Dielectric properties estimation of the lunar regolith at CE-3 landing site using lunar penetrating radar data

Icarus ◽  
2017 ◽  
Vol 284 ◽  
pp. 424-430 ◽  
Author(s):  
Jianqing Feng ◽  
Yan Su ◽  
Chunyu Ding ◽  
Shuguo Xing ◽  
Shun Dai ◽  
...  
2021 ◽  
Author(s):  
Hanjie Song ◽  
Hui Sun ◽  
Gang Yu ◽  
Yang Liu ◽  
Juan Li ◽  
...  

Abstract The Lunar Regolith Penetrating Radar (LRPR) on the Chang’E-5 (CE-5) lander was deployed to investigate structures of the regolith. The migration and ridge detection methods were used to process the radar data, and the results indicate a 4.5 m regolith thickness that contains four units at the landing site, which is characterized by different internal reflections that point to their various compositions, mainly comprise protolith and admixed ejecta from the Harpalus, Copernicus, and Aristarchus. High-resolution processing for the LRPR data indicates a few rocks or slates with depth from ~ 0.2 m to over 1 m in the subsurface at the landing site, which was validated by the force analysis during the drilling of the regolith into ~ 1 m depth. The processing procedure proposed in this study is capable of producing reliable and precise images of the lunar regolith substructure, which provides important geological context on the returned drilling samples.


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2907 ◽  
Author(s):  
Ling Zhang ◽  
Zhaofa Zeng ◽  
Jing Li ◽  
Ling Huang ◽  
Zhijun Huo ◽  
...  

Parameter estimation of the lunar regolith not only provides important information about the composition but is also critical to quantifying potential resources for lunar exploration and engineering for human outposts. The Lunar Penetrating Radar (LPR) onboard China’s Chang’E-3 (CE-3) provides a unique opportunity for mapping the near-surface stratigraphic structure and estimating the parameters of the regolith. In this paper, the electrical parameters and the iron-titanium content of regolith are estimated based on the two sets of LPR data. Firstly, it is theoretically verified that the relative dielectric constant can be estimated according to the difference of the reflected time of two receivers from a same target. Secondly, in order to verify the method, a parameter estimation flow is designed. Subsequently, a simple model and a complex model of regolith are carried out for the method verification. Finally, on the basis of the two sets of LPR data, the electrical parameters and the iron-titanium content of regolith are estimated. The relative dielectric constant of regolith at CE-3 landing site is 3.0537 and the content of TiO2 and FeO is 14.0127%. This helps us predict the reserves of resources at the CE-3 landing site and even in the entire Mare Imbrium.


2018 ◽  
Vol 10 (12) ◽  
pp. 1925 ◽  
Author(s):  
Kun Wang ◽  
Zhaofa Zeng ◽  
Ling Zhang ◽  
Shugao Xia ◽  
Jing Li

Lunar Penetrating Radar (LPR) is one of the important scientific systems onboard the Yutu lunar rover for the purpose of detecting the lunar regolith and the subsurface geologic structures of the lunar regolith, providing the opportunity to map the subsurface structure and vertical distribution of the lunar regolith with a high resolution. In this paper, in order to improve the capability of identifying response signals caused by discrete reflectors (such as meteorites, basalt debris, etc.) beneath the lunar surface, we propose a compressive sensing (CS)-based approach to estimate the amplitudes and time delays of the radar signals from LPR data. In this approach, the total-variation (TV) norm was used to estimate the signal parameters by a set of Fourier series coefficients. For this, we chose a nonconsecutive and random set of Fourier series coefficients to increase the resolution of the underlying target signal. After a numerical analysis of the performance of the CS algorithm, a complicated numerical example using a 2D lunar regolith model with clipped Gaussian random permittivity was established to verify the validity of the CS algorithm for LPR data. Finally, the compressive sensing-based approach was applied to process 500-MHz LPR data and reconstruct the target signal’s amplitudes and time delays. In the resulting image, it is clear that the CS-based approach can improve the identification of the target’s response signal in a complex lunar environment.


2020 ◽  
Vol 13 (1) ◽  
pp. 48
Author(s):  
Hanjie Song ◽  
Chao Li ◽  
Jinhai Zhang ◽  
Xing Wu ◽  
Yang Liu ◽  
...  

The Lunar Penetrating Radar (LPR) onboard the Yutu-2 rover from China’s Chang’E-4 (CE-4) mission is used to probe the subsurface structure and the near-surface stratigraphic structure of the lunar regolith on the farside of the Moon. Structural analysis of regolith could provide abundant information on the formation and evolution of the Moon, in which the rock location and property analysis are the key procedures during the interpretation of LPR data. The subsurface velocity of electromagnetic waves is a vital parameter for stratigraphic division, rock location estimates, and calculating the rock properties in the interpretation of LPR data. In this paper, we propose a procedure that combines the regolith rock extraction technique based on local correlation between the two sets of LPR high-frequency channel data and the common offset semblance analysis to determine the velocity from LPR diffraction hyperbola. We consider the heterogeneity of the regolith and derive the relative permittivity distribution based on the rock extraction and semblance analysis. The numerical simulation results show that the procedure is able to obtain the high-precision position and properties of the rock. Furthermore, we apply this procedure to CE-4 LPR data and obtain preferable estimations of the rock locations and the properties of the lunar subsurface regolith.


Author(s):  
Honglei Lin ◽  
Shuai Li ◽  
Yangting Lin ◽  
Yang Liu ◽  
Yong Wei ◽  
...  

2015 ◽  
Vol 112 (17) ◽  
pp. 5342-5347 ◽  
Author(s):  
Jinhai Zhang ◽  
Wei Yang ◽  
Sen Hu ◽  
Yangting Lin ◽  
Guangyou Fang ◽  
...  

We report the surface exploration by the lunar rover Yutu that landed on the young lava flow in the northeastern part of the Mare Imbrium, which is the largest basin on the nearside of the Moon and is filled with several basalt units estimated to date from 3.5 to 2.0 Ga. The onboard lunar penetrating radar conducted a 114-m-long profile, which measured a thickness of ∼5 m of the lunar regolith layer and detected three underlying basalt units at depths of 195, 215, and 345 m. The radar measurements suggest underestimation of the global lunar regolith thickness by other methods and reveal a vast volume of the last volcano eruption. The in situ spectral reflectance and elemental analysis of the lunar soil at the landing site suggest that the young basalt could be derived from an ilmenite-rich mantle reservoir and then assimilated by 10–20% of the last residual melt of the lunar magma ocean.


1997 ◽  
Vol 24 ◽  
pp. 355-360 ◽  
Author(s):  
Jack Kohler ◽  
John Moore ◽  
Mike Kennett ◽  
Rune Engeset ◽  
Hallgeir Elvehøy

In traditional mass-balance measurements one estimates winter snow accumulation by identifying the depth to the previous summer’s snow or ice surface using a snow probe. This is labor-intensive and unreliable for inhomogeneous summer surfaces. Another method is to image internal reflection horizons using a ground-penetrating radar (GPR), which has advantages in speed and areal coverage over traditional probing. However, to obtain quantitative mass-balance measurements from GPR images one needs to convert the time scale to a depth scale, not a straightforward problem. We compare a GPR section with dielectric profiles and visual stratigraphy of three snow cores, manual probings, and previous mass-balance measurements. We relate changes in snow-core dielectric properties to changes in density and to the travel times of reflecting horizons in the GPR section, and correlate some of these reflecting horizons with previous summer surfaces. We conclude that GPR can be used as a complementary tool in mass-balance measurements, giving a wide areal survey of winter accumulation and net balance for preceding years. However, proper calibration is essential for identifying specific surfaces in the radar data.


Author(s):  
Jinhai Zhang ◽  
Bin Zhou ◽  
Yangting Lin ◽  
Meng-Hua Zhu ◽  
Hanjie Song ◽  
...  

1997 ◽  
Vol 24 ◽  
pp. 355-360 ◽  
Author(s):  
Jack Kohler ◽  
John Moore ◽  
Mike Kennett ◽  
Rune Engeset ◽  
Hallgeir Elvehøy

In traditional mass-balance measurements one estimates winter snow accumulation by identifying the depth to the previous summer’s snow or ice surface using a snow probe. This is labor-intensive and unreliable for inhomogeneous summer surfaces. Another method is to image internal reflection horizons using a ground-penetrating radar (GPR), which has advantages in speed and areal coverage over traditional probing. However, to obtain quantitative mass-balance measurements from GPR images one needs to convert the time scale to a depth scale, not a straightforward problem. We compare a GPR section with dielectric profiles and visual stratigraphy of three snow cores, manual probings, and previous mass-balance measurements. We relate changes in snow-core dielectric properties to changes in density and to the travel times of reflecting horizons in the GPR section, and correlate some of these reflecting horizons with previous summer surfaces. We conclude that GPR can be used as a complementary tool in mass-balance measurements, giving a wide areal survey of winter accumulation and net balance for preceding years. However, proper calibration is essential for identifying specific surfaces in the radar data.


2019 ◽  
Vol 11 (5) ◽  
pp. 530 ◽  
Author(s):  
Bin Hu ◽  
Deli Wang ◽  
Ling Zhang ◽  
Zhaofa Zeng

Structural analysis of lunar regolith not only provides important information about lunar geology but also provides a reference for future lunar sample return missions. The Lunar Penetrating Radar (LPR) onboard China’s Chang’E-3 (CE-3) provides a unique opportunity for mapping the subsurface structure and the near-surface stratigraphic structure of the regolith. The problem of rock positioning and regolith-basement interface highlighting is meaningful. In this paper, we propose an adaptive rock extraction method based on local similarity constraints to achieve the rock location and quantitative analysis for regolith. Firstly, a processing pipeline is designed to image the LPR CH-2 A and B data. Secondly, we adopt an f-x EMD (empirical mode decomposition)-based dip filter to extract low-wavenumber components in the two data. Then, we calculate the local similarity spectrum between the filtered CH-2 A and B. After a soft threshold function, we pick the local maximums in the spectrum as the location of each rock. Finally, according to the extracted result, on the one hand, the depth of regolith is obtained, and on the other hand, the distribution information of the rocks in regolith, which changes with the path and the depth, is also revealed.


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