A secondary radar comprising at least: - one secondary antenna made up of a set of columns of radiating elements each placed in a vertical plane, said antenna comprising a circuit for vertical microwave distribution, per column, of the signals received by the radiating elements of said column and a circuit for horizontal microwave distribution of the columns so as to form a sum channel (Σ) and an azimuth difference channel (Δ_AZI); - transmission means (3, 6) and means for generating polling signals, said signals being transmitted via said antenna to a target; - reception means (4, 6) and means for processing the signals received via said antenna in response to said polling signals, said processing means computing the location of said target by azimuth on the basis of the signals received by the sum and azimuth difference channels, with altitude information of said target being coded in the received signals, characterised in that, in order to provide additional altitude information without consuming system resources or losing performance, said radar further comprises a microwave distribution circuit combining: - the vertical microwave distribution of the signals coming from the radiating elements by weighted amplitude and phase adding so as to form an elevation difference signal (Δ_ELEV') per column; and - the horizontal microwave distribution of the elevation difference signals (Δ_ELEV') of the various columns received by their radiating elements by weighted amplitude and phase adding so as to form an elevation difference channel (Δ_ELEV) in the direction of the beam of said antenna; - the installation of said microwave distribution circuits (31, 41, 42, 43) on said antenna, a rotary joint RF wafer transmitting the signals from said elevation difference channel to reception circuits (32, 33, 4) dedicated to said channel; said processing means computing the altitude of said target on the basis of the comparison of the signals received by said sum channel (Σ) and by said elevation difference channel (Δ_ELEV) whilst considering the distance measured on said target. - one secondary antenna made up of a set of columns of radiating elements each placed in a vertical plane, said antenna comprising a circuit for vertical microwave distribution, per column, of the signals received by the radiating elements of said column and a circuit for horizontal microwave distribution of the columns so as to form a sum channel (Σ) and an azimuth difference channel (Δ_AZI); - transmission means (3, 6) and means for generating polling signals, said signals being transmitted via said antenna to a target; - reception means (4, 6) and means for processing the signals received via said antenna in response to said polling signals, said processing means computing the location of said target by azimuth on the basis of the signals received by the sum and azimuth difference channels, with altitude information of said target being coded in the received signals, - the vertical microwave distribution of the signals coming from the radiating elements by weighted amplitude and phase adding so as to form an elevation difference signal (Δ_ELEV') per column; and - the horizontal microwave distribution of the elevation difference signals (Δ_ELEV') of the various columns received by their radiating elements by weighted amplitude and phase adding so as to form an elevation difference channel (Δ_ELEV) in the direction of the beam of said antenna; - the installation of said microwave distribution circuits (31, 41, 42, 43) on said antenna, a rotary joint RF wafer transmitting the signals from said elevation difference channel to reception circuits (32, 33, 4) dedicated to said channel;