The radar comprises in known manner a transmitter (1), a transmitting antenna (E.sub.1), two receiving antennas (R.sub.1,R.sub.2), mixers (6,7) and means for processing the subtractive beat signals supplied by the mixers for effecting detection of the bearing of a target (10) and of the range and/or the relative velocity of the target. According to the invention, a target simulator is provided to correct the phase errors of electrical and mechanical origins. The simulator comprises a transmission circuit including a modulator (11) and a simulated target echo transmission antenna (E.sub.2) which transmits towards the receiving antenna. The radar also includes means for processing a beat signal derived from the simulated echo and for effecting detection of the simulated target bearing and means for correcting phase errors.