1Sing the 
Op of the 
, 2nd, and 
Ititude of 
? and the 
tribution 
nge type 
(7) 
Ir = land 
ım in the 
with v= 
radiation 
y = 0.0at 
e indices 
.5-i0.05: 
ds ( from 
m/sec), 
ndex and 
:d and its 
ne of the 
, 1.5, and 
1erosols, 
ions, 135 
eoretical 
e data or 
Wz220 
retically 
range of 
We found 
observed 
ed. They 
d mers 
SVE 
ve aerosol 
h v=40 
r 11.0m/ 
.33-10.0] 
< 12.50 
e aerosol 
vords, the 
models, 
when an 
he Junge 
type models with v « 3.0 and v » 5.0 can not satisfy the observed 
reflectance data. 
The case of the aerosol model A (v 2 3.5 and m-1.5-i0.01 ) is 
presented here in detail, because of two reasons: (1) an Ángstróm 
coefficient a=1.5 obtained from the aerosol optical thickness 
measurements ( T=0.12 at 0.85um and 1 =0.314 at 0.45um ) 
suggests V = 3.5, according to Angstrôm's law, namely, v = 042, 
(2) The refractive index of typical aerosols, like dust and water 
soluble particles, is m=1.5. The surface wind speed does not change 
the shape of the reflectance curve in the back scattering direction, 
but it affects that in the sun glitter direction ( at the viewing zenith 
angle between -30° to -50° ). We can estimate a range of wind 
speed from the sun glitter portion of reflectance curve in the case 
of aerosol model A. The range of the wind speed was thus 
estimated to be 10.5 m/sec = V = 13.5 m/sec from Fig.1-(a), 
whereas the observed one is V=14.4 m/sec. As shown in Fig.1- 
(b), the wind speed has little effect on the linear polarization. The 
theoretical reflectance and polarization curves of the aerosol model 
A for V=11.0 m/sec are shown in Figs.2-(a) and 2-(b), together 
with those of the aerosol models with m = 1.50, and m=1.50- 
i0.05. We obtain the best fit with the observed reflectance data in 
the case of m=1.5-10.01. However, theoretical linear polarization 
values in the back scattering direction are much smaller than the 
observed ones in the aerosol model A case. As shown in Fig. 2- 
(b), the case of larger amount of aerosol absorption (mz1.5- 
10.05) gives better results in linear polarization than other two 
cases. The reflectance data suggests a model with slight absorbing 
aerosols , whereas the linear polarization data suggests that with 
strong absorbing aerosols. This is a contradiction and we need 
more detailed analysis on this point near future, as well as the 
foam effects which were not taken into account in this study. In 
any cases, we found that the candidate aerosol models which are 
derived from the reflectance analysis have some difficulties to 
satisfy the observed linear polarization data in the backward 
scattering direction. 
3. CONCLUSIONS 
In this paper we have made an analysis of Medimar airborne 
POLDER data over the sea by the multiple scattering model. Our 
conclusions based on this study are summarized as follows: 
(1) We found several Junge type aerosol models, A-E which can 
satisfy the observed reflectance data at 0.85um in the principal 
plane by examining various combinations of aerosol optical 
parameters and wind speeds. 
(2) It is possible to estimate the surface wind speed by examining 
the reflectance surge in the glitter direction at 0.85um . The 
estimated ranges of the surface wind speed were presented for the 
aerosol models, A - E. It was found to be 10.5 m/sec < V € 
13.0 m/sec in the aerosol model A (Junge type size distribution 
With v = 3.5, and refractive index m = 1.5 - 10.01) which is the 
339 
most probable model among the candidate aerosol models 
suggested from the reflectance analysis at 0.85um . 
(2) However, we also found that none of these models can satisfy 
the observed linear polarization 
data in the back scattering direction. 
(3) Further study on other types of aerosol size distribution function 
are needed to find a aerosol model which can satisfy both the 
reflectance and polarization data. 
REFERENCES 
[1] Deschamps,P.Y .,Bréon,F.M., Leroy, M., Podaire,A., Bricaud, 
A., Buriez, J.C., and Seze, G. , “The POLDER Mission: Instrument 
Characteristics and Scientific Objectives," IEEE Trams. on GRS 
, vol. 32, No.3, pp. 598-615, 1994. 
[2] Bréon, F.M. , and Deschamps, P.Y. , *Optical and Physical 
Parameter Retrieval from POLDER Measurements over the Ocean 
Using an Analytical Model," Remote Sensing. Environ , vol. 43, 
pp. 193-207, 1993. 
[3] Cox,C. and Munk,W. , “Measurement of the Roughness of 
the Sea Surface from Photographs of the Sun’s Glitter,” 
J,Opt.Soc.Amer. vol. 44, pp. 838-850, 1954. 
[4] Hansen,J.E., and Travis, L., “Light Scattering in Planetary 
Atmospheres, “ Space Sci. Review , vol. 16, pp. 527-610, 1974. 
[5] Kawata, Y., Yamazaki, A., Kusaka, T., and Ueno, S. , ^Aerosol 
Retrieval from Airborne POLDER Data by Multiple Scattering 
Model," Proc. of IGARSS' 94, vol. 4, pp. 1895-1897, 1994. 
[6] Junge,T., "Aerosols," in Handbook of Geophysics. (Eds. 
Campen et al.), Macmillan, New York, 1960. 
[7] Takashima,T. and Masuda,K. , "Degree of radiance and 
polarization in the upwelling radiation from an atmosphere-ocean 
system," Appl. Opt. , vol, 24 , pp. 2423-2429, 1985. 
[8] Takashima,T., “Polarization Effect on Radiative Transfer in 
Planetary Composite Atmospheres with Interacting Interface,” 
Earth, Moon, and Planets , vol. 33, pp. 59-97, 1985. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996