Dong Han received the Ph.D. degree in cartography and geographical information system from the Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing, China, in 2010. From 2010 to 2012, he was a Postdoctoral Fellow in the College of Environmental Science and Engineering, Peking University, Beijing, China. For the past six years, his primary research interest has been in retrieval using DOAS with satellite remote sensing data, ring effect, and retrieval validation with ground-based measurements. His current work is mainly about the applications of satellite remote sensing, including trace gases and aerosols in atmosphere.