# Program for calculating transmittance of grating smart windows and calculated data

## Description

A program for calculating transmittance of grating smart windows and calculated data for all possible values and signs of calculated parameters are presented. Design of grating optical filter for smart windows and all equations for calculating its parameters are described in [Zakirullin RS, Odenbakh IA. Simulating annual autoregulation of daylight by grating smart window with angular-selective transmission. J Build Perform Simul. https://doi.org/10.1080/19401493.2023.2256690]. Results of numerical simulations are presented in 8 Microsoft Excel 2019 files named, for example: program+-35+-30.xlsx The first number in the file name means the slope angle of the gratings, the second number means the difference between the azimuths of the Sun and the window A-Aw. Combinations of signs of these angles in the file name mean, in this example: ++ or --. Each Microsoft Excel file contains next columns: Time (this column is empty, for real calculations it is necessary to set the time) h, deg (the elevation of the Sun at set the time) А, deg (the azimuth of the Sun at set the time) A-Aw, deg (the difference between the azimuths of the Sun and the window) , deg (the incidence angle of the solar beam) x, mm (the coordinate of the trace of the point of incidence solar beam onto the input gratings surface, left on the output gratings surface) y, mm (the coordinate of the trace of the point of incidence solar beam onto the input gratings surface, left on the output gratings surface) , deg (the projection of the incidence angle onto the plane orthogonal to the gratings orientation) , mm (the shift between the traces of the input gratings on the output gratings surface at the characteristic and arbitrary incidence angle) cor, mm (the corrected shift) teor#c (the theoretical transmittance of a filter with different strip widths) cor#c (the corrected transmittance of a filter with different strip widths) teor=c (the theoretical transmittance of a filter with equal strip widths) cor=c (the corrected transmittance of a filter with equal strip widths) teor-c (the theoretical transmittance of pure glass) cor-c (the corrected transmittance of pure glass)