Development and Application of a GNSS-R Error Model for Hurricane Winds

Autor: Rajeswari Balasubramaniam, Christopher S. Ruf
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, Vol 17, Pp 2336-2346 (2024)
Druh dokumentu: article
ISSN: 2151-1535
DOI: 10.1109/JSTARS.2023.3344371
Popis: A parametric error model is developed to represent the uncertainty in retrieval of hurricane force wind speed by a spaceborne GNSS-R instrument. The functional form of the model is constructed based on a bottom–up consideration of the primary contributing sources of uncertainty. Scaling parameters in the model are tuned in a top–down manner using a large population of wind speed retrievals by the CYGNSS satellite, which are colocated in space and time with HWRF reanalysis hurricane winds in the North Atlantic during 2018–2022. The root-mean-squared difference between CYGNSS and HWRF winds is found to depend on a number of variables, two of which are wind speed and receive antenna gain. The parametrized error model represents these dependencies. The model can be used as a design tool to predict expected performance as a function of instrument design. In particular, the model predicts the antenna gain required to achieve a particular level of wind speed uncertainty at a particular wind speed. A case study is considered in which a receive antenna gain of at least 20 dBi is found to be required to reliably distinguish between a Category 4 and Category 5 hurricane. This has implications for the optimal design of a future GNSS-R instrument intended for hurricane observations.
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