. The
numerical value of land surface albedo depends mainly on two things: the
optical properties of the surface and its three-dimensional spatial structure.
The question to be investigated in this paper is the following: Given that
albedo may be retrieved from space using multiangular remote sensing data
through the inversion and integration of a bidirectional reflectance
distribution function (BRDF) model, can the magnitude of albedo and its
dependence on solar zenith angle be related to land surface optical and
structural properties?
2.
THE ROLE OF ALBEDO IN THE GLOBAL
SYSTEM
Land surface albedo plays an important role in the global
biogeochemical, meteorological and climatological system for the following
three reasons.
175
M.M. Verstraete et al. (eds.), Observing Land from Space: Science, Customers and Technology, 175–186.
© 2000 Kluwer Academic Publishers. Printed in the Netherlands.