Sensnet Analytics AS, created at the Norwegian University of Science and Technology (NTNU), is developing distributed acoustic sensing (DAS) systems that transform ordinary fiber-optic cables into networks of sensors. The use of fiber technology is rapidly evolving, and at NORSAR, we leverage our extensive expertise in vibration. The OptoDAS interrogator is using a unique interrogation technique providing low-noise and long-range quantitative phase measurements in single mode optical fibers. The conventional technique for measuring the reflected DAS signal from the fiber is pulsed interrogation where short pulses are. DAS technology, ideal for long-distance monitoring of infrastructure like powerlines and underwater cables, ensures grid reliability through real-time monitoring, fault detection, and security surveillance. Fiber cables along railways enable DAS technology, monitoring trains for safety, security. If a section of the optical fibre is subjected to strain, the propagating light will experience an optical phase delay. By analyzing the back-reflected signal one can extract the optical phase modulations induced along the optical fibre.
[PDF Version]