Jammer location is based on detected powers received by at least one receiver of signals from the satellite navigation system on board a carrier, by estimation, for each satellite, of the power of the noise at the output of each receiver according to the bearing and distance with respect to the carrier, a calculation of the sum of estimated powers, and extraction of the local maxima in terms of bearing and distance by using a synthetic aperture antenna carrying out a coherent integration of received signals in the direction of each bearing angle by using the known movement of the carrier, in which estimation of the power of the noise at the output of each receiver uses a plurality of coherent integrators and non-coherent integrators, with durations matched to the transit time of a source in the beam of the antenna for various distances for the non-coherent integrators.