The use of dual-polarisation radar in rainscatter interference studies

Examples of data from the Chilbolton dual-polarization radar are used to indicate the importance of the height of the common volume between the antenna beams and the two services; conditions are identified in which the unwanted/wanted signal ratio can be rendered similar to that for ducting by the effect of interference. It is found that while common volumes centered below the melting height in rain cells can give rise to very low coupling, because of high attenuation, the existence of high reflectivity above the melting height means that much greater coupling is possible.