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| Titel |
A Novel UAS Rapid Deployment Platform for Targeted Gas Sampling and Meteorological Soundings at Altitudes up to 2,700 masl |
| VerfasserIn |
Rick M. Thomas, Colin Greatwood, Tom Richardson, Jim Freer, Rob MacKenzie, Rebecca Brownlow, David Lowry, Rebecca E. Fisher, James France, Euan G. Nisbet |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250107119
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| Publikation (Nr.) |
 EGU/EGU2015-6811.pdf |
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| Zusammenfassung |
| This research project has developed Unmanned Aerial System (UAS) technologies for
intelligent targeting and collection of atmospheric gas samples to investigate the so-called
Southern Tropical Methane Anomaly, for which it is necessary to sample air below and above
the trade-wind inversion. Air parcels above and below the South Atlantic trade-wind
inversion can have markedly different trajectories and, hence, encounter very different
methane source regions. The system is intelligent in that high resolution temperature and
humidity sensors linked to the ground station characterise the atmospheric profile on the
upward flight to ensure the platform targets the appropriate sample elevations on the
downward trajectory. This capability has been proven to an altitude of 2,700 metres above sea
level (masl; ca. 700Âmb) at Ascension Island in the South Atlantic and shown that
rapid and repeat deployment and sample collection is achievable. Three novel eight
motor multirotor UAS (or octocopter) platforms were developed at Bristol Robotics
Laboratory (BRL) using primarily off –the-shelf components with a custom-built
main fuselage. Gas sampling and atmospheric sensor systems were designed by
the University of Birmingham. Our paper explores the capability of this UAS and
provides some initial results from the air sampling campaign conducted in September
2014.
Thirty-eight sampling flights were conducted over 12 days and the resulting 47 samples
analysed for their CH4 concentration using the high-precision Picarro Cavity Ring Down
Spectrometer already installed at Ascension Island. A subset of samples were sent for
δ13CCH4 analysis in Egham, UK. The flights were conducted up to an altitude of 2,700m
with 2,000m being typical. There were no major incidents although variable zero and high
wind situations above the trade wind inversion (typically at 1,800m) both presented unique
challenges and required careful flight planning strategies and in flight trajectory changes. As a
result algorithms were developed to estimate in-flight wind speed and direction from aircraft
attitude data.
The results from the meteorological samples compared favourably with modelled data
from the local Met Office station and we also show comparisons with wind speed
and direction as well as insights gained from the CH4 analysis. Finally, system
improvements and further measurements planned for our return to the island in mid-2015 are
presented.
Acknowledgement
This work is supported by the Natural Environment Research Council Grant
NE/K005979/1. |
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