A Method of Acquiring BRDF of Objects in the Field
一种获取野外实测目标物BRDF的方法

The bidirectional reflective characteristic of objects plays an important role not only in models of remote sensing but also in inversion,consequently,it is the base of quantitative analysis in remote sensing that chooses the appropriate method of acquiring the bidirectional reflective characteristic of ocjects in natural environment.For a long period,BRF(Bidirectional Reflectance Factor) acquired in natural environment is taken as the expression of bidirectional reflective characteristic of objects,but the definition of BRF doesn't prescribe radiant circumstances explicitly.Actually,BRF acquired in natural environment is related to radiant environment,so it is unsuitable to describe the reflective characteristic of objects with BRF.This viewpoint is testified in this paper by field data,meanwhile,we established the truth that BRDF(Bidirectional Reflectance Distribution Function) has nothing to do with the radiant environment.This paper provides a new method of acquiring BRDF data of objects in natural environment in order to arouse more pondering over the difference between BRDF and BRF.As it is indicated in the result of the experiments,with this method,we can acquire BRDF of objects in natural environment exactly.