Improvement of microwave emissivity parameterization of frozen Arctic soils using roughness measurements derived from photogrammetry

Meloche, Julien, Royer, Alain, Langlois, Alexandre, Rutter, Nick and Sasseville, Vincent (2021) Improvement of microwave emissivity parameterization of frozen Arctic soils using roughness measurements derived from photogrammetry. International Journal of Digital Earth, 14 (10). pp. 1380-1396. ISSN 1753-8947

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Official URL: https://doi.org/10.1080/17538947.2020.1836049

Abstract

Soil emissivity of Arctic regions is a key parameter for assessing surface properties from microwave brightness temperature (Tb) measurements. Particularly in winter, frozen soil permittivity and roughness are two poorly characterized unknowns that must be considered. Here, we show that after removing snow, the 3D soil roughness can be accurately inferred from in-situ photogrammetry using Structure from Motion (SfM). We focus on using SfM techniques to provide accurate roughness measurements and improve emissivity models parametrization of frozen arctic soil for microwave applications. Validation was performed from ground-based radiometric measurements at 19 and 37 GHz using three different soil emission models: the Wegmüller and Mätzler [1999, TGRS] model (Weg99), the Wang and Choudhury [1981, JGR] model (QNH), and a geometrical optics model (Geo Optics). Measured and simulated brightness temperatures over different tundra and rock sites in the Canadian High Arctic show that Weg99, parametrized with SfM-based roughness and optimized permittivity (ε), yielded an RMSE of 3.1 K (R2=0.71) for all frequencies and polarizations. Our SfM based approach allowed us to measure roughness with 0.1 mm accuracy at 55 locations of different land cover type using a digital camera and metal plates of know dimensions.

Item Type: Article
Additional Information: Funding information: This research was made possible thanks to the financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC), Polar Knowledge Canada, Canada Foundation for Innovation (CFI), Fonds québécois de la recherche sur la nature et les technologies (FRQNT-Québec), Northern Scientific Training Program (NSTP), Environment and Climate Change Canada Grant and Contribution program and research funding from Northumbria University, UK.
Uncontrolled Keywords: Surface roughness, microwave remote sensing, frozen Arctic soil, SfM photogrammetry
Subjects: F600 Geology
F700 Ocean Sciences
F800 Physical and Terrestrial Geographical and Environmental Sciences
F900 Others in Physical Sciences
Department: Faculties > Engineering and Environment > Geography and Environmental Sciences
Depositing User: Rachel Branson
Date Deposited: 11 Oct 2020 11:48
Last Modified: 26 Oct 2021 03:30
URI: http://nrl.northumbria.ac.uk/id/eprint/44470

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