Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data
Data of fully polarimetric synthetic aperture radar onboard Chandrayaan-2 make it feasible to analyze the geometric and physical properties of the lunar soil layer. A specific mission of Chandrayaan-2 is to investigate if there is water–ice in the regolith of the permanently shadowed regi...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2022-01-01
|
| Series: | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/9878095/ |
| _version_ | 1828147878718078976 |
|---|---|
| author | Niutao Liu Feng Xu Ya-Qiu Jin |
| author_facet | Niutao Liu Feng Xu Ya-Qiu Jin |
| author_sort | Niutao Liu |
| collection | DOAJ |
| description | Data of fully polarimetric synthetic aperture radar onboard Chandrayaan-2 make it feasible to analyze the geometric and physical properties of the lunar soil layer. A specific mission of Chandrayaan-2 is to investigate if there is water–ice in the regolith of the permanently shadowed region (PSR). Volatile substances are likely to accumulate in the ancient regolith media. Volumetric scattering of the regolith media might indicate specific characteristics of the regolith. Scattering from surface, rocks should be excluded. Such flat regions are difficult to identify in the digital elevation model. In this article, Chandrayaan-2 full-pol data at L-band are used for this purpose. The co-pol and cross-pol scattering coefficients and decomposition parameters, such as <italic>H</italic>, <inline-formula><tex-math notation="LaTeX">$\alpha $</tex-math></inline-formula>, degree of polarization, and circular polarization ratio of lunar surface, are studied. High-order scattering from rough surface is numerically simulated and analyzed by the bidirectional analytical ray-tracing code. It is found that rocky rough surface causes high co-pol scatterings. High-order scatterings of the rough surface and volumetric scatterers can enhance cross-pol scattering. Criteria are proposed to select volume scatterings at flat regions at Mare Serenitatis and a PSR crater. Regions with weak co-pol backscattering in a PSR crater at 85.9°N, 111.7°E are classified as flat surface. It is found that a flat region with weak co-pol and high cross-pol terms appears different from surrounding regions. The enhanced cross-pol is likely to be caused by volumetric inhomogeneity in the regolith. This unusual region shows its inhomogeneous soil layer and deserves further study. |
| first_indexed | 2024-04-11T21:06:48Z |
| format | Article |
| id | doaj.art-41cf07e8eb46498498f29fd7a2d8b35e |
| institution | Directory Open Access Journal |
| issn | 2151-1535 |
| language | English |
| last_indexed | 2024-04-11T21:06:48Z |
| publishDate | 2022-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| spelling | doaj.art-41cf07e8eb46498498f29fd7a2d8b35e2022-12-22T04:03:15ZengIEEEIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing2151-15352022-01-01157657766410.1109/JSTARS.2022.32045349878095Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR DataNiutao Liu0https://orcid.org/0000-0002-2015-7406Feng Xu1https://orcid.org/0000-0002-7015-1467Ya-Qiu Jin2https://orcid.org/0000-0001-6666-9151Key Laboratory of Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai, ChinaKey Laboratory of Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai, ChinaKey Laboratory of Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai, ChinaData of fully polarimetric synthetic aperture radar onboard Chandrayaan-2 make it feasible to analyze the geometric and physical properties of the lunar soil layer. A specific mission of Chandrayaan-2 is to investigate if there is water–ice in the regolith of the permanently shadowed region (PSR). Volatile substances are likely to accumulate in the ancient regolith media. Volumetric scattering of the regolith media might indicate specific characteristics of the regolith. Scattering from surface, rocks should be excluded. Such flat regions are difficult to identify in the digital elevation model. In this article, Chandrayaan-2 full-pol data at L-band are used for this purpose. The co-pol and cross-pol scattering coefficients and decomposition parameters, such as <italic>H</italic>, <inline-formula><tex-math notation="LaTeX">$\alpha $</tex-math></inline-formula>, degree of polarization, and circular polarization ratio of lunar surface, are studied. High-order scattering from rough surface is numerically simulated and analyzed by the bidirectional analytical ray-tracing code. It is found that rocky rough surface causes high co-pol scatterings. High-order scatterings of the rough surface and volumetric scatterers can enhance cross-pol scattering. Criteria are proposed to select volume scatterings at flat regions at Mare Serenitatis and a PSR crater. Regions with weak co-pol backscattering in a PSR crater at 85.9°N, 111.7°E are classified as flat surface. It is found that a flat region with weak co-pol and high cross-pol terms appears different from surrounding regions. The enhanced cross-pol is likely to be caused by volumetric inhomogeneity in the regolith. This unusual region shows its inhomogeneous soil layer and deserves further study.https://ieeexplore.ieee.org/document/9878095/Fully polarimetric (full-pol) synthetic aperture radarpermanently shadowed region (PSR)regolith mediasurface and volume scattering |
| spellingShingle | Niutao Liu Feng Xu Ya-Qiu Jin Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing Fully polarimetric (full-pol) synthetic aperture radar permanently shadowed region (PSR) regolith media surface and volume scattering |
| title | Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data |
| title_full | Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data |
| title_fullStr | Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data |
| title_full_unstemmed | Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data |
| title_short | Recognition of Volumetric Scattering of Lunar Regolith Media in the PSR via Fully Polarimetric SAR Data |
| title_sort | recognition of volumetric scattering of lunar regolith media in the psr via fully polarimetric sar data |
| topic | Fully polarimetric (full-pol) synthetic aperture radar permanently shadowed region (PSR) regolith media surface and volume scattering |
| url | https://ieeexplore.ieee.org/document/9878095/ |
| work_keys_str_mv | AT niutaoliu recognitionofvolumetricscatteringoflunarregolithmediainthepsrviafullypolarimetricsardata AT fengxu recognitionofvolumetricscatteringoflunarregolithmediainthepsrviafullypolarimetricsardata AT yaqiujin recognitionofvolumetricscatteringoflunarregolithmediainthepsrviafullypolarimetricsardata |