Mean azimuthal profile of the correlation pattern (left) and typical correlation map to illustrate the S/N measurement (right), the same configuration as in Fig. 1. The pixels used to evaluate the noise as the standard deviation of the distribution are shown in blue. The pixels that are considered for the signal of the planet, as defined in Sect. 3.3, are shown in red. Top: simulation with a low noise level (example with a star at 1.8′′ from the planet). Bottom: simulation with a higher noise level (example with a star at 0.6′′ from the planet).