A simple real-time frequency scaling technique for rain attenuation and its performance

A new algorithm has been proposed for frequency scaling of rain attenuation. It uses the real-time estimates of a spatial variation index in the rain rate profile suggested in simple atmospheric model (SAM) to obtain the scaled attenuation. Measured data are used to validate the algorithm which showed a typical accuracy of better than 2.5 dB for 95% confidence. The time profile of a model parameter derived from measured values has also been effectively utilized to envisage the rain cell movement, particularly for high elevation conditions. Simulated data with predefined rain rate profiles were also used for validations. The relative contributions of the model error and the measurement noise to the final error were obtained. The errors are attributed to the modelling mismatch and intermediate parameter estimation error. The estimation accuracy of the algorithm was found to worsen with reducing elevation. The overall error remains within 3 dB for 0.5 dB of measurement noise and up to lowest elevation of 30 degrees. The simple approach of the model in conjunction with the adequate accuracy makes this algorithm a potential candidate to be used for real-time open-loop fade mitigation.