Wind turbine backscatter modeling and analysis in a networked weather radar environment

The continuing expansion of wind energy industry has led to the installation of several wind farms which are often in the vicinity of the weather radars. This is a source of growing concern for the weather radar community since the wind turbine echo contaminates the radar returns from the precipitation. The wind turbine tower can drive the receivers into saturation and the Doppler shift from the moving blades can introduce additional clutter in the estimation of wind speed, reflectivity and rainfall rates. The radar cross-section of the wind turbines has a large temporal and spatial variation which cannot be removed by traditional clutter filtering algorithms.

In this paper, we present a model for theoretical analysis of the radar signature from a wind turbine based on the radar cross-section computations. This model is then compared with the return signals from a wind farm when observed in a networked radar environment. For ground- based radars, the echoes from identical wind turbine models vary with the location of the plane of rotation of blades relative to the radar beam. This difference in the observed signal from different radars in the network while observing the same wind turbine is then explained in this paper through the mode computations. The difference in the observed signal from different radars while observing the same wind turbine is then explained in this paper through the mode computations.