the design and manufacture of high-tech equipment devoted to: • Navigation, • Positioning, • Underwater imaging. iXblue at a glance 600+ employees 80% export 100+ M€ turnover An international high technology company
through vertical integration • iXblue has end-to-end control of its value chain, from the design work carried out in its engineering offices through manufacturing in the company's own production shops. • This organization gives the group great flexibility, allowing it to adapt better to the specific needs of its customers and also to market trends. Its control over the performance of its products and its capacity to adapt are guarantees of quality and excellence. 6 centers of excellence in France St Germain en Laye headquarters Besançon La Ciotat Bonneuil Brest Lannion
at the heart of iXblue's inertial navigation systems, the Fiber-Optic Gyroscope is the ultimate precision rotation sensor, using the path of photons through an optical fiber as its sensing element. • By using massless particles for the measurement, Fiber-Optic Gyroscope is entirely insensitive to linear accelerations and no cross coupling can happen. • The FOG is the result of more than 30 years of research and development and is today considered to be the best gyroscope in the world: its performance is deemed genuinely unlimited.
series of scientific breakthroughs, iXblue has forged a unique identity to become a group with global reach and multiple areas of innovative know-how. • From design to manufacturing, iXblue is structured around 6 centers of excellence, located in France. • Our key assets issues are: • Mastery of cutting edge technology • Close and long-term relationships with our customers • Committed and agile teams Tested with in-house motion simulator Accelerometers Optical fiber Integrated optical circuit
Photonics Inertial solutions Underwater acoustics Ship building Mechatronics Survey operations Underpinned by its unique technologies, iXblue offers customers turnkey solutions to help them conduct their sea, land and space operations more efficiently.
The unique technologies developed by iXblue have found a variety of fields of application, continuously opening up new opportunities for innovation. • iXblue technology is at work everywhere from the ocean depths - 11,000 meters under the sea to outer space - some 1.5 million kilometers above the Earth. Energy & Marine Construction Research Labs Naval & Land Defence Commercial shipping Aerospace Fishing blueSeis rotational seismology solutions Geosciences
comme « preuve » ! (en fait la théorie de la relativité bien appliquée aboutit au même résultat) • Effet basé sur le retard créé par rotation entre deux ondes lumineuses contra-propagatives au sein interféromètre en anneau. SOURCE OPTIQUE PHOTODETECTEUR COUPLEUR 2X2 COI BOBINE A B Une onde part de A, parcourt 5000m, et arrive à B Une onde part de B, parcourt 5000m, et arrive à A
Avec : ω pulsation de λ longueur L longueur fibre D diamètre moyen A aire N nombre de spires S surface totale = A x N Df =ωDt = ω. . W = 2pc l . .. W = 2p l . ..p. W = 2p l . W Retard Sagnac Déphasage 2 cos ) cos 1 ( 2 2 0 0 f f P P P = = Intensité optique
Modification du facteur d’échelle Réponse de l’interféromètre Baisse de puissance moyenne de la source Fonction de transfert du modulateur • Facteur d’echelle (P0) • Dynamique réduite • Non-linéarité => BOUCLE FERME Réponse modulée, et linéarisée Une mesure optimisée
so crucial? The state-of-the-art sensitivity of the general rotation sensor is not yet enough for a useful geophysical application. With its brand new range of products blueSeis, iXblue opens up a broad field of possibilities for seismology, continuously pushing back the boundaries. [...] note the utility of measuring rotation near a rupturing fault plane [...] but as of this writing seismology still awaits a suitable instrument for making such measurements. Aki and Richards, Quantitative Seismology (1980) (2002)
so crucial? time a earthquake happens, the ground rotates. Any motion has 6 degrees of freedom: • Linear translation (3 DoF) • Angular rotation (3 DoF) Did you know that blueSeis now offers the possibility to measure complete ground motion.
so crucial? The capacity to distinguish rotations from translations is key to seismology measurement. But today, standard seismometers usually mix them up and characterize precisely the type of wave that is measured. • P-Wave • S-Wave • Love Wave • Rayleigh Wave Translation only Rotation & Translation Rotation & Translation Rotation & Translation * In isotropic media only
Bernauer, M., A. Fichtner, and H. Igel (2012), Measurements of translation, rotation and strain: New approaches to seismic processing and inversion, J. Seismol., 16(4), 669-681, doi:10.1007/s10950-012-9298-3. Bernauer, M., A. Fichtner, and H. Igel (2009), Inferring Earth structure from combined measurements of rotational and translational ground motions, Geophysics, 74(6), WCD41-WCD47, doi:10.1190/1.3211110. 2. Improving the recovery of earthquake source characteristics (point and finite source inversion) Bernauer, M.; Fichtner, A. & Igel, H. (2014), Reducing non-uniqueness in finite source inversion using rotational ground motions, Journal of Geophysical Research: Solid Earth, 119(6), 4860-4875, doi: 10.1002/2014JB011042. Donner, S., Bernauer, M., Igel, H., Inversion for seismic moment tensors combining translational and rotational ground motions, Geophys. J. Int., 207: 562-570, doi: 10.1093/gji/ggw298. Reinwald, M., Bernauer, M., Igel, H., and Donner, S., Improved finite-source inversion through joint measurements of rotational and translational ground motions: A theoretical study, Solid Earth, doi: 10.5194/se-2016-67. blueSeis, a revolution for rotational seismology 6 Good reasons:
van Driel, M.; Wassermann, J.; Pelties, C.; Schiemenz, A. & Igel, H. (2014), Tilt Effects on Moment Tensor Inversion in the Nearfield of Active Volcanoes , Geophysical Journal International, 202(3):1711-1721, doi:10.1093/gji/ggv209. Lindner, F., J. Wassermann, M. Schmidt-Aursch, K.U. Schreiber and H. Igel, Sea-floor ground rotation observations: potential for improving signal-to-noise ratio on horizontal OBS components, SRL, doi: 10.1785/0220160051. Pillet, R., Deschamps, A., Legrand, D., Virieux, J., Béthoux, N., & Yates, B. (2009). Interpretation of broadband ocean-bottom seismometer horizontal data seismic background noise. Bulletin of the Seismological Society of America, 99(2B), 1333-1342. Boroschek, R. L., & Legrand, D. (2006). Tilt motion effects on the double-time integration of linear accelerometers: an experimental approach. Bulletin of the Seismological Society of America, 96(6), 2072-2089. 4. Array type processing with a point measurement (with 6C observations) Wassermann, J., Wieteck, A., Hadziioannou, C.,and Igel, H., Towards a Single Station Approach for Microzonation: Using Vertical Rotation Rate to Estimate Love-Wave Dispersion Curves and Direction Finding, Bull. Seis. Soc. Amer., 106(3):1216-1330, doi: 10.1785/0120150250. blueSeis, a revolution for rotational seismology 6 Good reasons:
J. Wassermann, M. Käser, J. de la Puente, and U. Schreiber (2009), Observations and modelling of rotational signals in the P-Coda: constraints on crustal scattering, BSSA, 99(2B), 1315-1332, doi:10.1785/0120080101. 6. Seismic Wavefield reconstruction A theorem says that if one measures wavefield gradients (e.g. rotations) then the seismic wavefield can be reconstructed with half the number of stations along one dimension. In a 2D array this would be a 4-fold reduction in the number of sensors. E.g., Robertsson, J. O. A., Moore, I., Vassallo, M., Özdemir, A. K., van Manen, D. J., and Özbek, A., 2008, On the use of multicomponent streamer recordings for reconstruction of pressure wavefields in the crossline direction: Geophysics, 73, A45-A49. Vassallo, M., Özbek, A., Özdemir, K., van Manen, and Eggenberger, K., 2010, Crossline wavefield reconstruction from multi-sensor streamer data: Part : Geophysics, 75, WB53-WB67 & WB69-WB85 blueSeis, a revolution for rotational seismology Why is rotational seismology so crucial?
• blueSeis is an active member of the ROMY project, granted by the European Research Council, and leads by LMU and TUM teams from Munchen. • More publications and quotes about ROMY are available on Research Gate. Eric Hand - "Lord of the rings" Science 21 Apr 2017 Vol. 356, Issue 6335, pp. 236-238 Schreiber et al. - Integration and initial operation of the multi-component large ring laser structure ROMY (EGU 2017-5628) Bernauer et al. - BlueSeis3A - full characterization of a 3C broadband rotational ground motion sensor for seismology (EGU 2017-15512) Joshi et al. - The case for 6-component ground motion observations in planetary seismology (EGU 2017-3840) Sebe et al. - Measurement of the rotational motion induced by the Amatrice earthquake, with iXblue portable sensor at LSBB (EGU 2017-15447) Chow et al. - The development of a rotational magnitude scale (EGU 2017-4064) Donner et al. - Inversion for seismic moment tensors from 6-component waveform data (EGU 2017-3509) Gebauer et al. - Design and construction of a large 4C ring laser: ROMY (EGU2 017-10170) • For more information about blueSeis and ROMY, please go to: • www.blueseis.com • http://romy-erc.eu/
blueSeis-Survey Portable 3-component rotational seismometer Performances Broadband (0.01 to 100 Hz) Low noise (< 20 nrad/s/ Hz) High dynamic range Plug & Play Easy to deploy No calibration needed Maintenance free Embedded digitizer GNSS time stamping Web interface Benefits No linear sensitivity No cross coupling North finding function Laboratory 1-component rotational seismometer Still in development! blueSeis-1X is a seismometer dedicated to seismologic stations. It is composed of a large FOG for extremely precise rotational measurement. Performances Broadband (0.01 to 100 Hz) Extremely low noise (~ 2 nrad/s/ ) High dynamic range Benefits Compared to giant-RLG, blueSeis-1X is an industrial field-proven product, with a particularly attractive price/performance ratio. High precision seismographic survey To ensure a high level of performance of your motion simulator or scientific instrument, it is essential to check that the ground on which it is installed is more stable than the system itself. For that purpose, iXblue can provide you with a high precision seismographic survey to measure the rotational stability of the ground up to 2 ArcSec and 2.10-5 deg/sec @ 1Hz.
1st mockup: Improved optical design 2nd mockup: large mechanical design 3rd mockup: large mechanical design and longer coil Final mockup: improved optical design on large scale radius / side 5 cm 9 cm 22,7 cm 22,7 cm 50 cm Length 1 km 5 km 0,8 km 5,0 km 7 km Area for 1 turn 0,008 m² 0,025 m² 0,16 m² 0,16 m² 0,79 m² nb of turns 2 500 8 840 560 3500 1 592 Total area 20 m² 225 m² 91 m² 570 m² 1250 m² Theoretical limit ARW = rad*noise limit 100 nrad/s/ 10 nrad/s/ 22 nrad/s/ 3,5 nrad/s/ 1.5 nrad/s/ Experimental ARW 260 nrad/s/ 11 nrad/s/ 43 nrad/s/ 9 nrad/s/ 2 nrad/s/ ratio exp/theo 2,6 1,1 2,0 2,6 1,3 Presented at navigation product Karlsruhe ISS 2016 EGU 2017 Karlsruhe ISS 2017 AGU 2017
• 1200 x 1200 x 300 mm • 60 kg • ~2 nrad/s/VHz • From 100Hz to > 100seconds • Scale factor stability better than 1000ppm for life • Same electrical I/O than blueSeis-3A/3B ~100k€ pour 1C // 250k€ pour 3C @ ~5nrad/s/VHz ~150k€ pou 1C // 375k€ pour 3C @ ~2nrad/s/VHz
fully strap-down fiber-optic gyrocompass (FOG) and attitude reference system, is therefore a prerequisite for: • Trustworthy 6-axis seismology measurements • Extremely precise analysis of polarization of seismic waves • Reliable signal-to-noise ratio for array derivated rotation measurement Quadrans Features Complete gyrocompass Unique strap-down FOG Small & Compact Plug & Play Ethernet, Web-based MMI Benefits Fast-setting time No maintenance Easy integration High reliability Dockable on top of blueSeis-3A To guarantee high precision and reliability of seismologists measures, it is crucial to make sure that rotation and translation seismometers are perfectly aligned.
• Capacity to distinguish P-Waves from S-Waves • Capacity to measure rotations locally, at all wavelenghts • Possibility to obtain the direction of the epicentre blueSeis-3A • blueSeis-3A is a key instrument of measurement of near-field earthquakes.
Demonstration of blueSeis- to volcanology Aim: Demonstrate the importance of blueSeis' rotational measurements. The induced rotations are strong because of the swelling of the volcano before the eruption, which makes a rotational measurement at one point necessary. Context: Three systems were installed on the flanks of the volcano in order to better understand the volcano's internal mechanisms. Stromboli, Sicily September, 2016
Demonstration of blueSeis-3A' near-field measurement capabilities Aim: Demonstrate the strong relevance to near-field seismology. Thanks to blueSeis, many earthquakes, including those with very low magnitudes, could be measured locally at one point. The usual techniques of rotational measurement by network are constrained to assume a uniform rotation, obviously false when it is close to the source. Context: A system was installed at the heart of the Italian seismic crisis. Norcia, Italy December, 2016
estimate rotational motions, scientists have been using so far their translation sensor arrays, but they obtain a local measure of subsurface velocity. • This limit leads to: • Incapacity to detect ground heterogeneity • Necessity of seismometer arrays • Higher seismometer density • More logistics (installation time, etc.) • With blueSeis-3A, these limits now belong to the past. • The product makes it possible to measure phase velocity locally (at one point) right under the system, without having to build hypotheses. • With GNSS time stamping, digitizer embedded and Ethernet connectivity, blueSeis-3A fits perfectly within any linear arrays. • Its web interface and true heading function guarantee reduced deployment time and decreased cost of installation.
the usefulness of rotational measurement for ground tomography Aim: Quantify the improvement in resolution that rotational information provides in the context of ground tomography. With blueSeis, a network of 25 sensors would suffice (compared to the 100 sensors currently required). Context: In partnership with the universities of Munich and ETH-Zurich as well as the Swiss manufacturer Nagra, an active source soil seismology study was carried out by the blueSeis system to prepare for the installation of a nuclear site. Zurich, Switzerland January, 2017
At the bottom of the ocean, the rotational movements of the sea can perturbate or even dominate seismic measurements. Lindner, F., J. Wassermann, M. Schmidt-Aursch, K.U. Schreiber and H. Igel, Sea-floor ground rotation observations: potential for improving signal-to-noise ratio on horizontal OBS components SRL • blueSeis-3A, in its underwater version, offers the ability to measure the absolute value of the rotational movements of water and denoise scientific instruments. • By using light (photons) for the measurement, Fiber-Optic Gyroscope is - unlike any other technologies on the market - entirely insensitive to linear accelerations and no cross coupling can happen.
physicists improve the data given by their scientific instruments and obtain the absolute value of their measure, blueSeis offers 3 solutions enabling to actively compensate the movements observed. • blueSeis-3A is a portable, broadband, low-noise rotational seismometer able to characterize and monitor structural or seismic rotations in order to compensate them. • blueSeis-1X is a laboratory, broadband, extremely low-noise rotational seismometer that can measure and monitor with absolute precision, structural, seismic and microseismic rotations, in order to compensate them. • blueSeis-Survey is there to help scientists find the best place for their large instruments. The system can characterize with high precision the rotational stability of the ground (up to 2 ArcSec and 2.10-5 deg/sec @ 1Hz) and observe deformations over very long periods of time, ranging from one hour to a month.
buildings Aim: Understand the building's resonant modes in order to characterize the materials of which it is constructed and participate in its conservation. Context: Two systems were installed in the Giotto Campanile of Florence Cathedral. Florence, Italy October, 2016
of blueSeis- -field measurement capabilities, compared with array derivation Aim: Demonstrate that blueSeis- seismic measurements are equivalent to that of the expanded seismometer network. Context: 600 meters underground, measurement of the Italian earthquakes, in cooperation with the French Alternative Energies and Atomic Energy Commission (CEA) and LSBB. LSBB of Rustrel (Low-Noise Underground Laboratory) July, 2016
of blueSeis- -field measurement capabilities, compared with Giant-RLG Aim: Characterize the blueSeis sensors and their teleseismic measurement capability at a range of about 1,000 km Context: Two Italian earthquakes were measured by blueSeis at the observatory in Fürstenfeldbruck. blueSeis similar to the signal obtained from the giant laser gyro, an item of laboratory equipment that costs more than three million euros. Fürstenfeldbruck , Germany November, 2016