Two-dimensional full-wave simulations of radial correlation Doppler reflectometry in linear and non-linear regimes

The technique of radial correlation reflectometry both conventional and Doppler is studied using a two-dimensional full-wave code in extraordinary mode of propagation. Linear and non-linear regimes are considered for a wide range of antenna tilt angles and radial correlation lengths. The radial correlation length Lr computed from the amplitude, the complex amplitude and the complex phase signals are shown for each particular case. The numerical results show that the measurement of the turbulence radial correlation length with microwave reflectometry is challenging. It is shown that in most cases the radial correlation length as measured by microwave reflectometry is different from the turbulence radial correlation length. In the linear regime the results show that conventional reflectometry overestimates the radial correlation length in agreement with theory. It is shown that Doppler reflectometry provides a good estimation for Lr if the antenna tilt angle θ is properly scanned. In the non-linear regime both conventional and Doppler reflectometry provide similar Lr values regardless of the antenna tilt angle, but these values are shorter than the turbulence radial correlation length.