Abstract: Tracking systems and methods of estimating a distribution of persons in a physical environment are provided. A tracking system may comprise a wireless receiver configured to detect instances of a wireless signal from each mobile device passing through an entryway in and out of the environment and a computing device configured to identify an identifier transmitted in each instance and compute a trip time for each mobile device and an aggregate trip time spent by all mobile devices during an analysis period. The computing device may read a probability map that indicates a probability that one of the mobile devices is located in each predetermined location and oriented in a predetermined direction. The computing device may assign each time unit a predetermined location and orientation based on the probability map, and for a selected target location, compute and display an aggregate time and a probability distribution of shopper orientation.