CABLE MOTION MONITORING

A method (900) of detecting motion of an electrical cable comprising at least one core comprises sending (S91) a time-domain reflectometry, TDR, signal from a point of measurement along each core of the cable. Reflections of the TDR signal from each core are received (S92) at the measurement point, and a reflectogram is generated (S93) for each core by correlating the TDR signal with the reflections. Each reflectogram is a waveform of relative impedance change against distance from the point of measurement. Motion of the cable is detected by comparing (S94) the reflectogram generated for each core with a reference reflectogram for the respective core, where each reference reflectogram was previously obtained when the cable was in a baseline position.