Quasi-distributed sensing using enhanced sensing structures

A system for distributed acoustic sensing, comprising:

• a distributed acoustic sensing (DAS) station to launch a DAS signal into a DAS fiber within an optical cable;
• an enhanced sensing array, the enhanced sensing array comprising a plurality of sensing components formed in select ones of a plurality of cable joints along the optical cable, arranged over a plurality of spans, wherein a given sensing component of the plurality of sensing components comprises:
• a DAS fiber coil, forming a portion of the DAS fiber;
• and
• a low elastic modulus outer shell, surrounding the DAS fiber coil.

A method for distributed acoustic sensing comprising:

• launching an outbound distributed acoustic sensing (DAS) signal from a DAS station into a DAS fiber;
• conducting the outbound DAS signal through a sensing array that includes a plurality of sensing components arranged in a plurality of cable joints, each sensing component formed of a low elastic modulus material and including a local DAS fiber coil that forms a portion of the DAS fiber wherein the sensing component is one of a plurality of sensing components, arranged in a plurality of cable joints, respectively in a plurality of spans of a multi-span communications system;
• and
• measuring a power, phase, frequency, or polarization of a reflected signal based upon the outbound DAS signal after the outbound DAS signal traverses the DAS fiber coil.