FOSREM’s FOS6 fiber-optic 6C rotational sensor.
Data recorded by Large Fiber-Optic Seismograph was presented in the 27th International Conference on Optical Fiber Sensors (OFS 2022) in Alexandria, Virginia, USA, 29 August – 2 September 2022.
The International Conference on Optical Fiber Sensors was established in 1983 and it is acknowledged as the world’s leading conference on all topics related to photonic sensing technologies. We presented two papers: “Large Fiber-Optic Seismograph detecting the rotation rate caused by natural factors as well as mining activities” as an oral presentation as well as “Towards uniformity of rotational events recording – common test engaging more than 40 sensors including a wide number of fiber-optic rotational seismometers” as a poster presentation. Presentations underlined the rapid development of rotational seismology. We provide appropriate systems for this field based on the optical fibre Sagnac interferometer. The data recorded by the system FOS5-04 confirms its capability to detect changes in Earth’s rotation rate associated with diurnal polar motion, as well as diurnal and semidiurnal tides.
To further expand the functionalities of the presented large fiber-optic seismograph, we plan to construct the next generation of FOS with three perpendicular axes. The ultimate goal is to achieve full six-degree-of-freedom ground-motion data.
see movie about experiment.
Geophysical Observatory Fürstenfeldbruck
Ludwigshöhe 8, D-82256 Fürstenfeldbruck
FOSREM team is doing a part of the active seismic experiment. All groups installed above 40 sensors and sensors matrix. FOSREM installed four fibre optics sensors – two FOS3 and two FOS5.
See our devices installed in the field.
IWGoRS 5th International Working Group on Rotational Seismology Sun Moon Lake, Taiwan 2019/09/22 – 26
The 5th IWGoRS workshop will be held at the Teacher’s Hostel, Sun Moon Lake, Taiwan, from September 22-26, 2019. Institute of Earth Sciences, Academia Sinica (IES) will be the local host. The workshop will cover on all aspects of rotational seismology including (but not limited to):
- instrumentation (portable sensors, ring lasers, tilt correction, etc)
- observation of rotations (application domains, best practices)
- array seismology (gradients, strains, rotations)
- data processing, wavefield interpolation, phase separation
- earthquake physics
- volcano seismology
- ocean-bottom observations
- earthquake engineering
- seismic inverse problems
With the advance of portable rotation sensor, we expect more rotation observations will be shown in the workshop.
The FOS-5 sensor contains a complete fibre-optic Sagnac interferometer with 250 mm diameter fiber-optics loop, analog to digital conversion circuits, FPGA based digital processing unit for close-loop operation, power conversion and management parts. All of these are placed in a robust case, meeting the IP67 requirements.
This internal digital processing unit provides rotation speed (Omega) value directly in digital form. The FOS-5 has an RS-485 interface for data and USB interface for diagnostic. The connection provides data transmission and power supply from PCU over only one, standard M12 cable within the distance of 500 meters.
On October, 17-18th 2014 Leszek Jaroszewicz, Anna Kurzych and Jerzy Kowalski participated in the Seventh European Workshop on the Seismic Behaviour of Irregular and Complex Structures (7EWICS) in Opole, Poland.
Since 1996, the European Workshop on the seismic behaviour of Irregular and Complex Structures (EWICS) has been taking place every three years under the auspices of Working Group (WG) 8 (Seismic Behaviour of Irregular and Complex Structures) of EAEE. The last Workshop, held in 2011 in Haifa, has about 40 papers included in the proceedings published by Springer. Its success confirms the interest of the scientific community in the covered topics.
Professor Leszek Jaroszewicz presented a paper “Fibre-Optic System for Rotational Events & Phenomena Monitoring: construction, investigation and area of application”. We also presented a poster and Fiber Optics Rotational Sensor in action. It was the debut FOSREM system in action.