TY - JOUR
T1 - Water level measurements using reflected GNSS signals
AU - Larson, K. M.
AU - Williams, S. D. P.
JO - The International Hydrographic Review
VL - 29(2)
SP - 66
EP - 76
PY - 2023
DA - 2023/11/30
DO - https://doi.org/10.58440/ihr-29-2-a30
UR - https://ihr.iho.int/articles/water-level-measurements-using-reflected-gnss-signals/
KW - GNSS
KW - GNSS interferometric reflectometry
KW - open source software
KW - river level monitoring
KW - tide gauge
AB - GNSS Interferometric Reflectometry (GNSS-IR) is a method that can be used to measure water levels. The frequency of the interference pattern created by direct and reflected GNSS signals is used to estimate the height of the GNSS antenna above the reflecting surface. In principle each rising and setting satellite arc that reflects off the water can be used, yielding ~350 water level measurements per day at sites that track the four major constellations and have a good view of the water. Two examples of the GNSS-IR method are presented, one at a coastal site in Australia and the other from the Ems river in Germany. Each site has collocated traditional tide gauge instrumentation. Open source GNSS-IR software is used to analyze the GNSS data from each site. Correlations between GNSS-IR with the traditional gauge are shown to be better than 0.99.