Dr. Liping Di serves as Professor and Director of the Center for Spatial Information Science and Systems at George Mason University in Virginia, USA. He is internationally known for his extraordinary contributions to the geospatial information science/geoinformatics, especially to the development of geospatial interoperability technology and the federal, national, and international geographic information and remote sensing standards. He was one of the core members for the development of the NASA EOSDIS data standards, and is a pioneer in the development of web-based, advanced, distributed geospatial systems and tools. Dr. Di has engaged in the geoinformatics and Earth system research for more than twenty-five years and has published over 500 publications. Dr. Eugene Yu is a Research Professor and the Associate Director of the Center for Spatial Information Science and Systems, George Mason University, Fairfax, Virginia, USA. Dr. Yu received the B.Sc. degree in physical geography from the Peking University, Beijing, China, the M.Sc. in environmental remote sensing from the University of Aberdeen, Aberdeen, U.K., the M.S. in Information Systems and the M.S. in computer science from George Mason University, Fairfax, Virginia, USA, and the Ph.D. in geography with the focus on remote sensing and geographic information systems from the Indiana State University, Terre Haute, Indiana, USA. His research interests include geographic information systems, remote sensing, intelligent image understanding, Sensor Web, semantic Web, computational vision, agro-informatics, and robotics.