Abstract: 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.

Abstract: Monitoring Electrical Systems with Multiple Ground Connection Points A method for monitoring an electrical system having multiple electrical ground connection points. The method comprises receiving reflectometry data that has been generated by performing time domain reflectometry on the electrical system, the time domain reflectometry being performed during a measurement time period. The method further comprises: determining a measured waveform from the reflectometry data, the measured waveform indicative of a measured state of the system during the measurement time period; obtaining a predetermined baseline waveform indicative of a baseline state of the system during a calibration time period; generating a difference waveform based on the measured waveform and the baseline waveform; and analysing the difference waveform to determine if there is a change of state in the electrical system between the calibration period and measurement period.