A Pulsed Interference Model for Weather Surveillance Radars

Abstract Electromagnetic interference can contaminate weather radar data, and it is more likely to occur in the future due to increased commercial use of the electromagnetic spectrum. To gain a better understanding of the impact of interference on radar data quality and to support the development of electromagnetic interference filters, a high-fidelity interference simulator for weather radar is needed. In this paper, we focus on pulsed interference from surveillance radars that can manifest as either direct- or indirect-path interference. Direct-path interference can occur when the interfering radar is in the line of sight of the receiving radar. In contrast, indirect-path interference occurs when the signal from the interfering radar scatters off hydrometeors and can cause contamination without being in the line of sight. The weatherlike characteristics of indirect-path interference can make interpreting radar data difficult for operational forecasters. We developed a model for both direct- and indirect-path interference based on our examination of actual instances of interference in WSR-88D data. Our model accounts for changes in radar parameters and scanning strategies that produce corresponding changes to the interference pattern. This model will allow forecasters to assess the spatial effects of pulsed interference at varying power levels, and it can also be used to evaluate the effects of pulsed interference on forecasts, algorithms, and filter performance in future studies.