A method is described for incorporating surface-emitted surface-reflected (SESR) radiation into the infrared emissivity calculation for an anisotropic wind-roughened sea surface slope distribution model that depends on both wind speed and direction. First, the direct emissivity is obtained by ignoring the SESR radiation. Then, the first order SESR emissivity is obtained by using the direct emission as a radiation source. Finally, the ith order SESR emissivity (i ≥ 2) is recursively obtained by using the i-1st SESR emission. Sea surface emissivity up to the second order is calculated for wavelengths of 3.7, 11, and 12 μm at wind speeds of 3, 5, 10, and 15 m/s.
   Sea surface emissivity derived from the isotropic slope distribution model, which depends only on wind speed, is widely used in radiative transfer models, and validations have been performed through comparisons with measurements. This study examines the applicability of sea surface emissivity calculations to remote sensing measurements with respect to wind speed, emission angle, and the required accuracy of sea surface temperature, by use of sea surface emissivity derived from the anisotropic slope distribution model as a reference. For example, the sea surface temperature accuracy was better than 0.3 K for emission angles below 68° and 56° for isotropic slope distribution models with and without SESR radiation, respectively, for a wavelength of 11 μm, wind speed of 10 m/s, and sea surface temperature of 288 K.
   The isotropic model without SESR radiation performs well for satellite remote sensing data up to an emission angle of at least ∼50° provided the wind speed is less than ∼10 m/s. Ground based measurements with emission angles larger than 70° could be improved using the anisotropic model with SESR radiation.