Nowcasting of the Spatiotemporal Rain Field Evolution for Radio Propagation Studies

This paper presents a nowcasting method capable of short-term forecasting the spatiotemporal rain field evolution, based exclusively on the analysis of radar reflectivity data without any a priori assumption on its spatial structure. The method has been developed to be integrated into future foreseen propagation impairment mitigation techniques, which take advantage of the temporal and spatial variability of rain in order to improve significantly the capacity and performance of the next-generation radiocommunication networks, operating at frequencies above 10 GHz . The rain field database used for assessing the nowcasting method consisted of 746 radar images collected by the weather radar located at A Coruña (Northwest Spain) during 25 rain events. The proposed method is made up of three main parts: a procedure that estimates the rain field displacement between two consecutive weather radar images, an algorithm that makes predictions for the next rain field displacement, and an operation that shifts the rain field according to the forecast displacement. The forecast quality of the developed method has been assessed by means of six skill indices common in the literature. Results reveal that the nowcasting method achieves a reasonably good forecast skill.