Distributed Acoustic Sensing (DAS); a Technology That Enables Continuous, Real-Time Measurements

Distributed acoustic sensing (DAS) is an advanced sensing technology that is used to measures the acoustic data in real-time along the entire length of a fiber optic cable. The optical fiber is the sensing element. These systems allow the detection of acoustic signals over large distances and in harsh environments. The sensing fiber is typically based on single-mode fibers although there are some specialized applications that use multimode sensing fibers. Distributed acoustic sensor works by injecting a pulse of laser light into the optical fibre.

Light travels down the fiber to intelligent distributed acoustic sensor where it is sampled. The time synchronization of the laser pulse allows the backscatter event to be accurately mapped to the fiber distance. The fiber acts as a sensor over its length and deliver real time information on physical surroundings and security. The optic fiber cable used in DAS can be loaded with many sensors. Distributed acoustic sensing offers an exceptional type of seismic measurement and can record dense seismic data for tens of kilometers.

Moreover, distributed acoustic sensing facilitates real-time monitoring of pipelines and wells to provide vital information in various challenging circumstances. DAS finds applications in monitoring of pipelines as well as highways, railroads, and borders. It is a recently developed technique which utilizes coherent optical time-domain reflectometry to accurately measure the phase and amplitude of vibrations along an optical fiber. DAS has enabled its implementation in other industry verticals as well, such as oil & gas, infrastructure, military, and transportation.

APAC is one of the fastest-growing markets for distributed acoustic sensing (DAS) solutions, with its increasing oil production and the development of military and infrastructure. In Union Budget 2021, the Indian Government has given a massive push to the infrastructure sector by allocating Rs. 233,083 crore (US$ 32.02 billion) to enhance the transport infrastructure.