Processed radar and gauge data

Data are provided in ASCII text files with 3 columns: the first column is the time of observation in UTC, the second is the rainfall intensity in mm/h provided by the gauge and the third is the radar rainfall intensity in mm/h. In total, 6 different radar products are considered. 1) The Danish Stevns C-band single radar product, 2) The Dutch C-band composite, 3) the Finnish C-band composite from the OSAPOL-project, 4) the Swedish BRDC C-band product, 5) the BALTRAD C-band composite and 6) the Danish X-band single radar system in Aalborg. Each file corresponds to a different event. Event selection was done based on rainfall time series from the national networks of automatic rain gauges in Denmark, the Netherlands, Finland and Sweden. Using the gauges, we determined the top 50 rain events (in terms of peak intensity) for each country and observation period. Only events for which both the gauge and radar data were available simultaneously were considered. Also, we imposed the condition that two events for the same location had to be separated by a continuous dry period of at least 6 hours. To increase reliability, all events were subjected to a visual quality control test by human experts, checking both for plausibility and consistency. Cases for which the gauge or radar data were incomplete, obviously wrong or strongly inconsistent with each other were removed and replaced by new events until the total number of events that passed the quality control tests reached 50 for each country. The procedure used to extract the radar data was identical for all countries. First, the 4 radar pixels closest to a given rain gauge were extracted. The 4 radar rainfall time series were then aggregated in time (i.e., averaged) to match the temporal sampling resolution of the rain gauge. Then, for each time step, the value among the 4 radar pixels that best matched the gauge was kept for comparison.