Mr. Jiafei Xu is currently pursuing the Ph.D. degree with the Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong. His current research interests include the algorithm development for enhancing precipitable water vapor retrievals from multi-satellite visible, near-infrared, infrared, and microwave observations as well as the algorithm validation for various ground-based, satellite-based, and reanalysis-based water vapor measurements