Potential and Limitations of Filling Gaps in Commercial Microwave Link Data Stemming From Complete Loss of Signal During Heavy Rainfall

Rainfall estimates from commercial microwave links (CML) can be impaired by the total loss of signal during heavy rainfall events. This implies that the highest rainfall intensities may not be observed by CMLs during these so-called blackouts. As CML rainfall estimation approaches an operational state, this issue has to be studied and potential mitigation strategies have to be developed. Therefore, we investigate three methods which fill blackout gaps detected by a filter established in previous work. The methods we developed consisted of a linear and a cubic interpolation as well as the infilling of the values at the detection limit of each CML. In general, the linear interpolation underestimated and the cubic interpolation overestimated rainfall intensities compared to a reference. The physically motivated infilling at the detection limit performed best. In conclusion, blackout gaps should be mitigated with one propose methods to improve the quality of rainfall estimates derived from CMLs.