A device for determining the location of a subject includes a positioning unit for generating each time period, t, position data corresponding to the location of the subject and motion data indicative of whether the subject is moving or stationary. There is a processor unit configured to, if the motion data indicates that the subject is moving at time period t, set the location of the subject at time period t to be the location corresponding to the position data. The processor unit is also configured to, if the motion data indicates that the subject is stationary at time period t, obtain from the positioning unit the position data for the next n time periods t determine the average position of the subject over the n time periods t and maintain as the location of the subject, the determined average position while the subject remains stationary.
