Real-time collaborative GIS: A technological review

Collaborative Geographic Information Systems (CGIS) have become an important research area over the past two decades. This paper provides a critical review of the development of real-time CGIS, which is a branch under Collaborative GIS study. A real-time CGIS system provides a multi-user, real-time collaborative work environment, i.e., what you see is what I see (WYSIWIS), for spatial decision support and problem solving. The research about this kind of system has mainly focused on system architecture and modelling, collaborative awareness, concurrent control, collaborative behaviour modelling and other related key issues. The paper presents a two-stage historic development process of real-time CGIS, summarizes major research progress and representative developments by analysing their key technical issues, and based on the review discusses some research problems that need to be solved and some future research directions.