1. A system for determining an orientation of at least one first wheel of a vehicle, comprising: at least one first target configured to be integrally coupled to said first wheel; image capturing means configured so as to acquire a first two-dimensional image of said first target; and a processing device, operatively coupled to said image capturing means and configured to process said first two-dimensional image, wherein said first target comprises a plurality of target elements having a three-dimensional shape, reciprocally arranged according to a pre-determined three-dimensional geometric configuration, wherein said three-dimensional geometric configuration is designed to define a set of three orthogonal target vectors (vx trg , vy trg , vz trg ) defining a target reference system (SdR trg ), the spatial orientation of which corresponds to the orientation of said wheel; said processing device being configured to process said first two-dimensional image according to said three-dimensional geometric configuration, to identify therein positions of said target elements and projection vectors (vx trg _ prj , vy trg _ prj , VZ trg _ prj ) of said target vectors (vx trg , vy trg , vz trg ), and to determine a spatial arrangement of said target vectors (vx trg , vy trg , vz trg ) with respect to a reference system based on geometrical characteristics of said projection vectors, thereby determining orientation characteristics of said first wheel; wherein said processing device is configured to determine linear measurements of said projection vectors (vx trg _ prj , vy trg _ prj , vz trg _ prj ) in said first two-dimensional image, and to determine spatial rotation angles of said set of three orthogonal target vectors (vx trg , vy trg , vz trg ) with respect to said reference system as a function of said linear measurements and of corresponding actual known measurements of said target vectors (vx trg , vy trg , vy trg ).