1. A method of geofencing, comprising: a Kalman filter module to filter individual location fixes retrieved for a target device; determining an estimated position of said target device; determining an estimated heading and velocity of said target device; establishing a quality estimation from location data retrieved for said target device; detecting a geofence boundary crossing using said estimated position of said target device; and establishing a trip profile model for said target device based on historical velocity and heading information relating to said target device.