Transmission Line Fault Imaging Using Phaseless Inverse Scattering and Temporal Sparsity

A phaseless 1-D inverse scattering technique for detecting and imaging soft faults in lossy transmission lines is proposed. Its novelty is that it: 1) performs impedance profile imaging with only phaseless measurements and 2) integrates a temporal background subtraction sparsity technique to image temporal change across the impedance profile. The combination of these techniques removes the need for directional couplers and phase synchronization and reduces the required number of measurements. The novelty of the approach is that, even in its phaseless form, accurate linear expressions for the impedance profile are obtained, opening up significant flexibility in the techniques’ application. Numerical and experimental results show that the proposed techniques provide accurate results for a wide range of impedance profiles with limited phaseless measurements. The techniques have the potential for providing low complexity systems for accurately monitoring the formation of newly formed transmission line faults.