Boundary conditions significantly influence the near-field dynamics of bubbles. This study employs numerical simulations to investigate coupling characteristics high-pressure bubbles near solid boundaries and moving spherical boundaries. It focuses on effects sinking velocity sphere initial bubble–boundary distance bubble evolution loading characteristics. The results indicate that an increase in sphere's or a decrease leads tearing during collapse process. generates high-speed water jets...

This study reports the results of full-polarimetric Mars Rover Penetrating Radar (RoPeR) data acquired by China’s Tianwen-1 mission. A double-layered regolith structure within a depth 3 m is revealed which are different in scattering features, structure, and maturity. Five types dense rocks identified at surface subsurface. Three these residual materials native craters. Besides, on Martian isolated boulders delivered adjacent impacting or windblown events. The first stratum have...

The Chinese Chang’E-4 mission for moon exploration has been successfully completed. probe achieved the first-ever soft landing on floor of Von Kármán crater (177.59°E, 45.46°S) South Pole-Aitken (SPA) basin January 3, 2019. Yutu-2 rover is mounted with several scientific instruments including a lunar penetrating radar (LPR), which an effective instrument to detect subsurface structure. During interpretation LPR data, velocity electromagnetic waves vital parameter necessary stratigraphic...

As one of the main payloads mounted on Yutu-2 rover Chang’E-4 probe, lunar penetrating radar (LPR) aims to map subsurface structure in Von Kármán crater. The field LPR data are generally masked by clutters and noises large quantities. To solve noise interference, dozens filtering methods have been applied data. However, these their limitations, so suppression is still a tough issue worth studying. In this article, denoising convolutional neural network (CNN) framework weak signal extraction...

For water dynamics investigation in unsaturated (vadose) zones, ground penetrating radar is a popular hydro-geophysical method because it non-invasive for soil, has high resolution and the results have direct link with content. Soil content soil hydraulic properties are two key factors describing vadose zones. There been tremendous progress estimation radar. The purpose of this paper to provide an overview application studies. This first summarizes various methods determination including...

The full-polarimetric ground-penetrating radar (FP-GPR) can obtain the polarimetric attributes of targets and achieve more accurate identification compared with traditional GPRs. However, in most cases, signals collected by GPRs are not only from but also ground surface. According to classical Fresnel formulas, polarized directions waves will change after transmissions due difference transmission coefficients between horizontally vertically waves. This effect, called induced field rotation...

Full-polarimetric ground penetrating radar (FP-GPR) can measure the ability of an object to change polarization electromagnetic waves. Compared traditional GPR, it has a stronger capability identify underground objects. In recent years, series decomposition methods have been applied FP-GPR data processing obtain polarimetric attributes and enhance targets identification. Different characterize different features target but there is still no effective way integrate these take their respective...

Abstract This paper provides analyses to quantify the maturity of regolith within 24 m depth using a novel polarimetric attributes analysis lunar penetrating radar (LPR) data. The results demonstrate that LPR signals were mainly from subsurface rock fragments different sizes and rarely strata interfaces. averages ranges maturities for near‐surface (0–2 m), fine‐grained (2–12 coarse‐grained ejecta (12–24 m) are 68.98% (0%–99.82%), 82.61% (41.52%–96.56%), 72.33% (5.91%–96.66%), respectively....

Buried craters within tens of meters lunar regolith are rarely studied but significant for understanding the evolution surface processes on Moon. Here, we first report evidence an intact buried crater layered strata at Chang'E-4 (CE-4) landing site revealed by penetrating radar (LPR). The time–frequency comparative analysis method based variational mode decomposition (VMD) and rock quantitative local unit correlation (LUC) proposed applied to processing LPR data 15 days. results presented...

Fractures with fluid flow can lead to the damage of rock carving relics. During detection fractures, millimeter-scale fractures are usually difficult determine due their small apertures. Considering rapid variation water content in fracture seepage zone anisotropy, this article proposes a new methodology detect these using time-lapse full-polarimetric ground penetrating radar (FP-GPR) scheme and an anisotropy analysis method. The FP-GPR monitor infiltration rock, Freeman decomposition,...

A full-polarimetric ground penetrating radar (FP-GPR) uses an antenna array to detect subsurface anomalies. Compared the traditional GPR, FP-GPR can obtain more abundant information about subsurface. However, in field measurements, arrival time of received electromagnetic (EM) waves from different channels cannot be strictly aligned due limitations human operation errors and craftsmanship equipment. Small misalignments between radargrams acquired lead erroneous identification results classic...

China's first Mars probe Tianwen-1 has successfully landed on the southern Utopia Planitia of May 15, 2021. The Zhurong rover is equipped with a full-polarimetric Rover Penetrating Radar (FP-RoPeR) system, aiming to map subsurface fine structure and find potential underground water ice. However, different from previous ice detection orbital radar, FP-RoPeR signals will be affected by induced field rotation (IFR) if electromagnetic (EM) waves propagate through rough interfaces. Therefore, in...

China’s Tianwen-1 probe carrying the Zhurong rover has successfully landed on southern Utopia Planitia of Mars. The is first equipped with a full-polarimetric Mars Rover Penetrating Radar (FP-RoPeR) system, aiming to map fine structure and potential water-ice distribution Martian regolith. However, ground experiment earth indicates that RoPeR data severely affected by noises, clutters, signal misalignment. More importantly, an imbalance between from two cross-polarized channels observed...

Subsurface target classification of GPR is a hot topic geophysical field which aimed to classify different kinds targets based on their attributes, such as polarimetric attributes and geometrical features, although the existing methods can targets, but they are not efficient intelligent enough, especially in dealing with data large amounts. Support Vector Machine method Learning used samples attributes. We combine Machine(SVM) H-Alpha Decomposition for subsurface GPR. use H α parameters SVM...

The subsurface target classification of ground penetrating radar (GPR) is a popular topic in the field geophysics. Among existing methods, geometrical features and polarimetric attributes targets are primarily used. As contain more information targets, decomposition such as H-Alpha decomposition, have been developed for GPR recent years. However, template used preset depending on experience synthetic aperture (SAR); therefore, it may not be suitable GPR. Moreover, many methods require...

Ultrathick continuous slab casting is a growing technology, especially in developing countries due to the vast market demand of thick rolled plate. The structure submerged entry nozzle regarded as crucial factor determine flow related phenomena mould. This article conducts 0·55 scale water model and three-dimensional numerical investigate influences on behaviour, temperature field solidified shell distribution 420 mm ultrathick Physical finite volume methods with K–ϵ turbulence simulations...

The polarimetric response of full-polarimetric ground penetrating radar (FP-GPR) from anisotropic media is a pressing issue to be investigated. It can improve the detection accuracy targets in and also provide effective ways detect targets. In this paper, we focus on FP-GPR signals uniaxial bi-anisotropic media, i.e. complete case that both permittivity conductivity background are anisotropic. Based propagation characteristics electromagnetic waves transmission coefficients surface construct...

Full waveform inversion (FWI) of ground penetrating radar (GPR) is a promising imaging tool for the detailed characterization underground targets. In this study, on-ground GPR FWI used to construct permittivity and conductivity variations targets simultaneously. We applied memoryless quasi-Newton (MLQN) method solve inverse problem GPR. MLQN can attain acceptable results with low computational cost small memory storage requirements. Numerical test examined from multi-offset data show that...

The probe of China’s first Mars exploration mission, Tianwen-1, has been successfully launched. It will carry out scientific on the topography, soil characteristics, water ice, climate, ionosphere, and physical fields Mars. Different from other rovers landing moon Mars, Zhurong rover is equipped with a full polarimetric subsurface penetrating radar (FP-SPR) system for time. radar’s mission to depict shallow structure search possible ice. Therefore, in this paper, 3D realistic model...