MIT graduate students found a way to dynamically map a city by using the density of cellphone calls, origins and destinations of the calls, and position of users tracked at regular intervals to create computer-generated images that can be overlayed with one another and with geographic and street maps of a city to show the peaks and valleys of the landscape as well as peaks in cellphone use. The pilot city is Linz and anonymous cellphone data are provided by the largest cell phone operator in Austria.

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