OBSERVATION OF THE RAINDROP SIZE DISTRIBUTION WITH A NEWLY-DEVELOPED LASER RAINDROP GAUGE

Abstract

A new type laser instrument for measuring the size of raindrop, called a laser raindrop gauge hereafter, is developed. This gauge can measure the minutely rainfall intensity besides the raindrop size distribution. The observation has been carried out at the campus of Chuo university in Tokyo for two years. It is concluded that the relationship between the radar reflectivity factor and the rainfall intensity can be treated as approximately constant during a rainfall event. If the radar parameters, B and β for a rainfall event are decided by the laser raindrop gauge, the rainfall intensity with radar raingauge can be estimated more accurate than by the conventional methods proposed formarly.