Local Random Errors in Tipping-Bucket Rain Gauge Measurements

This study presents empirical analysis of the errors in tipping-bucket rain gauges that manifest themselves as random differences between closely collocated instruments. It is based on a substantial data sample from 15 collocated rain gauges. The errors are shown to be considerable and highly dependent on rainfall intensity and timescale. These dependencies are estimated using nonparametric regression. Strong dependence of the errors on the data collecting and processing strategy is also demonstrated. An analytical model and estimates of its coefficients are provided to concisely quantify the results in different scenarios. Finally, possible improvements of the accuracy and reliability of the surface rainfall measurements are discussed.