20 
(3) , 
where Ç , rj are the standardized slope components and Z,, Z u are the slope components along the 
crosswind (Z c ) and upwind (F ) directions , respectively. Furthermore , a , a are the root mean 
squares of Z c , Z u , respectively. The explicit dependence of a , cr u and c on the wind speed is 
given by Cox and Munk [1]. The relationship between the surface slope angle ¡5 and its X c ~, Y u - 
components is given by Eq.(4). 
The sea surface reflection function is composed of a reflection function specifying the radiation 
reflected directly by the sea surface , and a water column reflectance which is the transmitted 
radiation from the sea. In other word, it is the radiation reflected diffusely by water molecules and 
hydrosols within the sea. It is very difficult to evaluate the under water radiation, because of many 
uncertainties in estimating the underwater radiative transfer model. In this paper we assume that 
the water column reflectance can be expressed by r wc , for the simplicity. The angular dependence 
of r wc may be neglected because of the observational difficulty in the measurements and r wc may be 
a few percent in the short wavelength (0.45pm) , whereas it is very close to zero in the near 
infrared (0.85pm) [7] . Then , according to the formulation by Takashima [5] with some 
modifications of his original form , the sea surface reflection R sf can be given approximately by 
where Rot(a) is the rotation matrix for a given rotation angle a and it is given in Eq.(6) . The 
angles , 6 and y are the rotation angles defining the reflection function with respect to the local 
(4) . 
Eq.(5). 
R sf(^ = 4 cog4 p Rot{ô )R sp (2ü))Roî{y ) + r wc 
(5) ,