1. A method of eliminating spurious echoes in SAR imaging, comprising: defining SAR imaging parameters, calculating spectrum of signal received, in each distance bin, of a zone of interest, filtering spectra in each distance bin carried out by a bandpass filter centred on a central frequency of fixed echoes backscattered by a zone of interest, said central frequency being obtained by correlation of the measured spectrum with a theoretical shape of the spectrum obtained on the basis of characteristics of the radar antenna diagram, a step of SAR imagette formation, and a step of concatenating the SAR imagettes to form a final SAR image.