Method and device for analyzing defects by means of reflectometry using a transfer function estimation

A method for analyzing faults by means of reflectometry in a network of transmission lines into which a first test signal is injected beforehand, the method comprising the steps of:

• measuring, with a measurement device, the first test signal after it has propagated through the network of lines,
• digitizing, with an analog-to-digital converter, the signal measured at a first sampling frequency,
• executing with a processor the steps of:
• sampling the first test signal at the first sampling frequency,
• converting the digitized measured signal and the sampled first test signal into the frequency domain,
• determining an estimate of a transfer function of the network by computing a ratio between said signals in the frequency domain,
• generating a second test signal having a second sampling frequency,
• determining frequencies which are present in the second test signal,
• interpolating the estimated transfer function for the frequencies which are present in the second test signal,
• converting the second test signal into the frequency domain,
• computing a product of the interpolated transfer function and of the second test signal in the frequency domain,
• determining an estimate of a measurement of the second test signal after it has propagated through the network of lines by converting a result of said product into a time domain, and
• detecting a fault in the network of transmission lines from the estimate of a measurement of the second test signal.