1CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS A low power and low noise infrasound sensor for temporary measurements Damien PONCEAU, CEA/DIF/DASE Sébastien PEYRAUD, CEA/DIF/DASE Patrick DUPONT, CEA/DIF/DASE Stéphane DENIS, CEA/DIF/DASE 2008 ITW, Bermuda, 03/11/2008

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW Presentation layout Temporary measurements : –Examples –Requirements IS Sensors and measuring chains : –State of the art –Comparison vs temporary measurement requirements MB2007 microbarometer : –Principle –Lumped elements model: acoustic impedance, response, noise and range –MB2007 calibration –Early field results

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW IMS network, DASE measurement sites For each site: –Volume:~ 30 L –Weight: ~ 20 kg –Power consumption:~ 7 W Dynamic range: > 108 dB Resistant equipment Pipes, meteo. and telecommunications not included IS stations installed by DASE

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW Some temporary measurements in IMS framework J. Guilbert, P. Harjadi, M. Purbawinata, S. Jammes, A. Le Pichon, B. Feignier, « Monitoring of Indonesian volcanoes with infrasound : preliminary results, », Infrasound Technology Workshop 2005, PAPEETE. J. Guilbert, P. Harjadi, M. Purbawinata, S. Jammes, A. Le Pichon, B. Feignier, « Monitoring of Indonesian volcanoes with infrasound : preliminary results, SURvey of Volcanic Arc of Indonesia », Infrasound Technology Workshop 2005, PAPEETE. A.Le Pichon, K. Antier, S. Vergniolle, M. Lardy, D. Drob, « Validating upper- wind models using infrasound from active volcanoes in Vanuatu », Infrasound Technology Workshop 2006, FAIRBANKS. A. Smirnov, V. Kunakov, A. Le Pichon, J. Guilbert, D. Ponceau « Preliminary results of localization and characterization of steady infrasound source as detected by I31KZ », Infrasound Technology Workshop 2007, TOKYO.

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW IMS IS Temporary measurements requirements Some IMS requirements 1 : –Able to solve IS Low Noise 1 Hz. –Dynamic range > 108 dB. Additional requirements 2 : –Portable, easy to transport and install. –Plug and play. –Resistant equipment –unsensitive to changes of geographical and meteorological conditions. 1 Working Group B, CTBTO Preparatory Commission, « Operational manual for infrasound monitoring and the international exchange of infrasound data », Rev. 10, 7 Sep O. Sow, CTBTO Preparatory Commission, « Terms of reference, procurement of infrasound experimental array », CTBTO Preparatory Commission Request for proposal, ref. no /SOW, 22 Aug 2007.

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW New “24 bits” acquisition systems Common features 1 : –Portable & plug and play: Power input range : ~ [9, 30] V Volume : < 5 L Weight : < 5 kg Power consumption : < 1.5 W –Dynamic range (with symmetric input) > 120 dB –Resistant equipment –And others 1 A. Brisbourne, A. Paul, M. Alvarez, R. Sleeman, « State of the art digitizers », ORFEUS NERIES joint workshop, October 2007.

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB 2005 : Current solution vs requirements –Portable & plug and play: Power input range: ~ [9; 30] V Volume & Weight: < 20 L, < 15 kg Power consumption: < 3 W (up to 2 W) –Dynamic range: > 108 dB (sensor) > 120 dB (digitizer) –Resistant equipment ~ 450 x 300 x 200 mm 3 Pipes, meteo. and telecommunications not included 2 days batteries included.

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 microbarometer : objectives A new Absolute pressure sensor : MB2007 Low power Integrated calibration Optimize the use of digitizer dynamic range Portable Reliable To better fit the low noise model at low frequencies

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 microbarometer: principle

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 microbarometer: acoustic impedance Modelled as a capacitance over infrasound frequency band Aneroid capsule impedance, Zaan Bellows and reference cavity spring rates are predominant over infrasound frequency band First batch of prototypes: Zedr >> Zece

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 microbarometer calibration, 10 Pa sinus A an, aneroid capsule effective area BL m, velocity transducer generator constant K an, aneroid capsule spring rate U o, output voltage p e, input pressure Considering previous simplifications: MB2007& IS Calibrator

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 microbarometer : calibration results

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 vs MB2005 comparison in LOR

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007: noise LOR Amplifier voltage noise Coil resistance thermal noise

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 pressure range Mechanics Digitizer

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW MB2007 specifications MB2005MB2007 Static Dynamic Range +/- 100 hPa+/- 250 hPa Weight5.5 kg< 2.5 kg Volume3 L< 1 L Power consumption3 Wpassive Relative CalibrationNOYES MB2007 & MB2005

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW Conclusion : near future measuring chain –Portable & plug and play: Power input range: ~ [9; 36] V Volume & Weight: 5 L, 9 kg Power consumption: < 800 mW (up to 300 mW) –Dynamic range: > 130 dB (sensor) > 120 dB (digitizer) –Resistant equipment

CEA/DIF/DASE / PONCEAU Damien, PEYRAUD Sébastien, DUPONT Patrick, Stéphane DENIS ITW Conclusions & Outlooks Temporary infrasound measurements imply new requirements for equipments. Thanks to recent developments in digitizers and infrasound sensors, more appropriate solutions become available. MB2007 outlooks: –Models and uncertainties on each parameters to improve –Susceptibility to harsh environments to study –Susceptibility to aging to study –To measure signals, collocated with other sensors