The simulation of forward and backward hydrometeor scatter interference using dual-polarisation radar data

Examines one aspect of the CCIR model, namely the difference in transmission loss between forward and back scatter statistics. This difference is predicted by the model at low time percentages because of the difference in path attenuation inside the raincell. For the back scatter case, the transmission loss includes contributions from the scatter off the near-edge of the rain cell, which suffers very little attenuation within the cell itself. This contribution increases in importance for higher rain rates. The corresponding contribution for the forward scatter, however, will always include this component of attenuation, the magnitude of which generally increases with rain rate, and it is this factor which causes the predicted forward scatter transmission loss to be significantly higher than the back scatter transmission loss for high rain rates. The predicted asymmetry is examined by simulating hydrometeor scatter events using the data obtained from the 3 GHz dual-polarisation radar at Chilbolton in Hampshire UK