Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica: Challenges and Opportunities

Shashwat Shukla; Bert Wouters; Ghislain Picard; Nander Wever; Maaike Izeboud; Sophie de Roda Husman; Thore Kausch; Sanne Veldhuijsen; Christian Matzler; Stef Lhermitte

doi:10.1109/JSTARS.2024.3438233

Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica: Challenges and Opportunities

Shashwat Shukla
, Bert Wouters
, Ghislain Picard
, Nander Wever
, Maaike Izeboud
, Sophie de Roda Husman
, Thore Kausch
, Sanne Veldhuijsen
, Christian Matzler
, Stef Lhermitte

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

Assessing the Surface Mass Balance (SMB) of the Antarctic Ice Sheet is crucial for understanding its response to climate change. Synthetic Aperture Radar observations from Sentinel-1 provide the potential to monitor the variability of SMB processes through changes in the scattering response of near-surface and internal snow layers. However, the interplay between several factors, such as accumulation, wind erosion, deposition, and melt, complicates the interpretation of scattering changes of the microwave signal. Additionally, lack of reliable ground truth measurements of the snow surface limits our capability to associate the SMB processes with dominant scattering mechanism. In this study, we aim to quantify the dominant scattering in Sentinel-1 signal and evaluate the scattering changes in drifting snow-dominated regions of East Antarctica. We introduce a scattering indicator, alpha -{text{scat},varepsilon }, derived from scattering-type and entropy descriptors, providing a measure between volume and pure scattering. By relating the field measurements to alpha -{text{scat},varepsilon }, we establish that the evolution of dominant scattering in the presence of snowdrift is complex. First, alpha -{text{scat},varepsilon } strongly correlates with surface roughness (R^{2}=0.92, RMSE =2^circ). Spatially variable erosion patterns significantly increase the roughness and result in a strong affinity towards pure scattering despite net accumulation. Second, high surface densities also tend to influence pure scattering; however, the effect is dependent on the accumulation rate. With more accumulation, we observe an increasing dominance of volume scattering from internal snow layers. Long-term trends in alpha -{text{scat},varepsilon } (2017/2023) further suggest that it is challenging to address the causes behind the scattering source based on a single snow surface process. We thus demonstrate the potential and limitations of alpha -{text{scat},varepsilon } to infer the variability in dominant scattering from changes in surface processes.

Original language	English
Pages (from-to)	14380-14393
Number of pages	14
Journal	IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Volume	17
Early online date	5 Aug 2024
DOIs	https://doi.org/10.1109/JSTARS.2024.3438233
Publication status	Published - 2024

Bibliographical note

Publisher Copyright:
© 2008-2012 IEEE.

Funding

The work of Shashwat Shukla, Sophie de Roda Husman, and Sanne Veldhuijsen was supported by Nederlandse Organisatie voor Wetenschap-pelijk Onderzoek (NWO) under grant no. OCENW.GROOT.2019.091. The work of Maaike Izeboud was supported by the NWO under grant no. ALWGO.2018.043. The work of Thore Kausch was supported by the NWO under grant no. AL-WPT.2016.4. (Corresponding author: Shashwat Shukla.) Shashwat Shukla, Bert Wouters, Maaike Izeboud, Sophie de Roda Husman and Thore Kausch are with the Department of Geoscience and Remote Sensing, Delft University of Technology, 2628 CD Delft, The Netherlands (email: [email protected]; [email protected]; [email protected], [email protected]; [email protected]). We acknowledge the International Polar Foundation for supporting the logistics during the field campaigns at HAM and LIR sites. The 2018/19 and 2021/22 field campaigns are part of Mass2Ant project funded by the Netherlands Organisation for Scientific Research (grant no. AL-WPT.2016.4), the Belgian Federal Science Policy Office (grant no. BR/165/A2:Mass2Ant), and the National Aeronautics and Space Administration (grant no. 80NSSC18K0201). Additionally, we sincerely acknowledge Prof. Roland Klees from TU Delft for his significant help and support in the frequency domain analysis of TLS data to derive the roughness information. We also thank the reviewers for their helpful and thorough comments.

Funders	Funder number
Sophie de Roda Husman
Belgian Federal Science Policy Office
Shashwat Shukla
National Aeronautics and Space Administration	80NSSC18K0201
National Aeronautics and Space Administration
Nederlandse Organisatie voor Wetenschap-pelijk Onderzoek	OCENW.GROOT.2019.091
Nederlandse Organisatie voor Wetenschappelijk Onderzoek	AL-WPT.2016.4
Nederlandse Organisatie voor Wetenschappelijk Onderzoek

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 13 Climate Action

Keywords

Antarctica
Climate change
Rough surfaces
SMB processes
Scattering
Sea surface
Sentinel-1
Snow
Surface impedance
Surface roughness
Surface treatment

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Cite this

Shukla, S., Wouters, B., Picard, G., Wever, N., Izeboud, M., Husman, S. D. R., Kausch, T., Veldhuijsen, S., Matzler, C., & Lhermitte, S. (2024). Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica: Challenges and Opportunities. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 17, 14380-14393. https://doi.org/10.1109/JSTARS.2024.3438233

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abstract = "Assessing the Surface Mass Balance (SMB) of the Antarctic Ice Sheet is crucial for understanding its response to climate change. Synthetic Aperture Radar observations from Sentinel-1 provide the potential to monitor the variability of SMB processes through changes in the scattering response of near-surface and internal snow layers. However, the interplay between several factors, such as accumulation, wind erosion, deposition, and melt, complicates the interpretation of scattering changes of the microwave signal. Additionally, lack of reliable ground truth measurements of the snow surface limits our capability to associate the SMB processes with dominant scattering mechanism. In this study, we aim to quantify the dominant scattering in Sentinel-1 signal and evaluate the scattering changes in drifting snow-dominated regions of East Antarctica. We introduce a scattering indicator, alpha -\{text\{scat\},varepsilon \}, derived from scattering-type and entropy descriptors, providing a measure between volume and pure scattering. By relating the field measurements to alpha -\{text\{scat\},varepsilon \}, we establish that the evolution of dominant scattering in the presence of snowdrift is complex. First, alpha -\{text\{scat\},varepsilon \} strongly correlates with surface roughness (R\textasciicircum{}\{2\}=0.92, RMSE =2\textasciicircum{}circ). Spatially variable erosion patterns significantly increase the roughness and result in a strong affinity towards pure scattering despite net accumulation. Second, high surface densities also tend to influence pure scattering; however, the effect is dependent on the accumulation rate. With more accumulation, we observe an increasing dominance of volume scattering from internal snow layers. Long-term trends in alpha -\{text\{scat\},varepsilon \} (2017/2023) further suggest that it is challenging to address the causes behind the scattering source based on a single snow surface process. We thus demonstrate the potential and limitations of alpha -\{text\{scat\},varepsilon \} to infer the variability in dominant scattering from changes in surface processes.",

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author = "Shashwat Shukla and Bert Wouters and Ghislain Picard and Nander Wever and Maaike Izeboud and Husman, \{Sophie de Roda\} and Thore Kausch and Sanne Veldhuijsen and Christian Matzler and Stef Lhermitte",

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doi = "10.1109/JSTARS.2024.3438233",

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Shukla, S, Wouters, B, Picard, G, Wever, N, Izeboud, M, Husman, SDR, Kausch, T, Veldhuijsen, S, Matzler, C & Lhermitte, S 2024, 'Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica: Challenges and Opportunities', IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 17, pp. 14380-14393. https://doi.org/10.1109/JSTARS.2024.3438233

TY - JOUR

T1 - Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica

T2 - Challenges and Opportunities

AU - Shukla, Shashwat

AU - Wouters, Bert

AU - Picard, Ghislain

AU - Wever, Nander

AU - Izeboud, Maaike

AU - Husman, Sophie de Roda

AU - Kausch, Thore

AU - Veldhuijsen, Sanne

AU - Matzler, Christian

AU - Lhermitte, Stef

PY - 2024

Y1 - 2024

N2 - Assessing the Surface Mass Balance (SMB) of the Antarctic Ice Sheet is crucial for understanding its response to climate change. Synthetic Aperture Radar observations from Sentinel-1 provide the potential to monitor the variability of SMB processes through changes in the scattering response of near-surface and internal snow layers. However, the interplay between several factors, such as accumulation, wind erosion, deposition, and melt, complicates the interpretation of scattering changes of the microwave signal. Additionally, lack of reliable ground truth measurements of the snow surface limits our capability to associate the SMB processes with dominant scattering mechanism. In this study, we aim to quantify the dominant scattering in Sentinel-1 signal and evaluate the scattering changes in drifting snow-dominated regions of East Antarctica. We introduce a scattering indicator, alpha -{text{scat},varepsilon }, derived from scattering-type and entropy descriptors, providing a measure between volume and pure scattering. By relating the field measurements to alpha -{text{scat},varepsilon }, we establish that the evolution of dominant scattering in the presence of snowdrift is complex. First, alpha -{text{scat},varepsilon } strongly correlates with surface roughness (R^{2}=0.92, RMSE =2^circ). Spatially variable erosion patterns significantly increase the roughness and result in a strong affinity towards pure scattering despite net accumulation. Second, high surface densities also tend to influence pure scattering; however, the effect is dependent on the accumulation rate. With more accumulation, we observe an increasing dominance of volume scattering from internal snow layers. Long-term trends in alpha -{text{scat},varepsilon } (2017/2023) further suggest that it is challenging to address the causes behind the scattering source based on a single snow surface process. We thus demonstrate the potential and limitations of alpha -{text{scat},varepsilon } to infer the variability in dominant scattering from changes in surface processes.

AB - Assessing the Surface Mass Balance (SMB) of the Antarctic Ice Sheet is crucial for understanding its response to climate change. Synthetic Aperture Radar observations from Sentinel-1 provide the potential to monitor the variability of SMB processes through changes in the scattering response of near-surface and internal snow layers. However, the interplay between several factors, such as accumulation, wind erosion, deposition, and melt, complicates the interpretation of scattering changes of the microwave signal. Additionally, lack of reliable ground truth measurements of the snow surface limits our capability to associate the SMB processes with dominant scattering mechanism. In this study, we aim to quantify the dominant scattering in Sentinel-1 signal and evaluate the scattering changes in drifting snow-dominated regions of East Antarctica. We introduce a scattering indicator, alpha -{text{scat},varepsilon }, derived from scattering-type and entropy descriptors, providing a measure between volume and pure scattering. By relating the field measurements to alpha -{text{scat},varepsilon }, we establish that the evolution of dominant scattering in the presence of snowdrift is complex. First, alpha -{text{scat},varepsilon } strongly correlates with surface roughness (R^{2}=0.92, RMSE =2^circ). Spatially variable erosion patterns significantly increase the roughness and result in a strong affinity towards pure scattering despite net accumulation. Second, high surface densities also tend to influence pure scattering; however, the effect is dependent on the accumulation rate. With more accumulation, we observe an increasing dominance of volume scattering from internal snow layers. Long-term trends in alpha -{text{scat},varepsilon } (2017/2023) further suggest that it is challenging to address the causes behind the scattering source based on a single snow surface process. We thus demonstrate the potential and limitations of alpha -{text{scat},varepsilon } to infer the variability in dominant scattering from changes in surface processes.

KW - Antarctica

KW - Climate change

KW - Rough surfaces

KW - SMB processes

KW - Scattering

KW - Sea surface

KW - Sentinel-1

KW - Snow

KW - Surface impedance

KW - Surface roughness

KW - Surface treatment

UR - https://www.scopus.com/pages/publications/85200798989

U2 - 10.1109/JSTARS.2024.3438233

DO - 10.1109/JSTARS.2024.3438233

M3 - Article

AN - SCOPUS:85200798989

SN - 1939-1404

VL - 17

SP - 14380

EP - 14393

JO - IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

JF - IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

ER -

Large Variability in Dominant Scattering from Sentinel-1 SAR in East Antarctica: Challenges and Opportunities

Abstract

Bibliographical note

Funding

UN SDGs

Keywords

Access to Document

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