Scientific instrument development
Scientific instrument development
Scientific instrumentations installed in Antarctic regions will face the most extreme climate on the planet, so it has to be tolerant of very low temperatures and robust enough to survive extreme wind speeds (e.g. Willis, 2008). On the basis of this, the scientific sensors have to be operative at very low temperature. Furthermore, one of the most challenging task is powering a remote system year round at polar latitudes because of following factors (e.g. Willis, 2008): i) solar radiation (insolation) varies through time from 24 hours of sun during the Antarctic summers to 0 during winters; ii) the high winds, common in polar regions, are often unpredictable in duration and in strength, which has led to severe problems using wind turbines as reliable power sources; iii) the cold temperatures of the polar night reduce the capacity of most batteries.
In the framework of the ICEVOLC project, a permanent seismo-acoustic station was developed able to face the aforementioned issues, hence allowing to record data for the entire Antarctic year (Contrafatto et al., 2018).
Sensors and DAS:
Sensors and digital acquisition system were chosen to be very robust, as well as operative at very low temperature:
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The digital acquisition system is a Guralp DM24S3EAM with stainless steel casing, minimum operating temperature equal to -40°C, storage capability equal to 32 Gb, 4 channels at 24 bit.
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The seismic sensor is a Guralp CMG 3T Polar, with stainless steel casing, minimum operating temperature equal to -55°C, and flat response from 120 sec to 100 Hz.
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The infrasonic microphone is a Chaparral 60Vx, rugged and field ready, minimum operating temperature equal to -40°C, and flat response from 0.03 Hz to 245 Hz.
Powering system:
The powering system is hybrid integrating solar panel, wind generator and batteries:
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The solar panel has a power of 140W and two glass plates to increase the resistance.
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The wind generator is a Le150w extreme with vertical axis, designed to survive 80mph winds and to provide up to 200 watt.
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The lead batteries are Haze HZY2-800 with capacity of 800 Ah, providing about 70% of the nominal capacity at - 25°C (560Ah).
© PNRA
© PNRA
Energy management:
The energy is managed by two controllers:
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FASEL controller: it was specifically designed for the ICEVOLC project, to carry out the following tasks: i) it measures the temperature inside the battery case; ii) it switches on and off the internal and external heaters; iii) it switches off the instruments (digital acquisition system, seismometer, infrasonic microphone) in case of low battery capacity to save the batteries.
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Morningstar TS45: it controls power generated by solar panel and wind generator to charge the batteries, and has a diversion charger system to manage the energy surplus.
Further details about the permanent seismo-acoustic station developed in the framework of ICE-VOLC project can be found in Contrafatto et al. (2018).
The following picture shows the permanent seismo-acoustic station installed on Mt. Rittmann (Antarctica):
References
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Contrafatto, D., Fasone, R., Ferro, A., Larocca, G., Laudani, G., Rapisarda, S., Scuderi, L., Zuccarello, L., Privitera, E., Cannata A. (2018). Design of a seismo-acoustic station for Antarctica. Review of Scientific Instruments 89, 044502, doi: 10.1063/1.5023481.
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Willis, Michael J., 2008. "Technologies to Operate Year-Round Remote Global Navigation Satellite System (GNSS) Stations in Extreme Environments", in Capra, A. and Dietrich, R. (Eds.) "Geodetic and Geophysical Observations in Antarctica: An Overview in the IPY Perspective", "Springer Berlin Heidelberg, DOI 10.1007/978-3-540-74882-3, p. 11-35.".