  The radiation emission spectra of polarized photons emitted from charged
particles in single oriented crystals are obtained in Bayer-Katkov
quasiclassical approach. The results of numerical calculations are presented in
the region of small angles of incidence for which the coherent theory fails but
magnetic bremsstrahlung region isn't yet achieved. The spectral distribution of
linear polarization degree repeats, in general, the form of the intensity
distribution. At sufficiently small angles, in the case of planar orientation
of crystal, there is a wide maximum of essential linear polarization at low
frequencies.
