A radar for an autonomous guidance system for a platform , comprising a frame , a transmit-receive antenna for transmitting an electromagnetic wave transmitted in a pointing direction (P) and for receiving a received electromagnetic wave, and a pointing system for changing the orientation of the pointing direction (P) with respect to the frame , the pointing system comprising: - a primary pivoting device for pivoting the pointing direction (P) relative to the frame about a primary axis (R-R'), and - a secondary pivoting device for pivoting the pointing direction (P) relative to the frame about a secondary axis (S-S') orthogonal to the primary axis (R-R'), characterised in that the pointing system also comprises a tertiary pivoting device for pivoting the pointing direction (P) relative to the frame about a tertiary axis (G-G') orthogonal to the secondary axis (S-S'), and in that the antenna consists of an array antenna comprising an emission surface and a plurality of radiating elements distributed over the said emission surface , the radiating elements comprising a plurality of primary groups of radiating elements arranged successively with respect to one another along a primary direction (T-T') substantially orthogonal to the tertiary axis (G-G'), each primary group comprising at least one radiating element , the tertiary pivoting device consisting of a module for electronic scanning about the tertiary axis (G-G') adapted to phase-shift each wave generated by the or each radiating element of a primary group with respect to each wave generated by the or each radiating element of each other primary group , there being two primary groups , in which the primary pivoting device comprises an intermediate support on which the antenna is mounted, said intermediate support being mounted so as to be rotatable about the primary axis (R-R') relative to the frame . - a primary pivoting device for pivoting the pointing direction (P) relative to the frame about a primary axis (R-R'), and - a secondary pivoting device for pivoting the pointing direction (P) relative to the frame about a secondary axis (S-S') orthogonal to the primary axis (R-R'), characterised in that the pointing system also comprises a tertiary pivoting device for pivoting the pointing direction (P) relative to the frame about a tertiary axis (G-G') orthogonal to the secondary axis (S-S'), and in that the antenna consists of an array antenna comprising an emission surface and a plurality of radiating elements distributed over the said emission surface , the radiating elements comprising a plurality of primary groups of radiating elements arranged successively with respect to one another along a primary direction (T-T') substantially orthogonal to the tertiary axis (G-G'), each primary group comprising at least one radiating element , the tertiary pivoting device consisting of a module for electronic scanning about the tertiary axis (G-G') adapted to phase-shift each wave generated by the or each radiating element of a primary group with respect to each wave generated by the or each radiating element of each other primary group , there being two primary groups , in which the primary pivoting device comprises an intermediate support on which the antenna is mounted, said intermediate support being mounted so as to be rotatable about the primary axis (R-R') relative to the frame . <EOS>