cam a22 4 4500 569280117 CHVBK 20201202100955.0 190725s2019 sz a m 00 0deng d urn:nbn:ch:bel-1578920 urn (SNL)991017971607903976 (SNL)991018070807903976 (NEBIS)011435262 (Sz)991017971607903976 (Sz)991018070807903976 Sz ger rda eng eng ger 520 23sdnb 550 23sdnb Steiner Ladina 1987- (DE-588)1188584316 Verfasser aut Snow water equivalent observations using refracted GPS signals presented by Ladina Cristina Steiner Zurich 2019 ix, 109 Seiten Illustrationen 30 cm Dissertation No. 25902 ETH Zurich, 2019 Literaturverzeichnis application/pdf 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. Englischer Text mit englischer und deutscher Zusammenfassung GLOBAL NAVIGATION SATELLITE SYSTEM, GNSS (GEODÄSIE) ger (ETHUDK)000067159 ethudk REMOTE SENSING + FERNMESSUNG + FERNERKUNDUNG (GEODÄSIE) ger (ETHUDK)000055589 ethudk WASSERVORRAT AUS NIEDERSCHLÄGEN, SCHNEEDECKE UND GLETSCHER (HYDROMETEOROLOGIE) ger (ETHUDK)000059517 ethudk WASSERVORRAT AUS SCHNEESCHMELZE (METEOROLOGIE) ger (ETHUDK)000020408 ethudk WASSERVORRÄTE (WASSERVERSORGUNG) ger (ETHUDK)000020407 ethudk Hochschulschrift (DE-588)4113937-9 gnd-content Hochschulschrift gnd-content sb 2019/15 520 zh snl-sb xehelv xediss 2020 550 snl ehelv u WASSERVORRAT AUS SCHNEESCHMELZE (METEOROLOGIE) ger 551.579.2 nebis E1 u WASSERVORRAT AUS NIEDERSCHLÄGEN, SCHNEEDECKE UND GLETSCHER (HYDROMETEOROLOGIE) ger 551.579.1/.3 nebis E1 u WASSERVORRÄTE (WASSERVERSORGUNG) ger 628.1*1 nebis E1 u GLOBAL NAVIGATION SATELLITE SYSTEM, GNSS (GEODÄSIE) ger 528.28%629.783 nebis E1 u REMOTE SENSING + FERNMESSUNG + FERNERKUNDUNG (GEODÄSIE) ger 528.8 nebis E1 u WATER SUPPLY FROM SNOW COVER, SNOW MELT (METEOROLOGY) eng 551.579.2 nebis E1 u APPROVISIONNEMENT EN EAU PAR LA MOYEN DE LA FONTE DES NEIGES (MÉTÉOROLOGIE) fre 551.579.2 nebis E1 u APPROVISIONNEMENT EN EAU PAR LE MOYEN DES PRÉCIPATATIONS, DE LA FONTE DES NEIGES ET DES GLACIERS (HYDROMÉTÉOROLOGIE) fre 551.579.1/.3 nebis E1 u WATER SUPPLY FROM PRECIPITATION, SNOW COVER AND GLACIERS (HYDROMETEOROLOGY) eng 551.579.1/.3 nebis E1 u WATER RESOURCES (WATER SUPPLY) eng 628.1*1 nebis E1 u RESSOURCES EN EAU (APPROVISIONNEMENT EN EAU) fre 628.1*1 nebis E1 u GLOBAL NAVIGATION SATELLITE SYSTEM, GNSS (GEODESY) eng 528.28%629.783 nebis E1 u GLOBAL NAVIGATION SATELLITE SYSTEM, GNSS (GÉODÉSIE) fre 528.28%629.783 nebis E1 u TÉLÉMESURE + TÉLÉMÉTRIE + TÉLÉDÉTECTION (GÉODÉSIE) fre 528.8 nebis E1 u REMOTE SENSING (GEODESY) eng 528.8 nebis E1 Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL NB001 NB999 - chb99 - https://opac.admin.ch/toc/toc1902090131.pdf Inhaltsverzeichnis BK020300 XK020000 XK020000 077 E01-20190624 076 E01-20190624 079 E01-20190624 SNL NB001 NB001 Nbq 121760 NB10010 NEBIS E16 E16 RH Diss ETH 25902 SNL 100 1- Steiner Ladina 1987- (DE-588)1188584316 Verfasser aut SNL 856 41 https://opac.admin.ch/toc/toc1902090131.pdf Inhaltsverzeichnis SNL 710 2- Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL 100 1- Steiner Ladina Verfasser aut SNL 856 40 http://hdl.handle.net/20.500.11850/345249 SNL 856 4- https://nbn-resolving.org/urn:nbn:ch:bel-1578920 SNL 856 42 http://www.e-helvetica.nb.admin.ch/directAccess?callnumber=bel-1578920 NEBIS 100 1- Steiner Ladina 1987- (DE-588)1188584316 Verfasser aut NEBIS 700 1- Geiger Alain 1954- (DE-588)1089268556 Akademischer Betreuer dgs NEBIS 700 1- Rothacher Markus 1957- (DE-588)1089566174 Akademischer Betreuer dgs NEBIS 700 1- Kääb Andreas (DE-588)1067818057 Akademischer Betreuer dgs