Waterfall Plots are three-dimensional visualizations that display a series of signal measurements, typically frequency or amplitude spectra, stacked sequentially along a time or position axis to reveal how signal characteristics evolve. In fiber-optic sensing research, waterfall plots are used to visualize distributed vibration data captured along a cable route, showing the location and timing of detected events simultaneously. They are a standard diagnostic and analysis tool in acoustic sensing, seismic monitoring, and optical network disturbance characterization.
We demonstrate a low-cost wavelength selectable distributed vibration sensor to monitor the whole routes in a 1×32 PON architecture with a unified sensitivity. The results obtained from the lab and a field testbed are presented.