We demonstrated a record length of distributed acoustic fiber sensing (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 fiber sensing system or 200km for dual system) detection while advanced classification capabilities is minimising both false and nuisance alarms. Targets are localised (high resolution of few meters) and classified (into target's type and activity type).

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