Methods and devices for determining axis of symmetry of self-driving vehicle (SDV) and for calibrating a Light Detection and Ranging (LIDAR) system are disclosed. One of the axes of the system of coordinates of the LIDAR system extends along a normal direction of a ground surface. the method includes acquiring a subset of detected points in the system of coordinates; generating a subset of mirror-image points based on the subset of detected points; projecting the subset of mirror-image points onto the subset of detected points so as to define pairs of overlapping data points; using symmetrically opposite detected points for determining the axis of symmetry of the SDV in the system of coordinates of the LIDAR system; and calibrating the LIDAR system using an angular offset between the axis of symmetry of the SDV and an other one of the axes of the system of coordinates of the LIDAR system.