A method for determining the three-dimensional alignment of components of a radar system is described. The radar system is provided that comprises at least one portion which is permeable by radar signals. The radar system is imaged by using millimeter waves emitted by an imaging system. In the image obtained, it is determined the highest magnitude reflection coinciding with at least one of an expected location and an expected distance of the surface of a first component of the radar system being of interest. At least one of the position and the distance of that surface is determined. From the measurement, the relative phase information received from each portion of that surface at the determined position and/or the determined distance is obtained. Processing the phase information obtained so as to obtain the azimuth and tilt of the surface. Further, a testing system is described.