i Detection of Smoke and Dust Aerosols Using Multi-sensor Satellite ...

Sun Satellite
Figure 3.2: Basic radiative transfer model
Based on the fundamental radiative transfer model (Liou, 2002; Li et al., 2001), the
reflectance at TOA viewed from a satellite can be expressed as in Eq. 3.1.
r( ; , ; , ) t( ; ) r ( ; , ; , ) t(
; )
0 0 0 s 0 0
rs
rg
r ( ; , )
t t t
g 0 0 *
( ; 0 )exp exp ( ; , ) ( ; )
* s
0 1 rs ( ) rg
( )
r ( )
t t t t
g
*
( ; 0 ) s ( ; 0, 0 ) exp ( ; , ) ( ; )
* s
1 rs ( ) rg
( )
22
Smoke (dust)
Ground
(3.1)
where λ is the wavelength and τ is optical depth of smoke layer. Two parameters, μo and
μ are the cosine of the solar zenith angle and view angle. t (λ, μo) is the transmittance
from the top of atmosphere to smoke and t (λ, μ) is the transmittance in inverse direction
in the view direction of satellite. Two azimuth angles, фo and ф, are viewed from sun and
satellite, respectively. In Eq. 3.1, the notation asterisks indicate that these quantities are