Distributed acoustic sensing system

Distributed acoustic sensing system DAS product introduction
1
Distributed acoustic sensing technology:
Using the phase of coherent Rayleigh scattering light instead of light intensity to detect sound or vibration signals in the audio range can not only use the phase amplitude to provide the intensity information of sound or vibration events, but also use the linear quantitative measurement value to obtain the phase and frequency information of sound or vibration events

Das can be considered as a mobile interferometric acoustic sensor, which detects the external signal in the sensing fiber
When the sound or vibration causes the linear change of the phase of the interference light at the position, the quantitative measurement of the external physical quantity can be realized by extracting and demodulating the interference signal at different times of the position

2
Das measurement principle
Das measurement process: the laser emits light pulses along the optical fiber, and some light interferes with the incident light in the form of backscattering
After the interference light is reflected back, the backscattered interference light returns to the signal processing device, and the vibration acoustic signal along the optical fiber is brought to the signal processing device
Since the speed of light remains unchanged, the measurement results of acoustic vibration per meter of optical fiber can be obtained

3
Introduction to Das Technology
Maximum detectable 40KHz acoustic signal
It can detect the real-time acoustic signal around the optical fiber at any position (up to 40KHz)
Resistant to harsh environments such as high temperature and high pressure, and anti electromagnetic interference
Small size and strong networking ability
4
Basic performance index of DAS
Sensing distance: 0-50km
Spatial sampling resolution 1m
Frequency response range & lt; 40kHz
Noise level 10-3rad / & Radio; Hz
Real time data volume 100MB / S
Fast response time, typical 1 second
Fiber type ordinary single-mode fiber
Measurement channel 1, 2 and 4 (real-time performance is affected)
Data storage capacity 16TB solid state disk array