We demonstrate a record length of distributed acoustic fiber sen sing (DAS) for pipeline monitoring. Both intrusion (third party interference) and leakage can be detected. An ultra-sensitive architecture enables record length (100km for a single ended fiber sensing system or 200 km for sensing from both ends) detection while advanced classification capabilities minimize both false and nuisance alarms. Targets are localized (high resolution of few meters) and classified.

While conventional DAS fiber sensing is limited to 20 -50km, increasing the effective range to 100 km can significantly decrease the number of systems and number of stations needed for long range pipeline monitoring.