Transition detection

Abstract

A computer implemented method () of determining a location of one or more transitions (-) on a map and/or the time at which one or more transitions (-) occurs, the one or more transitions (-) made by a set of mobile computing devices (-), from a first zone () to a second zone (), the method () comprising: obtaining () trajectory data representing a plurality of trajectories () collected from one or more mobile computing devices (-), at least some of the trajectories () passing through the first zone () and/or the second zone (); positioning () the trajectories () in a frame of reference defined relative to the map, wherein at least part of at least some of the trajectories () are positioned based on correspondence with other trajectories (); and processing the plurality of trajectories () positioned in the frame of reference defined relative to the map to determine the location and/or time.