Common Anomalous Signals in Distributed Acoustic Sensing (DAS) Systems and Their Handling

No light is entering the fiber optic cable

There is a reflection peak at the start of the signal, but no signal follows; this indicates that light is not entering the fiber.

This issue typically originates from the DAS host; the fiber optic connector is not properly connected, preventing light from entering the fiber. Possible causes include:

1. Mismatched fiber optic connectors.
2. Contamination on the fiber end face; the end face needs to be cleaned.
3. The FC/APC slot is not properly aligned.

There are continuous areas of weak signal in the central region

In the optical power curve shown in the figure above, we can see two distinct, continuous regions with low-amplitude dips. This type of signal is typically caused by line attenuation and requires attention to the optical fiber link.

Normal light intensity signal

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