Abstract: An augmented reality method for monitoring an event in space includes acquisition of a plurality of images of space having at least two landmarks by a camera of a portable device. Space being associated with a three-dimensional reference frame and the portable device being associated with a two-dimensional reference frame. A three-dimensional position and orientation of the space in relation to the camera is determined. The instantaneous position, within the reference frame of the space, of a mobile element moving in the space is received. The position of the mobile element in the two-dimensional reference frame is calculated from transformation parameters calculated from the three-dimensional position and orientation of the space in relation to the camera. An overlay at a predetermined distance in relation to the position of the mobile element in the two-dimensional reference frame is displayed on the screen. Also, a portable electronic device implements the method.