The Quality Control and Gauge Adjustment of C-Band Weather Radar for Royal Rainmaking Operations in Thailand

Weather RADAR has played an important role in weather observation and measuring rainfall for many purposes. It can provide clouds and precipitation information for weather modification activities in several countries. In Thailand, Department of Royal Rainmaking and Agricultural Aviation (DRRAA) has conducted clouds seeding activities since 1969 and used weather radar to evaluate the efficiency of clouds seeding. Because of the quality, weather radar information can influence the success of weather modification mission. This study focused on investigating the impact of radar quality control (QC) and radar rainfall estimation (QPE) with gauge adjustment from C-band weather radar of DRRAA located in Chumphon province in the southern region of Thailand. The radar reflectivity was checked before deployment to retrieve the rainfall amount with ZR relation. The process consisted of clutter identification and the correction of signal attenuation. Thereafter, the radar reflectivity was converted into rainfall depth throughout 24 h. An assessment of the accuracy of the radar rainfall estimate over the study area showed an overall underestimation when compared to the rain gauges.