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A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science
(Chemistry Europe: European Chemical Societies Publishing, 2019-08-02) Ruiz Bermejo, Marta; De la Fuente, J. L.; Carretero González, J.; García Fernández, L.; Rosa Aguilar, M.; Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
HCN polymers are a group of complex and heterogeneous substances that are widely known in the fields of astrobiology and prebiotic chemistry. In addition, they have recently received considerable attention as potential functional material coatings. However, the real nature and pathways of formation of HCN polymers remain open questions. It is well established that the tuning of macromolecular structures determines the properties and practical applications of a polymeric material. Herein, different synthetic conditions were explored for the production of HCN polymers from NHCN or diaminomaleonitrile in aqueous media with different concentrations of the starting reactants and several reaction times. By using a systematic methodology, both series of polymers were shown to exhibit similar, but not identical, spectroscopic and thermal fingerprints, which resulted in a clear differentiation of their morphological and electrochemical properties. New macrostructures are proposed for HCN polymers, and promising insights are discussed for prebiotic chemistry and materials science on the basis of the experimental results.
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A New Large-Scale Map of the Lunar Crustal Magnetic Field and Its Interpretation
(Advancing Earth and Space Science AGU, 2021-02-23) Hood, L. L.; Torres, C. B.; Wieczorek, Mark A.; Stewart, S. T.; Oliveira, Joana S.; National Aeronautics and Space Administration (NASA)
A new large-scale map of the lunar crustal magnetic field at 30 km altitude covering latitudes from 65°S to 65°N has been produced using high-quality vector magnetometer data from two complementary polar orbital missions, Lunar Prospector and SELENE (Kaguya). The map has characteristics similar to those of previous maps but better resolves the shapes and distribution of weaker anomalies. The strongest group of anomalies is located on the northwest side of the South Pole-Aitken basin approximately antipodal to the Imbrium basin. On the near side, both strong isolated anomalies and weaker elongated anomalies tend to lie along lines oriented radial to Imbrium. These include named anomalies such as Reiner Gamma, Hartwig, Descartes, Abel, and Airy. The statistical significance of this tendency for elongated anomalies is verified by Monte Carlo simulations. Great circle paths determined by end points of elongated anomaly groups and the locations of five individual strong anomalies converge within the inner rim of Imbrium and intersect within the Imbrium antipode zone. Statistically significant evidence for similar alignments northwest of the Orientale basin is also found. The observed distribution of anomalies on the near side and the location of the strongest anomaly group antipodal to Imbrium are consistent with the hypothesis that iron from the Imbrium impactor was mixed into ejecta that was inhomogeneously deposited downrange in groups aligned radial to the basin and concentrated antipodal to the basin.
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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.
Acceso Abierto
A novel induction-based device for the measurement of the complex magnetic susceptibility
(Elsevier, 2017-08-13) Díaz Michelena, M.; Mesa Uña, José Luis; Pérez jiménez, M.; Maicas Ramos, M. C.; Cobos Arribas, P.; Hernández Ros, C. A.; European Research Council (ERC)
A device named magnetic susceptometer for a complete determination of the magnetic complex susceptibility of materials and minerals has been conceived and manufactured as a complement for the in situ characterization of rocks during high resolution magnetic prospections. In this work a device and its capabilities for susceptibility measurements are described, the calibration performed with artificial samples, and the values of real and imaginary susceptibility of natural samples in a range comprising: χ = 10−4 to 10−7 [SI], representative of Earth and also Mars rocks.
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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.
Acceso Abierto
A Subcell Finite-Difference Time-Domain Implementation for Narrow Slots on Conductive Panels
(Multidisciplinary Digital Publishing Institute (MDPI), 2023-08-03) Ruiz Cabello Núñez, M. D.; Martín Valverde, A. J.; Plaza Gallardo, B.; Frövel, M.; Poyatos Martínez, D.; Rubio Bretones, Amelia C.; Gascón Bravo, Alberto; García, S. G.; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Ciencia e Innovación (MICINN)
Efficiently modeling thin features using the finite-difference time-domain (FDTD) method involves a considerable reduction in the spatial mesh size. However, in real-world scenarios, such reductions can lead to unaffordable memory and CPU requirements. In this manuscript, we present two stable and efficient techniques in FDTD to handle narrow apertures on conductive thin panels. One technique employs conformal methods, while the other utilizes subgridding methods. We validate their performance compared to the classical Gilbert-Holland model and present experimental results in reverberation environments to shed light on these models’ actual confidence margins in real electromagnetic compatibility (EMC) scenarios.
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Adsorption of water on porous Vycor glass studied by ellipsometry
(OSA (The Optical Society) Publishing, 2001-02-01) Álvarez Herrero, A.; López Heredero, R.; Bernabeu, E.; Levy, D.; 0000-0002-8462-0156; 0000-0002-2197-8388; 0000-0002-8957-5745; 0000-0001-9228-3412
The variation of the optical properties of porous Vycor glass (Corning, Model 7930) under different relative-humidity conditions was studied. The adsorption of water into the glass pores was investigated with spectroscopic ellipsometry. The change of the refractive index was Δn ∼ 0.04 between 5% and 90% relative humidity. A linear relation between the ellipsometer parameter tan Ψ, the amount of water adsorbed in the glass pores, and information about the pore-size distributions was established. The results are in accord with the values obtained from N2 isotherms, transmission electron microscope micrographs, and the manufacturer’s specifications (radius of ∼20 Å). The possibility of using this material as a transducer for implementation in a fiber-optic sensor to measure humidity was evaluated.
Acceso Abierto
Aerosol radiative impact during the summer 2019 heatwave produced partly by an inter-continental Saharan dust outbreak – Part 1: Short-wave dust direct radiative effect
(European Geoscience Union (EGU), 2021-04-30) Córdoba Jabonero, C.; Sicard, M.; López Cayuela, M. A.; Ansmann, A.; Comerón, A.; Zorzano, María Paz; Rodríguez Gómez, A.; Muñóz Porcar, C.; Ministerio de Ciencia e Innovación (MICINN); Agencia Estatal de Investigación (AEI); European Research Council (ERC); Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Economía y Competitividad (MINECO); Córdoba Jabonero, C. [0000-0003-4859-471X]; Sicard, M. [0000-0001-8287-9693]; López Cayuela, M. A. [0000-0002-8825-830X]; Comerón, A. [0000-0001-6886-3679]; Rodríguez Gómez, A. [0000-0002-9209-0685]; Unidad de Excelencia Científica María de Maeztu Grupo de investigación en Teledetección, Antenas, Microondas y Superconductividad UNIVERSITAT POLITECNICA DE CATALUNYA, MDM-2016-0600; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The short-wave (SW) direct radiative effect (DRE) during the summer 2019 heatwave produced partly by a moderate, long-lasting Saharan dust outbreak over Europe is analysed in this study. Two European sites (periods) are considered: Barcelona, Spain (23–30 June), and Leipzig, Germany (29 and 30 June), 1350 km apart from each other. Major data are obtained from AERONET and polarised Micro-Pulse Lidar (P-MPL) observations. Modelling is used to describe the different dust pathways, as observed at both sites. The coarse dust (Dc) and fine dust (Df) components (with total dust, DD = Dc + Df) are identified in the profiles of the total particle backscatter coefficient using the POLIPHON (POlarisation LIdar PHOtometer Networking) method in synergy with P-MPL measurements. This information is used to calculate the relative mass loading and the centre-of-mass height, as well as the contribution of each dust mode to the total dust DRE. Several aspects of the ageing of dust are put forward. The mean dust optical depth and its ratios are, respectively, 0.153 and 24 % in Barcelona and 0.039 and 38 % in Leipzig; this Df increase in Leipzig is attributed to a longer dust transport path in comparison to Barcelona. The dust produced a cooling effect on the surface with a mean daily DRE of −9.1 and −2.5 W m−2, respectively, in Barcelona and Leipzig, but the DRE ratio is larger for Leipzig (52 %) than for Barcelona (37 %). Cooling is also observed at the top of the atmosphere (TOA), although less intense than on the surface. However, the DRE ratio at the TOA is even higher (45 % and 60 %, respectively, in Barcelona and Leipzig) than on the surface. Despite the predominance of Dc particles under dusty conditions, the SW radiative impact of Df particles can be comparable to, even higher than, that induced by the Dc ones. In particular, the DRE ratio in Barcelona increases by +2.4 % d−1 (surface) and +2.9 % d−1 (TOA) during the dusty period. This study is completed by a second paper about the long-wave and net radiative effects. These results are especially relevant for the next ESA EarthCARE mission (planned in 2022) as it is devoted to aerosol–cloud–radiation interaction research.
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Anisotropic magnetoresistance (AMR) instrument to study the Martian magnetic environment from the surface: expected scientific return
(Springer Link, 2023-08-15) Díaz Michelena, M.; Fernández Romero, S.; Adeli, Solmaz; Henrich, Clara; Aspás, Alberto; Parrondo, M. C.; Rivero Rodríguez, Miguel Ángel; Oliveira, Joana S.; Instituto Nacional de Técnica Aeroespacial (INTA); Centros de Excelencia Severo Ochoa, BARCELONA SUPERCOMPUTING CENTER (BSC), SEV2015-0493
The ExoMars programme has the objective to answer to the question of whether life ever existed on Mars. The second mission comprising the Rosalind Franklin rover and Kazachok Surface Platform was designed to focus specifically on the characterization of the environmental parameters which can play an important role for the existence of life on the surface of the planet. One of these parameters is the magnetic field because of its ability of shielding the solar and cosmic radiation. For such characterization, the scientific suite of the Surface Platform counts with two instruments: the Anisotropic MagnetoResistance (AMR) and the MArtIan Ground ElectromagneTic (MAIGRET) instruments. The AMR goal is to characterize both the surface and subsurface and the time-varying magnetic fields, related to the crustal and the external fields respectively, at the ExoMars landing site in Oxia Planum. The operation to achieve these goals includes two phases, the first phase corresponding to the lander descent and the second phase in which the instrument is deployed on the surface. In this work, we simulate the first operations phase using synthetic magnetic field models, assuming that the different crustal units at the landing site might be magnetized. We also perform measurements in our laboratory to simulate the second phase operation of the instrument on the Martian surface. We discuss the capability of interpretation of the instrument, based on the available information of the landing site and the results from our models.
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Application of a Spherical Multi-Purpose Facility to the Selection of the Appropriate Radome for an On-Board POD Antenna
(Taylor and Francis Online, 2012-04-03) Poyatos Martínez, D.; Escot Bocanegra, D.; De Diego Custodio, E.; González Diego, I.; Sáez de Adana, F. M.; Montiel, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
This paper presents the application of a new multi-purpose facility for electromagnetic tests to the measurement of the influence of radomes on the radiation of an antenna. The antenna under test is part of a project for mounting a small, low-cost, low-power electronic system in the pod of an unmanned aerial vehicle. The shape of the radome is restricted to the pod physical specifications, but several materials could be tested to assess its effect on the antenna, and to select the best fitted for this particular application.
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Application of FDTD to HRRP Generation of a Cavity Model for NCTI Purposes
(Institute of Electrical and Electronics Engineers, 2011-07-04) Fernandez Recio, R.; Escot Bocanegra, D.; Poyatos Martínez, D.; Jurado Lucena, A.; Errasti Alcalá, B.; Montiel, I.; Instituto Nacional de Técnica Aeroespacial (INTA)
The application of a time-domain electromagnetic simulation code to a realistic and challenging problem like the high-resolution range profile (HRRP) generation of an inlet cavity model is presented in this paper. HRRPs can be used to accomplish noncooperative target identification (NCTI) of aircrafts by means of radar, and the database needed in this technique tends to be populated with predicted data obtained with software tools. Most codes employed with these purposes are frequency domain methods, which need multiple simulations at different adequately chosen frequencies, as well as some postprocessing, to get a radar signature. Instead, this paper focuses on finite difference time domain (FDTD) analysis of the response of a cavity, because of the relevance of these parts of an aircraft in the overall signature, and numerical results are compared with measurements performed by the authors in an anechoic chamber. This work also shows the advantages of using an electromagnetic code based on time domain for HRRP generation.
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Application of particle swarm optimization (PSO) to single-snapshot direction of arrival (DOA) estimation
(Institute of Electrical and Electronics Engineers, 2007-12-06) Escot Bocanegra, D.; Poyatos Martínez, D.; González, Iván; Sáez de Adana, F.; Cátedra, M. F.; Instituto Nacional de Técnica Aeroespacial (INTA)
This paper attempts to examine the feasibility of using an heuristic bio-inspired algorithm in DOA estimation. Specifically, particle swarm optimization (PSO) (Kennedy, et. al., 1995)
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Assessment of FEM simulations in EMC test setups for small aeronautical platforms
(Taylor and Francis Online, 2018-08-03) Plaza Gallardo, B.; Ramajo, O.; López, D.; Poyatos Martínez, D.; Escot Bocanegra, D.; Agencia Estatal de Investigación (AEI)
The rise of fly-by-wire systems together with the utilization of new composite materials make it more and more difficult to assess and guarantee aircraft electromagnetic compatibility (EMC). As a result, the design phase becomes of paramount importance in the aircraft production process. Performing actual EMC tests over different configurations in such a phase would be very costly and time consuming, so reliable computational techniques are being explored in the last years. However, proper validation is needed in order to gain confidence in the results obtained by simulations. In this regard, this paper presents the assessment of a simulation approach based on the finite element method to reproduce typical setups of an EMC test laboratory for small aeronautical platforms. The final test object is based on an unmanned aerial vehicle but, first, a simpler test case is used to tune and assess the simulation approach. Once the approach is both qualitatively and quantitatively validated with measurements, new setups involving the aeronautical specimen are analysed.
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Asymmetric Magnetic Anomalies Over Young Impact Craters on Mercury
(AGU, 2021-02-01) Galluzzi, V.; Wright, Jack; Rothery, D. A.; Hood, L. L.; Oliveira, Joana S.; National Aeronautics and Space Administration (NASA); Agenzia Spaziale Italiana (ASI); European Commission (EC)
Mercury's crustal magnetic field map includes anomalies that are related to impact craters. Mercury's surface has a low iron abundance, but it is likely that some impactors brought magnetic carriers able to register the planet's magnetic field that was present during impact. Anomalies associated with the relatively young Rustaveli and Stieglitz craters are asymmetric with respect to the crater center. We analyze the location of the magnetic anomalies and the impact crater morphologies to understand whether there is any correlation. We investigate the geological framework of these two craters to constrain the overall impact dynamics. In both cases, magnetic anomalies correlate well with the location of impact melt and the inferred impact direction. Both impact angles were probably 40°–45°, with preferential distribution of the melt downrange. Inversion dipoles suggest that the impact melt located downrange encompasses some magnetized material, which is hence likely responsible for the detected magnetic anomalies. We observe strong crustal magnetic field imprints near two recent craters on Mercury. We know that the crust of rocky planets may include magnetic elements like iron that can record the local magnetic field under certain circumstances. However, Mercury's crust is known to be remarkably poor in iron. In this study, we want to find out whether these observed magnetic imprints near craters happened by chance or if it can be explained by the impactors bringing iron to Mercury's surface. We make a joint-study of two different scientific areas: Geology and geophysics. Via the geological study, we found an uneven distribution of “impact melt,” which is material flung out of the crater in molten form during the impact that made the crater. Via the geophysical study, we found evidence that magnetized material correlates with the position of those pools that are found in the downrange direction of the impact. In conclusion, this study supports the hypothesis that iron was brought on Mercury by the impactors.
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Balance measurements on a frigate type ship model
(Elsevier LTD, 2020-10) Bardera, Rafael; García Magariño, A.; Instituto Nacional de Técnica Aeroespacial (INTA)
Balance measurements performed by testing sub-scaled ship models determine the global forces and moments acting on the ship, which allows knowing the power required for the ship's movement and provides insight to be applied in the design of the control systems used to steer the ship and to avoid instabilities while sailing. The ship superstructure may produce large separated regions and high air wake turbulence levels resulting in a set of fluctuations of the flow parameters usually determined by measuring velocity or pressure. This paper presents the balance measurement of the aerodynamic forces acting on the ship hull. Aerodynamic forces and moments produced on the ship can be interpreted as an integration of the flow parameters (velocity and pressure distributions) over the ship surface wetted by the air. Balance method provides averaged values and fluctuations of forces coefficients. Aerodynamic environment in the vicinity of a ship is influenced by a large number of factors (atmospheric wind, sea state, ship superstructure, masts, stacks, antennas …) affecting helicopter operations on board ships and their safety during the take-off and landing manoeuvres.
Acceso Abierto
BepiColombo Science Investigations During Cruise and Flybys at the Earth, Venus and Mercury
(Springer Link, 2021-02-11) Mangano, V.; Dósa, M.; Franz, M.; Milillo, A.; Joo Lee, Y.; McKenna Lawlor, S.; Grassi, D.; Heyner, D.; Kozyrev, A. S.; Peron, R.; Helbert, J.; Besse, S.; De la Fuente, S.; Montagnon, E.; Zender, J.; Volwerk, M.; Chaufray, J. Y.; Slavin, J. A.; Krüger, H.; Maturilli, A.; Cornet, T.; Iwai, K.; Miyoshi, Y.; Lucente, M.; Massetti, S.; Schmidt, C. A.; Dong, C.; Quarati, F.; Hirai, T.; Varsani, A.; Belyaev, D. A.; Zhong, J.; Kilpua, E. K. J.; Jackson, B. V.; Odstrcil, D.; Plaschke, F.; Vainio, R.; Jarvinen, R.; Ivanovsky, S. L.; Madár, A.; Erdos, G.; Plainaki, C.; Plainaki, C.; Alberti, T.; Alberti, T.; Aizawa, S.; Benkhoff, J.; Murakami, G.; Quemerais, E.; Hiesinger, H.; Mitrofanov, I. G.; Iess, L.; Santoli, F.; Orsini, S.; Lichtenegger, H.; Laky, G.; Barabash, S.; Moissl, R.; Huovelin, J.; Kasaba, Y.; Saito, Y.; Kobayashi, H.; Baumjohann, W.; Oliveira, Joana S.; European Research Council (ERC); National Aeronautics and Space Administration (NASA); Mangano, V. [0000-0002-9903-4053]
The dual spacecraft mission BepiColombo is the first joint mission between the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) to explore the planet Mercury. BepiColombo was launched from Kourou (French Guiana) on October 20th, 2018, in its packed configuration including two spacecraft, a transfer module, and a sunshield. BepiColombo cruise trajectory is a long journey into the inner heliosphere, and it includes one flyby of the Earth (in April 2020), two of Venus (in October 2020 and August 2021), and six of Mercury (starting from 2021), before orbit insertion in December 2025. A big part of the mission instruments will be fully operational during the mission cruise phase, allowing unprecedented investigation of the different environments that will encounter during the 7-years long cruise. The present paper reviews all the planetary flybys and some interesting cruise configurations. Additional scientific research that will emerge in the coming years is also discussed, including the instruments that can contribute.
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BIANCHA: A spherical indoor facility for bistatic electromagnetic tests
(Institute of Electrical and Electronics Engineers, 2017-01-05) López Rodríguez, P.; Hernán Vega, O.; Poyatos Martínez, D.; Escot Bocanegra, D.; Ministerio de Economía y Competitividad (MINECO)
BIANCHA (BIstatic ANechoic CHAmber) is a singular facility located at the premises of the National Institute for Aerospace Technology (INTA), Spain. It was devised to enable both monostatic and bistatic automatic positioning and, therefore, permits to perform a wide variety of electromagnetic tests. In this regard, it is worth noting that in the last years, a renewed interest has arisen in bistatic radar. Some of the main reasons behind this renaissance are the recent advances in passive radar systems added to the advantages that bistatic radar can offer to detect stealth platforms. On the other hand, with the aim of developing new aeronautic materials with desired specifications, research on the electromagnetic properties of materials has also attracted much attention, demanding engineers and scientists to assess how these materials behave in the presence of electromagnetic fields. Consequently, this paper introduces BIANCHA and demonstrates its applicability for these purposes by presenting results of tests for two different applications: a bistatic scattering analysis of scaled aircraft targets and the extraction of the electromagnetic properties of composite materials utilized in an actual aeronautical platform.
Acceso Abierto
Calibration of QM-MOURA three-axis magnetometer and gradiometer
(European Geoscience Union (EGU), 2015-01-30) Díaz Michelena, M.; Sanz, R.; Cerdán, M. F.; Fernández, A. B.; Ministerio de Economía y Competitividad (MINECO)
MOURA instrument is a three-axis magnetometer and gradiometer designed and developed for Mars MetNet Precursor mission. The initial scientific goal of the instrument is to measure the local magnetic field in the surroundings of the lander i.e. to characterize the magnetic environment generated by the remanent magnetization of the crust and the superimposed daily variations of the field produced either by the solar wind incidence or by the thermomagnetic variations. Therefore, the qualification model (QM) will be tested in representative scenarios like magnetic surveys on terrestrial analogues of Mars and monitoring solar events, with the aim to achieve some experience prior to the arrival to Mars. In this work, we present a practical first approach for calibration of the instrument in the laboratory; a finer correction after the comparison of MOURA data with those of a reference magnetometer located in San Pablo de los Montes (SPT) INTERMAGNET Observatory; and a comparative recording of a geomagnetic storm as a demonstration of the compliance of the instrument capabilities with the scientific objectives.
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Calibration OGSEs for multichannel radiometers for Mars atmosphere studies
(Springer Link, 2018-02-01) Jiménez Martín, Juan José; Álvarez, F. J.; González Guerrero, M.; Martín, I.; Fernán, A. A.; Arruego, I.; Apéstigue, Víctor; Fernández Marín, Juan Manuel; Instituto Nacional de Técnica Aeroespacial (INTA); Ministerio de Economía y Competitividad (MINECO)
This work describes several Optical Ground Support Equipment (OGSEs) developed by INTA (Spanish Institute of Aerospace Technology—Instituto Nacional de Técnica Aeroespacial) for the calibration and characterization of their self-manufactured multichannel radiometers (solar irradiance sensors—SIS) developed for working on the surface of Mars and studying the atmosphere of that planet. Nowadays, INTA is developing two SIS for the ESA ExoMars 2020 and for the JPL/NASA Mars 2020 missions. These calibration OGSEs have been improved since the first model in 2011 developed for Mars MetNet Precursor mission. This work describes the currently used OGSE. Calibration tests provide an objective evidence of the SIS performance, allowing the conversion of the electrical sensor output into accurate physical measurements (irradiance) with uncertainty bounds. Calibration results of the SIS on board of the Dust characterisation, Risk assessment, and Environment Analyzer on the Martian Surface (DREAMS) on board the ExoMars 2016 Schiaparelli module (EDM—entry and descent module) are also presented, as well as their error propagation. Theoretical precision and accuracy of the instrument are determined by these results. Two types of OGSE are used as a function of the pursued aim: calibration OGSEs and Optical Fast Verification (OFV) GSE. Calibration OGSEs consist of three setups which characterize with the highest possible accuracy, the responsivity, the angular response and the thermal behavior; OFV OGSE verify that the performance of the sensor is close to nominal after every environmental and qualification test. Results show that the accuracy of the calibrated sensors is a function of the accuracy of the optical detectors and of the light conditions. For normal direct incidence and diffuse light, the accuracy is in the same order of uncertainty as that of the reference cell used for fixing the irradiance, which is about 1%.

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