scholarly journals A Compressive Sensing-Based Approach to Reconstructing Regolith Structure from Lunar Penetrating Radar Data at the Chang’E-3 Landing Site

2018 ◽  
Vol 10 (12) ◽  
pp. 1925 ◽  
Author(s):  
Kun Wang ◽  
Zhaofa Zeng ◽  
Ling Zhang ◽  
Shugao Xia ◽  
Jing Li
Keyword(s):  
Fourier Series ◽  
Compressive Sensing ◽  
Time Delays ◽  
Lunar Regolith ◽  
Landing Site ◽  
Radar Data ◽  
Lunar Rover ◽  
Signal Parameters ◽  
Lunar Environment ◽  
Scientific Systems

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.

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 ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Lunar Regolith ◽  
Landing Site ◽  
Radar Data

scholarly journals Volcanic history of the Imbrium basin: A close-up view from the lunar rover Yutu

2015 ◽  
Vol 112 (17) ◽  
pp. 5342-5347 ◽  
Author(s):  
Jinhai Zhang ◽  
Wei Yang ◽  
Sen Hu ◽  
Yangting Lin ◽  
Guangyou Fang ◽  
...  
Keyword(s):  
Lunar Regolith ◽  
Landing Site ◽  
Lunar Soil ◽  
Lunar Rover ◽  
Surface Exploration ◽  
Mantle Reservoir ◽  
History Of ◽  
Radar Measurements ◽  
Residual Melt

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.

Lunar regolith and substructure at Chang’E-5 landing site in the northern Oceanus Procellarum

2021 ◽  
Author(s):  
Hanjie Song ◽  
Hui Sun ◽  
Gang Yu ◽  
Yang Liu ◽  
Juan Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Lunar Regolith ◽  
Landing Site ◽  
Radar Data ◽  
Detection Methods ◽  
Force Analysis ◽  
Ridge Detection ◽  
Processing Procedure ◽  
Geological Context

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.

scholarly journals Parameter Estimation of Lunar Regolith from Lunar Penetrating Radar Data

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2907 ◽  
Author(s):  
Ling Zhang ◽  
Zhaofa Zeng ◽  
Jing Li ◽  
Ling Huang ◽  
Zhijun Huo ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Parameter Estimation ◽  
Lunar Regolith ◽  
Relative Dielectric Constant ◽  
Landing Site ◽  
Radar Data ◽  
Titanium Content ◽  
Complex Model ◽  
Electrical Parameters ◽  
Near Surface

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.

scholarly journals Rock Location and Property Analysis of Lunar Regolith at Chang’E-4 Landing Site Based on Local Correlation and Semblance Analysis

2020 ◽  
Vol 13 (1) ◽  
pp. 48
Author(s):  
Hanjie Song ◽  
Chao Li ◽  
Jinhai Zhang ◽  
Xing Wu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Lunar Regolith ◽  
Landing Site ◽  
Rock Properties ◽  
The Moon ◽  
Local Correlation ◽  
Near Surface ◽  
Property Analysis ◽  
Stratigraphic Division ◽  
Formation And Evolution

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.

Thermal modeling of the lunar regolith at the Chang'E‐4 landing site

2021 ◽  
Author(s):  
Honglei Lin ◽  
Shuai Li ◽  
Yangting Lin ◽  
Yang Liu ◽  
Yong Wei ◽  
...  
Keyword(s):  
Thermal Modeling ◽  
Lunar Regolith ◽  
Landing Site

Control of Drilling and Coring Device Based on Online Identification

2013 ◽  
Author(s):  
Qiquan Quan ◽  
S. Li ◽  
S. Jiang ◽  
X. Hou ◽  
Z. Deng
Keyword(s):  
Object Recognition ◽  
Lunar Regolith ◽  
Lunar Soil ◽  
Recognition System ◽  
Current Level ◽  
Support Vector ◽  
Drilling Process ◽  
Operating Modes ◽  
Online Identification ◽  
Lunar Environment

This paper presents a drilling and coring device for the lunar exploration, which is possibly utilized to acquire the lunar regolith with a certain depth. The drilling device is composed of three components: rotary unit, percussive unit and penetrating unit. The rotary-percussion drill can work in two different operating modes: rotary mode and rotary-percussive mode, depending on the properties of cut object. In the relatively loose regolith, rotation and penetration can make the drill work in a well state. However, once rock is encountered in the drilling process, besides rotation and penetration, percussion must be launched to reduce the drilling power and the required penetrating force. Due to the indetermination of the lunar environment, it is not easy to control the coring drill to adapt to the encountered conditions. To obtain a high coring ratio with relatively low power, an intelligent drilling strategy is inevitably proposed to accomplish the drilling process control. Considering the lunar soil simulant should cover the possible composition of real lunar soil, simulant are classified into several levels based on the generalized drillability. For each level of drillability of lunar soil simulant, experiments are conducted to get the characteristics in frequency-domain of rotary torque output. The sampled characteristics of rotary torque output are utilized to train the object-recognition system based on Support Vector Machine (SVM). Information in all the levels of drillability of lunar soil simulant is stored in the object-recognition system as an expert system. To understand the properties of the drilling object, rotary torque is selected to identify the level of drillability of simulant in drilling process. Subsequently, once the level is obtained, drilling strategy is adjusted to adapt to the current level correspondingly in real time. Experiments are conducted to verify the intelligent drilling strategy successfully.

Training Periodic Sequences Using Fourier Series Error Criterion

1993 ◽  
Vol 5 (1) ◽  
pp. 115-131 ◽  
Author(s):  
James A. Kottas
Keyword(s):  
Fourier Series ◽  
Time Delays ◽  
Spectral Energy ◽  
Fourier Space ◽  
Training Algorithm ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Periodic Sequences ◽  
Periodic Input ◽  
Low Pass

Training a network to learn a set of periodic input/output sequences effectively makes the network learn a mapping between amplitudes and phases in Fourier space. The spectral backpropagation (SBP) training algorithm is a different way of doing this task. It measures the Fourier series components of the output error sequences and minimizes the total spectral energy as an adaptation criterion. This approach can train not only the weights but also time delays associated with the interconnects. Furthermore, the cells can have finite bandwidth via a first-order low-pass filter. Having adaptable time delays gives the SBP algorithm a powerful way to control the phase characteristics of the network.

Lunar regolith and substructure at Chang’E-4 landing site in South Pole–Aitken basin

2020 ◽  
Author(s):  
Jinhai Zhang ◽  
Bin Zhou ◽  
Yangting Lin ◽  
Meng-Hua Zhu ◽  
Hanjie Song ◽  
...  
Keyword(s):  
Lunar Regolith ◽  
Landing Site ◽  
South Pole

Mechanics Analysis and the Simulation for Lunar Rover in Virtual Lunar Environment

2013 ◽  
Vol 12 (20) ◽  
pp. 5707-5712
Author(s):  
Zhao Yi-Bing ◽  
Li Lin-Hui ◽  
Lv Hong Sen ◽  
Guo Lie ◽  
Pan Chi
Keyword(s):  
Lunar Rover ◽  
Mechanics Analysis ◽  
Lunar Environment
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