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.
The 4th IWGoRS workshop were held at the Evangelische Akademie Tutzing (near Munich, Germany), June 20-23, 2016. The workshop was focus on any aspect of rotational ground motion including the recording of rotations, instrumentation, earthquake sources, non-standard rheologies, inverse problems, geodesy, earthquake engineering, long-period seismology, array-derived rotation, noise-correlation studies, ring laser technology, Earth’s rotation, problems of fundamental physics and others.
Our team has prepared one oral presentation and two-day demonstration of mobile Fosrem System in action. The presentation given by Prof. Leszek R. Jaroszewicz is avaiable here. Also Fosrem System data sheet is avaiable for download.
Our team announces that new mobile FOG sensor FOS2/3 is ready for operation. We have done several tests, simulating different types of earthquakes and standard waves.
It’s a mobile, fiber-optic system, based on Sagnac interferometer for monitoring rotational events and phenomena. The sensor device is optimized for measurement of the rotational rate with sensitivity equal to 2*10E-8 rad/s/Hz in pass band from DC to 327,68 Hz. The above mentioned sensitivity as well as rotation rate dynamic range up to 10 rad/s covers weak as well as strong rotational motions connected with irregular object movements, occurring during strong winds, tectonic moves and earthquakes. In this way, the developed system is dedicated to monitoring the rotational vibration in such objects as wind power plants, tall irregular buildings, bridges, and unstable grounds as well as rotational events connected with earthquakes.
The data sheet is avaiable here.
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.
The FOSREM team of scientists (Jaroszewicz L, Krajewski Z, Kowalski J.) participated in the 3rd International Workshop on Rotational Seismology (3IWGoRS) in Christchurch, New Zealand. This workshop was organized by the University of Canterbury in Christchurch.
Professor Leszek Jaroszewicz showed a presentation on “Fiber Optics System for Rotational Events&Phenomena Monitoring”. Zbigniew Krajewski and Jerzy Kowalski showed an infographic of the technical implementations of FOSREM rotational sensors.
The start of FOSREM project began in Agust 2011. The Military University od Technology and m-Soft Sp. z o. o. signed an consortium agreement. The goal of the consortium is to develop a supersensitive rotational motion sensors.
We outline the development and the application in a field test of the Autonomous Fibre-Optic Rotational Seismograph (AFORS), which utilizes the Sagnac effect for a direct measurement of the seismic-origin rotations of the ground. The main advantage of AFORS is its complete insensitivity to linear motions, as well as a direct measurement of rotational components emitted during seismic events.