A New Methodology for Wheat Attenuation Correction at C-Band VV-Polarized Backscatter Time Series

Autor: Maria Arias, Miguel Angel Campo-Bescos, Luis Miguel Arregui, Maria Gonzalez-Audicana, Jesus Alvarez-Mozos
Přispěvatelé: Universidad Pública de Navarra. Departamento de Agronomía, Biotecnología y Alimentación, Universidad Pública de Navarra. Departamento de Ingeniería, Institute on Innovation and Sustainable Development in Food Chain - ISFOOD, Nafarroako Unibertsitate Publikoa. Agronomia, Bioteknologia eta Elikadura Saila, Nafarroako Unibertsitate Publikoa. Ingeniaritza Saila
Rok vydání: 2022
Předmět:
Zdroj: IEEE Transactions on Geoscience and Remote Sensing. 60:1-14
ISSN: 1558-0644
0196-2892
2019-1073
Popis: Wheat is one of the most important crops worldwide, and thus the use of remote sensing data for wheat monitoring has attracted much interest. Synthetic Aperture Radar (SAR) observations show that, at C-band and VV polarization, wheat canopy attenuates the surface scattering component from the underlying soil during a significant part of its growth cycle. This behavior needs to be accounted for or corrected before soil moisture retrieval is attempted. The objective of this paper is to develop a new method for wheat attenuation correction (WATCOR) applicable to Sentinel-1 VV time series and based solely on the information contained in the time series itself. The hypothesis of WATCOR is that without attenuation, VV backscatter would follow a stable long-term trend during the agricultural season, with short-term variations caused by soil moisture dynamics. The method relies on time series smoothing and changing point detection, and its implementation follows a series of simple steps. The performance of the method was compared by evaluating the correlation between backscatter and soil moisture content in six wheat fields with available soil moisture data. The Water Cloud Model (WCM) was also applied as a benchmark. The results showed that WATCOR successfully removed the attenuation in the time series, and achieved the highest correlation with soil moisture, improving markedly the correlation of the original backscatter. WATCOR can be easily implemented, as it does not require parameterization or any external data, only an approximate indication of the period where attenuation is likely to occur. This work was supported by the Spanish Ministry of Science and Innovation through project PID2019-107386RB-I00 / AEI / 10.13039/501100011033 and doctoral grant (BES-2017-080560).
Databáze: OpenAIRE
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