An iterative method for detecting is provided, with at least one receiver satellite in orbit, a target possessing reflective properties that are different from those of the area in which the target is found, by GNSS reflectometry, wherein the reflected GNSS signals are received by an active antenna of the receiver satellite comprising a plurality of antenna elements, the method comprising a step of determining assumed positions of the target, for which positions it is desired to detect the target, and, forming beams and tracking GNSS signals in accordance with these assumptions.