Point capteur de rotation R1

Point capteur de rotation R1

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DUT

2X EENTEC R1 derived from automotive industrie

2X EENTEC R1 derived from automotive industrie

SpecificationsSpecifications

Our goal : add new studies to our mid-band sensor i.e. 30s-1sOur goal : add new studies to our mid-band sensor i.e. 30s-1s

Operating principle: Electrochemical motion transducerResolution @ 1 Hz 1.2xE-7 rad/secDynamic Range 110 dBSelf Noise Level < 1 microradian/sec RMSSensitivity 50V/rad/secFrequency 0.05 to 20 Hz ±3 dBOutput Signal Swing ±5V Clip Level @ 1 Hz 01.0 rad/secTranslational Sensitivity NoneParasitic Resonances None

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Preliminary studies

• Rotational Data From the Taiwan Earthquake (ppt)This presentation prepared by Prof Liu, Academia Sinica and others detail the analysis of rotational seismic data obtained from the R-1 rotational seismometer and broadband seismometers from the September 26th, 2005 Taiwan Earthquake.

• Tilts in Strong Ground Motion This is paper published by Vladimer Graizer discusses how tilting of the strong motion Accelographs base can severely impact its response to ground motion.

• Effects of Tilt on Strong Motion Data Processing This paper published by Vladimer Grazer discusses ignoring tilt sesnitvity may produce unreliable results, especially in calculations of permanent displacement and long-period calculations.

• Laboratory and Field Testing of Two Rotational Seismometers (UCLA and USGS)

Only strong motion studies / High Freq i.e. > 1Hz

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Largentiere earthquake M=4.5

EENTEC R1 + CMG3-90s EENTEC R1 + CMG3-90s

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Largentiere earthquake M=4.5

Timing resultTiming result

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Largentiere earthquake M=4.5

Timing result filter 6th order High pass 1HzTiming result filter 6th order High pass 1Hz

Small signal !!!

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Largentiere earthquake M=4.5

Spectro + psdSpectro + psd

poor dynamic

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Vanuatu 09/03/2011 M=7

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Vanuatu 09/03/2011 M=7

Timing result filter 6th order High pass 0.01Hz Low pass 0.1HzTiming result filter 6th order High pass 0.01Hz Low pass 0.1Hz

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Need amplification ! To reach Low frequency ?

Non inverting gain x 1000 AD8671

• Bandwidth = 9.34 kHz

• Low input bias 12 nA

• Noise figure 3.6 nV/sqrt(Hz) including resistors

Non inverting gain x 1000 AD8671

• Bandwidth = 9.34 kHz

• Low input bias 12 nA

• Noise figure 3.6 nV/sqrt(Hz) including resistors

• @ 1Hz noise level = 500nV => Rsb = 200

• @ 0.1Hz noise level = 10uV => Rsb = 10

• Pour le CMG3 Rsb@1Hz = 400000

• L22 Rsb@1Hz = 40000

• @ 1Hz noise level = 500nV => Rsb = 200

• @ 0.1Hz noise level = 10uV => Rsb = 10

• Pour le CMG3 Rsb@1Hz = 400000

• L22 Rsb@1Hz = 40000

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Guerrero M=6

• Nothing happened…• Nothing happened…

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Conclusion

• Useful for building structure, tremor studies (GGAP ?) or strong motion in addition to an adequate amplification

• Useful for building structure, tremor studies (GGAP ?) or strong motion in addition to an adequate amplification

• FOG aircraft system MEMS ? Or equivalent for low frequency…

• FOG aircraft system MEMS ? Or equivalent for low frequency…