Investigating the Role Of ZTD and Cloud Top Properties for Rainfall Detection

Global Navigation Satellite System (GNSS) measurements can provide Zenith Tropospheric Delay (ZTD) values with high temporal resolution and precision, making them valuable for studying meteorological phenomena, especially precipitation events. In this study, we estimated ZTD using data from a GNSS station located in Patna. We also utilized cloud top properties, such as cloud top temperature (CTT) and cloud top pressure (CTP), over the Patna region for rainfall monitoring. Based on the observations, we developed an algorithm using ZTD values in conjunction with CTT and CTP, highlighting the importance of ZTD. The results show a True Alarm Rate (TAR) of 84.6% and a False Alarm Rate (FAR) of 55.9% when ZTD is not considered. However, when ZTD values are included, the TAR is 82.3%, and the FAR decreases significantly to 34.5%, representing a notable reduction in FAR by 21.4%.