[en] In this work, Spire Global, Inc. carrier phase of GNSS dual-frequency reflected signals under grazing angle (GG-R) are used for sea surface altimetry over the Java Sea, Indonesia. Processing of 714 GG-R coherent profiles from January 2020 to October 2021 is carried out to retrieve the relative surface height from WGS84 applying two methods to remove the ionospheric delay: an ionosphere-free combination and smoothing of the frequency-specific correction based on dual-frequency carrier phase observations. A substantial improvement of ∼ 8 cm is observed in the root mean square error (RMSE) between the GG-R retrievals and the reference surface model using the frequency-specific ionospheric correction method.
MWStrassburg, BD Hamlington, RR Leben, Parluhutan Manurung, J Lumban Gaol, Bisman Nababan, Stefano Vignudelli, and K-Y Kim, "Sea level trends in Southeast Asian seas," Climate of the Past, vol. 11, no. 5, pp. 743-750, 2015.
Saleh Abdalla et al., "Altimetry for the future: Building on 25 years of progress," Advances in Space Research, vol. 68, no. 2, pp. 319-363, 2021, 25 Years of Progress in Radar Altimetry.
Weiqiang Li, Estel Cardellach, Fran Fabra, Antonio Rius, Serni Ribó, and Manuel Martín-Neira, "First spaceborne phase altimetry over sea ice using TechDemoSat-1 GNSS-R signals," Geophysical Research Letters, vol. 44, no. 16, pp. 8369-8376, 2017.
Vu A. Nguyen, Oleguer Nogués-Correig, Takayuki Yuasa, Dallas Masters, and Vladimir Irisov, "Initial GNSS Phase Altimetry Measurements From the Spire Satellite Constellation," Geophysical Research Letters, vol. 47, no. 15, 2020, e2020GL088308 10.1029/2020GL088308.
Raquel N. Buendía, Sajad Tabibi, and Matthieu Talpe, "Preliminary GNSS-R Altimetry in the Hudson Bay Based on Spire Grazing Angle Measurements," in IGARSS 2022-2022 IEEE International Geoscience and Remote Sensing Symposium, 2022, pp. 7135-7138.
D. Landskron and J. Böhm, "VMF3/GPT3: refined discrete and empirical troposphere mapping functions," Journal of Geodesy, , no. 92, pp. 349-360, 2018.
O. B. Andersen, A. Abulaitijiang, S. Zhang, and S. K. Rose, "A new high resolution Mean Sea Surface (DTU21MSS) for improved sea level monitoring," EGU General Assembly 2021, online, 19-30 Apr 2021, EGU21-16084, 2021.
Gary D. Egbert and Svetlana Y. Erofeeva, "Efficient Inverse Modeling of Barotropic Ocean Tides," Journal of Atmospheric and Oceanic Technology, vol. 19, no. 2, pp. 183-204, 2002.
William S Cleveland, Eric Grosse, andWilliamMShyu, "Local regression models," in Statistical models in S, pp. 309-376. Routledge, 2017.
Mary J Brodzik, Brendan Billingsley, Terry Haran, Bruce Raup, and Matthew H Savoie, "Ease-grid 2.0: Incremental but significant improvements for earthgridded data sets," ISPRS International Journal of Geo-Information, vol. 1, no. 1, pp. 32-45, 2012.
Craig J. Donlon, Robert Cullen, and Luisella Giulicchi et al., "The Copernicus Sentinel-6 mission: Enhanced continuity of satellite sea level measurements from space," Remote Sensing of Environment, vol. 258, pp. 112395, 2021.