Abstract
The field of Intelligent Transport Systems, including the autonomous cars, has drawn great attention to information of weather forecasting. For efficiently navigating a moving vehicle to a safer route, it is urgent to detect big drops in the sky earlier before forming a localized heavy rainfall. This study aims to propose a new method based on estimating the median of raindrop size distribution from the observation of X-band polarimetric radars. Then, this method utilizes to verify the lead time of big drops detected in the sky before reaching the ground. As a result, we have fitted data included large raindrops with a new curve for estimating the median of raindrop size distribution using differential reflectivity calculated by 2DVD data. In addition, according to case study of localized heavy rainfall events, big drops can be detected at the height of 500 m using the three-dimensional data of polarization parameters in XRAIN, which is more than 5 minutes earlier than rain gauges recorded the corresponding rainfall. This result has testified the possibility of early detection of a heavy rainfall by using the observation of XRAIN.
