Description
It has been shown that the coupling of the submarine cable to the ocean floor highly influence the recording of coherent and incoherent signals. Therefore, there is a need to characterize the cable coupling and identify the well coupled sections that can be used for coherent and incoherent signal analysis. This procedure will use two coupling indicators, the natural oceanic noise generated by the ocean-solid interactions and the signal-to-noise ratio from well recorded seismic events. Then, using these sections, a number of analysis and processing tools will be implemented, and its parameters adjusted to each purpose: waveform displays, real-time spectrograms, f-k diagrams, phase dispersion diagrams, PSD in space and time. Some of these tools can be implemented in-situ at the recording hardware and others can be applied after data transmission to the collecting centre. This task, using initial feedback from task 1, will focus in developing the real-time software that should allow for real-time or near real-time support to natural hazards and environment monitoring. The output of this task will contribute to task 5 where the 1-year recorded data will be investigated offline.
Expected results
Evaluate the coupling of the cable to the ground and ocean and define the cable sections to be used for preferential processing and analysis. Define the processing codes to decimate the large data of DAS in-situ, which provides over the Internet the relevant information required for real-time evaluation of natural hazards like earthquakes and tsunamis taking into consideration the added value allowed by the large spatial sampling of DAS. Define the processing codes to extract relevant information to be transmitted to the central collecting centre on the monitoring of the ocean, namely for sea state (wave height and period), surface currents, whale vocalizations, natural and anthropogenic sound scape; each of these applications with its own requirements. Define the processing tools to be run on real-time, deferred time, or on call, requesting from the DAS interrogator additional data.