Scientists are looking for new ways of employment for distributed acoustic sensors (DAS). The fiber optic system contains a mandrel with a wounded with sensitized optical fiber. It is the acoustic sensor for a heterodyne that is protected for underwater use.
Nowadays, the DAS system can be used both for military purposes as well as for peaceful life. In the military, they are mostly utilized for submarine locations. While they are also in active use for monitoring sea animals’ life or finding and exploring marine mineral sources. The fiber optic systems based on the DAS technology have more advantages over the other items. First of all, they are thin and reliable. Secondly, there are no underwater electrical devices. And finally, the systems with acoustic sensors are immune to electromagnetic interference.
These devices usually contain an array of DAS sensors along with the fiber. Herewith, the arrays are up to a hundred or even fewer acoustic sensors because of the technical restrictions. The spacing between these acoustic sensors is fixed. That’s why there are some limitations in marine acoustic detection, for example.
The recent researches from China exploited a distributed acoustic sensing based on heterodyne coherent detection and demonstrated its field-testing. The optical cable contains a supporting mandrel, special optical fiber, and cable sheath. Acoustic signals from the fiber optic system disturb the mandrel and the fiber. That all causes phase changes which are the desired signal. The whole model was created to analyze the equivalence and specific character of the acoustic wave response.
With the array signal processing, the DAS device can easily find underwater acoustic signal sources and track motion trajectories. Moreover, the results of the experiments are highly accurate.
There are also obvious benefits of distributed acoustic sensors (DAS) in various industries. Most of which are elements of longer-term goals.
Some of the potential advantages of a distributed acoustic sensing are numbered below:
- a low-cost acquisition system;
- a simple design;
- no electrical energy required in the fiber optic cable;
- the fiber optic cable is suitable for harsh environments (dust, temperature, harmful gases);
- the fiber optic cable is immune to the radiations such as EMI (Electromagnetic Induction) & ESD (Electrostatic Discharge);
- the fiber optic system can transform several kilometers long sensor that enables it to monitor on a truly distributed basis.
According to the researchers, the production of fiber optic systems based on the DAS technology can be easily automated. However, there is still a space for developing and finding new ways of optimization.
Optromix is a DAS system manufacturer that provides top of the line distributed acoustic sensing systems suitable for monitoring commerce networks. If you have any questions or would like to buy a DAS system, please contact us at info@optromix.com