Persistent Scatterer Interferometry To Detect Railway Track Anomalies Using Terrasar-X Observations

Abstract

This study investigates the potential of space-borne Synthetic Aperture Radar Interferometry for efficient detection of track anomalies using the Swiss Federal Railways (SBB) railway network as an example. The condition of the ballast substructure is crucial for track service life, and moisture accumulation is a primary cause of deterioration and can manifest itself by subsidence. Current operational methods for track condition assessment have limitations, and remote sensing techniques offer a promising alternative. Using a time-series of TerraSAR-X observations, we performed a persistent scatterer interferometry (PSI) analysis to estimate surface deformations and further analysed the deformation rates and variability along a 22km track section in Switzerland. The study explores the hypothesis that the variability of PSI-derived deformation estimates along the railway track can be related to longitudinal height measurements from track geometry vehicles. When compared with chord-based measurements from SBB, our preliminary results showed a promising correlation, suggesting that the variability in deformation measurements can indeed be linked to longitudinal height measurements obtained from track geometry vehicles. If proven effective, a satellite-based evaluation method could significantly reduce resources required for railway infrastructure maintenance.