Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval
Soil moisture is one of the vital environmental variables in the land–atmosphere cycle. A study of the sensitivity analysis of bistatic scattering coefficients from bare soil at the Ku-band is presented, with the aim of deepening our understanding of the bistatic scattering features and exploring it...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-01-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/13/2/188 |
| _version_ | 1797415108922572800 |
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| author | Tingting Li Irena Hajnsek Kun-Shan Chen |
| author_facet | Tingting Li Irena Hajnsek Kun-Shan Chen |
| author_sort | Tingting Li |
| collection | DOAJ |
| description | Soil moisture is one of the vital environmental variables in the land–atmosphere cycle. A study of the sensitivity analysis of bistatic scattering coefficients from bare soil at the Ku-band is presented, with the aim of deepening our understanding of the bistatic scattering features and exploring its potential in soil moisture retrieval. First, a well-established advanced integral method was adopted for simulating the bistatic scattering response of bare soil. Secondly, a sensitivity index and a normalized weight quality index were proposed to evaluate the effect of soil moisture on the bistatic scattering coefficient in terms of polarization and angular diversity, and the combinations thereof. The results of single-polarized <i>VV</i> data show that the regions with the maximum sensitivity and high quality index, simultaneously, to soil moisture are in the forward off-specular direction. However, due to the effect of surface roughness and surface autocorrelation function (ACF), the single-polarized data have some limitations for soil moisture inversion. By contrast, the results of two different polarization combinations, as well as a dual-angular simulation of one transmitter and two receivers, show significant estimation benefits. It can be seen that they all provide better ACF suppression capabilities, larger high-sensitivity area, and higher quality indices compared to single-polarized estimation. In addition, dual polarization or dual angular combined measurement provides the possibility of retrieving soil moisture in backward regions. These results are expected to contribute to the design of future bistatic observation systems. |
| first_indexed | 2024-03-09T05:43:18Z |
| format | Article |
| id | doaj.art-8460e47b193d46d7b23b475c41a69e67 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-03-09T05:43:18Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-8460e47b193d46d7b23b475c41a69e672023-12-03T12:23:13ZengMDPI AGRemote Sensing2072-42922021-01-0113218810.3390/rs13020188Sensitivity Analysis of Bistatic Scattering for Soil Moisture RetrievalTingting Li0Irena Hajnsek1Kun-Shan Chen2Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, ChinaInstitute of Environmental Engineering, ETH Zurich, 8093 Zurich, SwitzerlandCollege of Geomantic and Geoinformation, Guilin University of Technology, Guilin 541004, ChinaSoil moisture is one of the vital environmental variables in the land–atmosphere cycle. A study of the sensitivity analysis of bistatic scattering coefficients from bare soil at the Ku-band is presented, with the aim of deepening our understanding of the bistatic scattering features and exploring its potential in soil moisture retrieval. First, a well-established advanced integral method was adopted for simulating the bistatic scattering response of bare soil. Secondly, a sensitivity index and a normalized weight quality index were proposed to evaluate the effect of soil moisture on the bistatic scattering coefficient in terms of polarization and angular diversity, and the combinations thereof. The results of single-polarized <i>VV</i> data show that the regions with the maximum sensitivity and high quality index, simultaneously, to soil moisture are in the forward off-specular direction. However, due to the effect of surface roughness and surface autocorrelation function (ACF), the single-polarized data have some limitations for soil moisture inversion. By contrast, the results of two different polarization combinations, as well as a dual-angular simulation of one transmitter and two receivers, show significant estimation benefits. It can be seen that they all provide better ACF suppression capabilities, larger high-sensitivity area, and higher quality indices compared to single-polarized estimation. In addition, dual polarization or dual angular combined measurement provides the possibility of retrieving soil moisture in backward regions. These results are expected to contribute to the design of future bistatic observation systems.https://www.mdpi.com/2072-4292/13/2/188bistatic scattering coefficientsensitivity analysissoil moisture retrieval |
| spellingShingle | Tingting Li Irena Hajnsek Kun-Shan Chen Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval Remote Sensing bistatic scattering coefficient sensitivity analysis soil moisture retrieval |
| title | Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval |
| title_full | Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval |
| title_fullStr | Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval |
| title_full_unstemmed | Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval |
| title_short | Sensitivity Analysis of Bistatic Scattering for Soil Moisture Retrieval |
| title_sort | sensitivity analysis of bistatic scattering for soil moisture retrieval |
| topic | bistatic scattering coefficient sensitivity analysis soil moisture retrieval |
| url | https://www.mdpi.com/2072-4292/13/2/188 |
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