| Despite a recent surge in research, cartographic animations remain a frontier area in Geography. As late as 1990, authors such as Campbell and Egbert bemoaned the lack of development of temporal mapping techniques. They point to pioneering work by Thrower (1959), Tobler (1970), and Moellering (1980, 1984) as evidence of the promising future animation holds, but note it has not yet come to pass. Recently, animation in cartography has been researched more thoroughly. Yet, articles resulting from this research tend more towards the theoretical, and less towards an explanation of specific development techniques. This research answers the challenge set down by Campbell and Egbert to develop new methods for visualizing spatio-temporal data, and, in the process, leads to the development of a new technique for creating three-dimensional animations. I will describe the construction of the animations in detail in the hope that others pursuing similar goals can use the techniques described. The animations are employed to show U.S. population density change by county from 1790 to 1990. An expert panel of professional cartographers, through the use of a questionnaire, informally reviewed the animations. The results of the questionnaire support animation as a technique and warrant continued research into the both the two and three-dimensional animations. |
