ИСТИНА

A method is presented for measuring frequency dependence of reflection coefficient for a flat surface with non-ideal boundary conditions irradiated from oblique incidence direction. We use MLS method and a monopole source for measuring impulse responses of a surface for a set of angles of incidence. Then, to convert the results into the flat wave reflection coefficients, the Fourier-Bessel integral is inverted, i.e. an integral equation is solved numerically. The presented method is supposed to be more informative than the reverberation room method that works for diffuse field. The new method is competitive with the impedance tube method, which works only for normal incidence. The frequency dependencies found by the new method are compared with the ones theoretically calculated using Biot theory for appropriate surfaces. The work is supported by the Scientic Schools grant 7062.2016.2.