Examinando por Autor "Guerrero, H."

Mostrando 1 - 15 de 15

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A New Single-Sensor Magnetic Field Gradiometer
(Igneta Connect, 2009-08-13) Lucas, I.; Díaz Michelena, M.; De Manuel, V.; Plaza, J. A.; Duch, M.; Esteve, J.; Guerrero, H.
In this work a magnetic field gradiometer device has been developed. This device is not composed by two sensors separated a certain distance but by a single-sensor device which measures the real gradient value just at the point where it is wanted to be measured. The experimental set-up consists of a sensor head (a membrane with a fixed permanent magnet on it) vibrating at its resonance frequency, due to an alternating magnetic field gradient. Detection is performed using an optoelectronic method. Two different measurement techniques have been used: frequency measurements (the resonance frequency is measured for every external magnetic field gradient value) and amplitude measurements (the signal amplitude is measured without changing the resonance frequency obtained without an external magnetic field gradient applied). The mechanical stresses of the membrane are related with the dependence of both magnitudes (frequency and amplitude) on the external magnetic field gradient. The minimum and maximum value of the resonance frequency and signal amplitude respectively, correspond with magnetic forces equal to the magnet weight of the sensor head. This prototype shows a noise-limited sensitivity of 2 Gauss/m/√Hz at zero gradient. This device could be used also as a magnetic susceptometer.
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A Sol–Gel based magneto-optical device for the NANOSAT space mission
(Springer Link, 2009-03-31) Zayat, M.; Pardo, R.; Rosa, G.; Del Real, R. P.; Díaz Michelena, M.; Arruego, I.; Guerrero, H.; Levy, D.
On December 2004, the Spanish Space Agency INTA (Instituto Nacional de Técnica Aeroespacial) launched the first nanosatellite called NANOSAT (Fig. 1) on board an European rocket Ariane 5, from the French Guyana. The satellite consists of a hexagonal device of <19 kg of weight with a diameter of about 50 cm, which describes a LEO orbit of 655 km of altitude. The main objective of the satellite is to probe the operation and performance of micro- and nanotechnologies in space environment. One of the scientific experiments implemented on board was the Sol–Gel based magnetic nanosensor.
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A study of the optical properties of photopolymer Fabry-Perot microcavities by a dual-wavelength fibre optic architecture
(IOP Science Publishing, 2002-06-20) López Heredero, R.; Martín, S.; Fernández de Caleya, R. F.; Lobo Ribeiro, A. B.; Araújo, F. M.; Ferreira, L. A.; Santos, J. L.; Guerrero, H.; 0000-0002-7047-0273; 0000-0002-2988-1222; 0000-0003-2922-3489; 0000-0002-2197-8388; 0000-0002-0818-4268
We present a novel method to study the behaviour of the optical properties of photopolymer materials with temperature. The photopolymer is deposited on the tip of optical fibres by dip coating to fabricate low-finesse Fabry-Perot microcavities. The signal processing technique utilized to interrogate the cavity is based on the generation of two quadrature phase-shifted interferometric signals using two Bragg fibre gratings. This technique enables the determination of the values of the thermo-optical coefficient and the linear coefficient of thermal expansion of the photopolymer. The effectiveness of the processing technique is also exploited in the study of the dependence of the temperature sensitivity on the cavity thickness.
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Comparative performance of static-mode ferrous MEMS gradiometers fabricated by a three-step DRIE process
(IOP Science Publishing, 2010-05-21) Campanella, H.; Del Real, R. P.; Duch, M.; Guerrero, H.; Esteve, J.; Díaz Michelena, M.; Plaza, J. A.
Two MEMS structures—a cantilever beam and a quad-beam—have been designed and fabricated through a three-step deep reactive ion etching (DRIE) process. Devices feature target patterns to align with an external optical detection system and a micromachined cavity to embed an NdFeB hard mini-magnet, thus releasing the stress of structures. Structures are intended for magnetostatic gradient measurements. Induced magnetic fields generate an attracting force on the magnet that deflects the sensor. Deflection is optically detected through nanometer-resolution confocal microscopy. The static-mode sensitivity of up to 1.86 × 10−4 T m−1 demonstrates that MEMS gradiometers are able to perform in situ gradiometry with a single sensor and miniaturized size. Suitable techniques for integrated detection are discussed.
Acceso Abierto
COTS-Based Wireless Magnetic Sensor for Small Satellites
(Institute of Electrical and Electronics Engineers, 2010-05-06) Díaz Michelena, M.; Arruego, I.; Oter, J. M.; Guerrero, H.
We report on the utilization of a commercial off-the-shelf (COTS) magnetic sensor for the mission NANOSAT-01 and the set of tests that have been developed to up-screen it. The magnetic sensor head is a Wheatstone bridge formed by four anisotropic magnetoresistances (AMR). AMR sensors are an adequate choice for medium- to high-sensitivity (~3 mV/V/G) and resolution (~ 3 ¿G) requirements, mostly due to their low weight and volume that are so interesting for the aerospace industry. The whole system installed in NANOSAT-01 is formed by two biaxial sensors with two redundant PCBs (printed circuit boards) of RAD-HARD proximity electronics, which conditions the AMR output signal, measure the temperature, and resets the AMR. This magnetic sensor belongs to the attitude control system (ACS) of the satellite.
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Dosimeter for The Two Towers in SEOSAT-INGENIO Based on the TMP36 Temperature Sensor
(Institute of Electrical and Electronics Engineers, 2013-05-14) González Guerrero, M.; Jiménez, J. J.; Hernando, Carlos; Álvarez, Maite; Guerrero, H.; Instituto Nacional de Técnica Aeroespacial (INTA)
A dosimeter for space applications is presented. It is based on the ionization damage affecting the TMP36 sensors when they are exposed to external radiation, which produces an increase of their output voltages. This work explains the configuration, sensing mechanism and working modes of this device and reports the results obtained in a gamma radiation test carried out in March 2012. The test results allow us to select the mode of operation that provides the highest response to the TID, as well as the most sensitive devices. The highest sensitivity is above 100 μV/rad. This dosimeter is part of The Two Towers radiation monitor that will fly on board of the SEOSAT-INGENIO satellite.
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Focused-Ion-Beam-Assisted Magnet Fabrication and Manipulation for Magnetic Field Detection Applications
(ACS Publications, 2009-02-16) Campanella, H.; Del Real, R. P.; Díaz Michelena, M.; Duch, M.; Guerrero, H.; Esteve, J.; Plaza, J. A.
A focused-ion-beam-assisted technique intended for ultrasmall, hard-magnet fabrication has been developed. By means of ion-beam-induced milling and deposition, reduced-size NdFeB magnets were extracted from a macroscopic quarry and bonded to the surface of a thin-film bulk acoustic resonator (FBAR). Electrical characterization of the FBAR before and after bonding of the magnet was carried out, thus observing both a downshifting of the resonance frequency and a reduction of the quality factor of the resonator. The magnetic behavior of the nanomagnet has been confirmed by means of magnetometry measurements based on atomic force microscopy.
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In situ MEMS gradiometer with nanometer-resolution optical detection system
(Elsevier, 2010-04-05) Campanella, H.; Del Real, R. P.; Duch, M.; Serre, C.; Lucas, I.; De Manuel, V.; Guerrero, H.; Esteve, J.; Díaz Michelena, M.; Plaza, J. A.
Mechanically resonant ferromagnetic MEMS sensors intended for magnetic field gradient measurements are presented. Suspended quad-beams with proof mass have been designed to improve their sensitivity and to simplify the detection. Fabricated devices exhibit the compact size of current MEMS technologies and are built within a simple deep-reactive-ion etching-based process. Nanometer-resolution detection based on optical interferometry and signal processing techniques have been employed to find out dynamic-mode transformation factors of 6.25 × 10−3 T/m/Hz with 0.1-Hz resolution. The device performs in situ gradiometry with a single-sensor structure, which represents a technological advance to current-art gradiometers.
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In-orbit measurement of SET and DD fffects on optical wireless links for intra-satellite data transmission
(Institute of Electrical and Electronics Engineers, 2011-11-01) Arruego, I.; Martínez, J.; Guerrero, H.; Instituto Nacional de Técnica Aeroespacial (INTA)
In-orbit measurements of two experimental optical-wireless data links on board a polar LEO (Low Earth Orbit) spacecraft are presented. The effects of single event transients on the bit error rate, as well as those of displacement damage on the optoelectronic components being used, were measured. The results are consistent with those obtained from proton irradiations carried out in ground facilities.
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Magnetic Technologies for Space: COTS Sensors for Flight Applications and Magnetic Testing Facilities for Payloads
(Ingenta Connect, 2007-03-01) Díaz Michelena, M.; Del Real, R. P.; Guerrero, H.
The increasing trend of using Commercial of the Shelf components for Aerospace Applications makes Space Agencies open a brand new testing line devoted to the up-screening and characterization in extreme conditions of these "underqualified" components. The up-screening needs to deal with the tasks of degassing, temperature testing and thermal shock, vibration, ageing and stressing, and irradiation of the component under test. In this paper we report on the up-screening process, the previous magnetic characterization and the in-flight resulting data obtained with the magnetic sensors of NANOSAT-01 mission, one and a half years after the launch. The up-screening of the magnetic sensors used in this mission succeed. Their final in-flight qualification is on the road as the behavior of the sensors is nominal.
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Micromachined low-finesse Fabry-Perot interferometer for the measurement of DC and AC electrical currents
(Institute of Electrical and Electronics Engineers, 2003-04-22) López Heredero, R.; Santos, J. L.; Fernández de Caleya, R. F.; Guerrero, H.; López Heredero, R. [0000-0002-2197-8388]; Guerrero, H. [0000-0003-2922-3489]; Santos, J. L. [0000-0002-0818-4268]
A micromachined low finesse Fabry-Perot interferometer for measuring DC and AC electrical current is presented. Interrogation of the microcavity is achieved by a dual-wavelength fiber Bragg grating technique working in quadrature. A linear relation between the DC electrical current and the optical phase defined by the microcavity was detected. Large enhancement of the sensitivity of the microcavities is presented with the use of a planar coil instead of a power line. The sensitivity of the sensor with the planar coil configuration is 7.9 rad/A and resolution of ∼0.18 mA//spl radic/Hz is achieved when the distance between the planar coil and the transducer head is 2 mm. The response of the sensor for AC measurements is 0.14 V/A with a resolution of 6 mA//spl radic/Hz when the distance between the power line and the transducer head is 5.5 cm.
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Micromachined low-finesse Fabry-Perot interferometer for the measurement of low DC electrical currents
(Institute of Electrical and Electronics Engineers, 2002-05-10) López Heredero, R.; Santos, J. L.; Fernández de Caleya, R. F.; Araújo, F. M.; Ferreira, L. A.; Guerrero, H.; Guerrero, H. [0000-0003-2922-3489]; López Heredero, R. [0000-0002-2197-8388]
An optical fiber current sensor based on a permanent magnet fixed on the center of a micromachined Si membrane has been presented. The transducing operation principle is magneto-mechanical and has a linear response. A great improvement of the sensitivity of the microcavities was achieved by the use of a planar coil. Interrogation of the transducer has been carried out using a Fabry-Perot interferometer with an all-fiber detection system to avoid the influence of electromagnetic noise. The effectiveness of a fiber scheme based on the utilization of two fibre Bragg gratings to generate two quadrature phase-shifted interferometric signals has also been reported.
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Micromachined optical fiber current sensor
(OSA (The Optical Society) Publishing, 1999-09-01) López Heredero, R.; Fernández de Caleya, R. F.; Guerrero, H.; Los Santos, P.; Cruz Acero, M.; Esteve, J.; 0000-0002-2197-8388; 0000-0001-9440-7984; 0000-0003-2922-3489; 0000-0002-2131-1081
We describe a micromachined optical fiber current sensor. The sensing element consists of a squared silicon membrane (8 mm long and 20 µm thick) that has a cylindrical permanent magnet (NdFeB alloy, 3-mm diameter, 1.5 mm high) fixed on its central region. This structure allows the permanent magnet to vibrate in the presence of the magnetic field gradient generated by an ac. A linear relation between the electrical current and the magnet displacement was measured with white-light interferometry with an optical fiber low-finesse Fabry–Perot microcavity. A measurement range of 0–70 A and a minimum detectable intensity of 20 mA were obtained when distance D between the membrane and the electrical power line was 5 mm. The output signal directly shows a linear response with distance D.
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Optical wireless links for intra-satellite communications: reflection models and hardware optimization
(Aerospace Research Central, 2010-05-23) Tamayo, R.; Alonso, José; Jiménez, J. J.; Arruego, I.; Guerrero, H.; Instituto Nacional de Técnica Aeroespacial (INTA)
The present work is a study on the propagation channel (physical layer) for wireless infrared communications in intra-satellite environments. Substituting cables and connectors with optical links inside a spaceborn platform offers many advantages and represents some technical challenges. We show analytical calculations, simulations, and experimental results for reflection models for aerospace materials, as well as wavelength division multiple access techniques for channel multiplexing. Improvements in the selection and optimization of emitter-detector pairs are also presented.
Acceso Abierto
The MetNet vehicle: a lander to deploy environmental stations for local and global investigations of Mars
(European Geoscience Union (EGU), 2017-02-24) Harri, Ari-Matti; Pichkadze, K.; Zeleny, L.; Vázquez, L.; Schmidt, W.; Alexashkin, S.; Korablev, O.; Guerrero, H.; Heilimo, J.; Uspensky, M.; Finchenko, V.; Linkin, V.; Arruego, I.; Genzer, M.; Lipatov, A.; Polkko, J.; Paton, M.; Savijärvi, H.; Haukka, H.; Siili, T.; Khovanskov, V.; Ostesko, B.; Poroshin, A.; Díaz Michelena, M.; Siikonen, T.; Palin, M.; Vorontsov, V.; Polyakov, A.; Valero, F.; Kemppinen, O.; Leinonen, J.; Romero, P.; Finnish Meteorological Institute (Finland); Russian Space Research Institute; Instituto Nacional de Técnica Aeroespacial (INTA); Lavochkin Association (Russia); Harri, A. M. [0000-0001-8541-2802]; Schmidt, W. [0000-0002-8210-3868]; Korablev, O. [0000-0003-1115-0656]; Genzer, M. [0000-0002-3971-0152]; Haukka, H. [0000-0001-7653-5114]
nvestigations of global and related local phenomena on Mars such as atmospheric circulation patterns, boundary layer phenomena, water, dust and climatological cycles and investigations of the planetary interior would benefit from simultaneous, distributed in situ measurements. Practically, such an observation network would require low-mass landers, with a high packing density, so a large number of landers could be delivered to Mars with the minimum number of launchers. The Mars Network Lander (MetNet Lander; MNL), a small semi-hard lander/penetrator design with a payload mass fraction of approximately 17 %, has been developed, tested and prototyped. The MNL features an innovative Entry, Descent and Landing System (EDLS) that is based on inflatable structures. The EDLS is capable of decelerating the lander from interplanetary transfer trajectories down to a surface impact speed of 50–70 m s−1 with a deceleration of < 500 g for < 20 ms. The total mass of the prototype design is ≈ 24 kg, with ≈ 4 kg of mass available for the payload. The EDLS is designed to orient the penetrator for a vertical impact. As the payload bay will be embedded in the surface materials, the bay's temperature excursions will be much less than if it were fully exposed on the Martian surface, allowing a reduction in the amount of thermal insulation and savings on mass. The MNL is well suited for delivering meteorological and atmospheric instruments to the Martian surface. The payload concept also enables the use of other environmental instruments. The small size and low mass of a MNL makes it ideally suited for piggy-backing on larger spacecraft. MNLs are designed primarily for use as surface networks but could also be used as pathfinders for high-value landed missions.