1. An optical fiber infrasound sensor: A new lower limit on atmospheric pressure noise between 1 and 10 Hz.
- Author
-
Zumberge, Mark A., Berger, Jonathan, Hedlin, Michael A. H., Husmann, Eric, Nooner, Scott, Hilt, Richard, and Widmer-Schnidrig, Rudolf
- Subjects
DETECTORS ,NOISE ,SOUND ,OPTICAL fibers ,ACOUSTICAL engineering - Abstract
A new distributed sensor for detecting pressure variations caused by distant sources has been developed. The instrument reduces noise due to air turbulence in the infrasound band by averaging pressure along a line by means of monitoring strain in a long tubular diaphragm with an optical fiber interferometer. Above 1 Hz, the optical fiber infrasound sensor (OFIS) is less noisy than sensors relying on mechanical filters. Records collected from an 89-m-long OFIS indicate a new low noise limit in the band from 1 to 10 Hz. Because the OFIS integrates pressure variations at light-speed rather than the speed of sound, phase delays of the acoustical signals caused by the sensor are negligible. Very long fiber-optic sensors are feasible and hold the promise of better wind-noise reduction than can be achieved with acoustical-mechanical systems. [ABSTRACT FROM AUTHOR] more...
- Published
- 2003
- Full Text
- View/download PDF