A method for characterizing a segment of a transmission line, a reference signal being injected into the line and a time-domain measurement of the reflection of the reference signal in the line being carried out, the method comprises the following steps: applying a deconvoluting step to the time-domain measurement so as to generate a deconvoluted temporal sequence comprising a plurality of amplitude peaks each corresponding to an impedance discontinuity; removing, from the amplitude of at least one obtained peak, the contribution of at least one secondary reflection of the signal from an impedance discontinuity; deducing, from the temporal position of each peak, a position of an associated impedance discontinuity in the line segment; and deducing, from the amplitude of each peak, an estimate of the real part of the reflection coefficient of a wave reflected from each identified impedance discontinuity.