Diffraction effects in residual error of dual-frequency global navigation satellite systems

Influence of diffraction effects in a turbulent ionosphere on accuracy of dual-frequency global navigation satellite systems (GNSS) is considered. The residual error is calculated in the geometrical optics (GO) approximation with the use of the second approximation for an eikonal. The second-order Rytov approximation is used for taking diffraction effects into account. Numerical simulation of the residual error bias and variance is carried out. It is shown that, except for low angles of satellite elevation, we can neglect diffraction effects when evaluating residual error of the multiple-frequency GNSS.