Related Experiment Video
Updated: Jun 6, 2025
10:52
Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior
Published on: April 13, 2016
8.7K
Multi-point vibration positioning method for long-distance forward transmission distributed vibration sensing
Optics Express
|November 22, 2024
Summary
This study demonstrates using telecom fiber optic cables for undersea monitoring. The new method precisely locates multiple simultaneous vibrations, enhancing geological and maritime surveillance capabilities.
Area of Science:
- Geophysics and Oceanography
- Optical Sensing and Communications
Background:
- Submarine fiber optic cables offer a unique opportunity for monitoring undersea events like earthquakes and tsunamis.
- Existing sensing methods face limitations in spatial resolution and distinguishing multiple simultaneous events.
Purpose of the Study:
- To develop and validate a distributed sensing system for long-distance vibration detection using existing submarine fiber optic cables.
- To enhance the capability of distinguishing and quantifying multiple simultaneous vibration events.
- To overcome the spatial resolution limitations imposed by traditional time-domain sampling rates.
Main Methods:
- Comparative analysis of external physical perturbations on submarine optical cables and unprotected optical fibers.
- Implementation of intensity and phase demodulation-based sensing systems for vibration sensing.
- Extension of the phase-spectrum time delay method for forward-transmission distributed sensing.
- Experimental demonstration over a 202.3 km single-span sensing distance.
Main Results:
- Successful multi-vibration positioning with an accuracy as low as 17.9 m for sine-wave vibrations.
- Achieved a spatial resolution of 1.25 m, surpassing previous fundamental limits.
- Demonstrated phase sensitivity of 40.6 mrad/µε and intensity sensitivity of 7.1%/µε.
- Tested frequency range of 0.01-100 Hz with real-time processing capabilities.
Conclusions:
- The forward transmission approach can transform the global internet fiber-optic network into a large-scale ocean observation network.
- This technology allows for enhanced undersea event monitoring without compromising existing telecommunication operations or bandwidth.
- The developed system offers significant potential for real-time, high-resolution monitoring of the marine environment.
Related Concept Videos
01:21Distributed Loads: Problem Solving
624
Beams are structural elements commonly employed in engineering applications requiring different load-carrying capacities. The first step in analyzing a beam under a distributed load is to simplify the problem by dividing the load into smaller regions, which allows one to consider each region separately and calculate the magnitude of the equivalent resultant load acting on each portion of the beam. The magnitude of the equivalent resultant load for each region can be determined by calculating...
624
01:30Electronic Distance Measuring Instruments
27
Electronic Distance Measuring Instruments (EDMs) are essential tools in modern surveying, offering precise distance measurements by emitting electromagnetic signals and calculating the time required for these signals to travel to a target and return. Two primary types of signals are used in EDMs — light waves and microwaves — each suited to specific environmental and distance requirements. Light-wave-based EDMs utilize either infrared or laser light, providing high accuracy over short...
27
01:19Distributed Loads
511
Distributed loads are a common type of load that engineers and scientists encounter in various practical situations. Distributed loads often refer to a type of load spread over a surface or a structure and can be modeled as continuous force per unit area.
For example, consider a bookshelf filled with books stacked vertically adjacent to each other. The weight of the books is evenly distributed over the length of the shelf. As a result, the pressure at different locations on the surface of the...
For example, consider a bookshelf filled with books stacked vertically adjacent to each other. The weight of the books is evenly distributed over the length of the shelf. As a result, the pressure at different locations on the surface of the...
511
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
915
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
915
01:15Discrete Fourier Transform
219
The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present...
219
01:29Relative Motion Analysis using Rotating Axes-Problem Solving
389
Consider a crane whose telescopic boom rotates with an angular velocity of 0.04 rad/s and angular acceleration of 0.02 rad/s2. Along with the rotation, the boom also extends linearly with a uniform speed of 5 m/s. The extension of the boom is measured at point D, which is measured with respect to the fixed point C on the other end of the boom. For the given instant, the distance between points C and D is 60 meters.
Here, in order to determine the magnitude of velocity and acceleration for point...
Here, in order to determine the magnitude of velocity and acceleration for point...
389