Visualization of Spatio-Temporal Information Based on Transparency

Based on the transparency visual variable in electronic map,we present a spatio-temporal visualization method that considering time focus and context.The method represents normally the spatio-temporal contents at the time focus as well as visualizes the objects in the user-defined time context by graphic elements with different transparencies simultaneously.It not only provides more spatio-temporal information with the same map extent,but also depicts the temporal distributions and temporal relationships of phenomena.