ИСТИНА

Diffraction of plane wave on a 3-dimensional periodic layer is considered. The layer has arbitrary permittivity distribution and is bounded by two surfaces, that have arbitrary shape. The method of projections is used. It allows to reduce the initial problem to the system of first order ordinary differential equations. The corresponding computer program is written. It is verified by comparison with simple cases, that allow analytical solution, and with the two dimensional case of E-polarized or H-polarized plane waves. Some calculations for the needs of sea surface radiometry are performed.