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dc.contributor.author
Steiner, Ladina
dc.contributor.supervisor
Geiger, Alain
dc.contributor.supervisor
Rothacher, Markus
dc.contributor.supervisor
Kääb, Andreas
dc.date.accessioned
2020-09-24T06:14:10Z
dc.date.available
2019-06-03T13:03:56Z
dc.date.available
2019-06-03T13:23:04Z
dc.date.available
2019-07-15T11:07:32Z
dc.date.available
2019-07-15T12:06:10Z
dc.date.available
2019-07-15T12:07:57Z
dc.date.available
2019-07-15T14:01:17Z
dc.date.available
2020-09-24T06:14:10Z
dc.date.issued
2019-06
dc.identifier.uri
http://hdl.handle.net/20.500.11850/345249
dc.identifier.doi
10.3929/ethz-b-000345249
dc.description.abstract
An extensive amount of water is stored in snow covers, which has a high impact on flood development during snow melting periods. Early assessment of the snow water equivalent (SWE) in mountain environments enhances early-warning and thus prevention of major impacts. SWE is one essential climate variable and the knowledge about the water storage in mountain catchment areas has a high significance for the global water and energy supply, especially for regions depending on the snow melt. The main objective of this thesis is a thorough investigation of the contribution of geodetic GNSS remote sensing techniques to observe and quantify mountainous SWE. This investigation is based on differential GPS processing using refracted GPS phase signals received by commercially available off-the-shelf GPS antennas buried underneath a typical Alpine snowpack. The main tasks are: a) Identification of the theoretical and empirical characteristics and limitations of GPS L1 single-frequency observations using submerged GPS antennas, as well as the development of a mathematical model for SWE estimation (Paper I); b) Application of the developed model to an Alpine seasonal snowpack and investigation of the potential for SWE quantification (Paper II); c) Identification of the main impact of GPS processing on the accuracy of the derived SWE estimates when using refracted GPS signals (Paper III). Further evaluation is based on the possibility of using low-cost GPS equipment for SWE quantification (Paper IV). Liquid water is expected theoretically to exert the largest influence on a GPS signal propagation through a snowpack. An experimental setup has been established to investigate the influence of liquid water on the GPS observations by testing water levels up to the signal penetration depth of 35mm above the antenna. Results correspond well with theory and the water level above the submerged antenna can be estimated using the derived model with sub-millimetre accuracy. The potential of using refracted GPS signals for SWE estimation has been evaluated based on an experimental setup at an Alpine snowpack. A measurement network has been installed, consisting of a GPS reference station above the snowpack and a GPS antenna mounted on the ground underneath the snowpack. The empirical SWE results are validated against the state-of-the-art reference sensors, i.e., the snow pillow, snow scale, and manual observations over three seasons (2015/16 – 2017/18). The comparison shows a high level of agreement with a relative bias below 5% (RMSE of 38mmw.e.) over all three seasons, including the melting periods. SWE could be accurately estimated with a high temporal resolution of one hour. The applied ambiguity resolution strategy and the selection of an elevation cut-off angle and a weighting function could be identified as the three most important GPS processing options influencing the quality of the resulting SWE estimates.
en_US
dc.format
application/pdf
en_US
dc.language.iso
en
en_US
dc.publisher
ETH Zurich
en_US
dc.rights.uri
http://rightsstatements.org/page/InC-NC/1.0/
dc.subject
GNSS
en_US
dc.subject
GNSS signal propagation in snow, ice, water
en_US
dc.subject
Snow water equivalent
en_US
dc.subject
Geodesy
en_US
dc.subject
Snow Science
en_US
dc.subject
Cryospheric science
en_US
dc.title
Snow Water Equivalent Observations Using Refracted GPS Signals
en_US
dc.type
Doctoral Thesis
dc.rights.license
In Copyright - Non-Commercial Use Permitted
dc.date.published
2019-06-03
ethz.size
71 p.
en_US
ethz.code.ddc
DDC - DDC::5 - Science::550 - Earth sciences
en_US
ethz.grant
GNSS Remote Sensing of snow coverage on ground and glacier surfaces
en_US
ethz.identifier.diss
25902
en_US
ethz.publication.place
Zurich
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02115 - Dep. Bau, Umwelt und Geomatik / Dep. of Civil, Env. and Geomatic Eng.::02647 - Inst. f. Geodäsie und Photogrammetrie / Institute of Geodesy and Photogrammetry::03824 - Rothacher, Markus / Rothacher, Markus
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02115 - Dep. Bau, Umwelt und Geomatik / Dep. of Civil, Env. and Geomatic Eng.::02647 - Inst. f. Geodäsie und Photogrammetrie / Institute of Geodesy and Photogrammetry::03824 - Rothacher, Markus / Rothacher, Markus
en_US
ethz.grant.agreementno
156867
ethz.grant.fundername
SNF
ethz.grant.funderDoi
10.13039/501100001711
ethz.grant.program
Projekte MINT
ethz.relation.cites
10.5194/tc-12-3161-2018
ethz.relation.cites
10.1007/s00190-018-1147-x
ethz.relation.cites
https://ieeexplore.ieee.org/document/8739896
ethz.relation.cites
https://ieeexplore.ieee.org/document/8826580
ethz.date.deposited
2019-06-03T13:04:04Z
ethz.source
FORM
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2019-06-03T13:23:39Z
ethz.rosetta.lastUpdated
2022-03-29T03:12:00Z
ethz.rosetta.versionExported
true
ethz.COinS
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