The invention relates to a cross antenna comprising linear sub-antennas and to the associated processing. More specifically, the invention relates to an antenna (1) comprising: first (2) and second (3) linear sub-antennas which are equipped with sensors (21-2M, 31-3N) forming first and second line segments and generating a basic signal (Si', Gj'), the angle between the respective directional vectors of the first and second tangents to the midpoint respectively of the first and second line segments being between 30.degree. and 150.degree.; an antenna processing device (4, 5) forming combined signals (VSi, VGj); a signal-processing device (6, 7) generating combined useful signals (TSi, TGj); a device (8) for calculating the correlation coefficients ([Cij]) between the combined useful signals; and a device (8) for generating a detection signal ([Rij]) when a correlation coefficient exceeds a threshold. The invention can be used, for example, to obtain an antenna having fewer sensors for an equivalent performance level.