Animated Flow Maps for Visualizing Human Movement: Two Demonstrations with Air Traffic and Twitter Data

We present a novel flow mapping method called Animated Flow Mapper. Conventional flow mapping uses the thickness of a flow line to differentiate the volume of a flow and arrows to represent the direction. These flow mapping methods have suffered from problems of occlusion especially for visualizing large volumes of data, and when many flows converge at--or diverge from--single points. The Animated Flow Mapper aims to circumvent these problems of occlusion and to provide a more effective visualization of the patterns of the flows. The method uses thin dashed lines of equal width, which are animated to represent the directions and volumes of flows of moving objects by repeatedly redrawing each dashed-line at different speeds. The case studies and results of a human subject opinion survey show the advantages of the Animated Flow Mapper are comparable to other flow mapping methods.