The paper presents the statistical analysis of trihedral corner reflectors RCS in presence of mass production and installation errors. It is shown that the degradation of RCS from its nominal value can be modeled by Beta distribution. The derived probability density functions (PDF) of corner reflector RCS is further exploited to design an optimal procedure for the radar power calibration technique, taking the aforementioned effect into account. This procedure can be used for real-time estimation of radar sensor healthiness parameter that characterises the sensing quality for awareness of human driver or automated driving system.