Detecting reflectors of an emitted electromagnetic pulse, using a received signal, by time-sampling the received signal and the emitted pulse at a same sampling frequency, each received sample corresponding to a return-trip distance for the emitted pulse between its transmitter and a possible reflector. The sampled received signal is divided by the emitted pulse sampled and temporally translated into an interval of duration equal to the emitted pulse divided into L samples, producing L results of the division. A weighted summing of the L results of the division is calculated, the sets of L weights each having a support on which the weights are not zero, every subinterval of length between L/n and L being the support for at least one set of weights and no support having a length of less than L/n, wherein the sums of the weights of a set all being equal, and n is a nonzero integer such that L/n is greater than or equal to 2. Finally, determining the minimum of the summations, wherein a nonzero minimum characterizes the amplitude of the pulse reflected by a reflector located at the distance corresponding to the start of a time interval being considered.