Icarus最新文献_第4页

On the stability limits for moons orbiting planets: A numerical investigation 围绕行星运行的卫星的稳定性极限：数值研究

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-26 DOI: 10.1016/j.icarus.2025.116924

G.O. Barbosa , T. Santana , O.C. Winter

We investigate the long-term dynamical stability of moons orbiting planets by performing high-resolution

N

-body simulations across five planet-to-star mass ratios (

μ = 1 0^{- 1}

to

1 0^{- 5}

). Moons are modeled as massless test particles and their orbits are initialized at pericenter, where stellar perturbations are minimized. This setup yields upper-envelope estimates of the outermost stable semimajor axis (

a_{E}

) under optimally phased initial conditions, which we systematically map as a function of eccentricity. We derive empirical fits for

a_{E} (e)

in each

μ

regime and observe that the stable region contracts with increasing eccentricity and decreasing planetary mass. For larger values of

μ

, we identify a detached island of stability at intermediate eccentricities (

0.2 ≲ e ≲ 0.7

), which we show to be associated with the evection resonance; additional integrations confirm libration of the resonant angle. We examine the sensitivity of

a_{E}

to the initial satellite–star mean-anomaly offset (

Δ M

) and find that orbital phase can modulate the critical stability threshold by

≲ 10 %

. Our updated stability criteria therefore consist of: (i) new empirical fits for the critical semimajor axis as a function of eccentricity, (ii) its systematic dependence on the planet-to-star mass ratio, and (iii) the role of the evection resonance and orbital phase in extending stability beyond classical limits. These results provide a refined framework for assessing exomoon survivability across diverse planetary systems. The empirical relations presented in this work can be directly employed to constrain the parameter space in observational searches for exomoons.

我们通过在五种行星-恒星质量比（μ=10−1至10−5）下进行高分辨率n体模拟，研究了围绕行星运行的卫星的长期动力学稳定性。卫星被建模为无质量的测试粒子，它们的轨道在中心初始化，那里恒星的扰动最小。这种设置在最佳相位初始条件下产生最外层稳定半长轴（aE）的上包络估计，我们将其系统地映射为偏心的函数。我们对aE(e)在每个μ区进行了经验拟合，并观察到稳定区随偏心距的增大和行星质量的减小而收缩。对于较大的μ值，我们在中间偏心率处（0.2≤e≤0.7）发现了一个独立的稳定岛，我们认为这与喷射共振有关；附加积分确认谐振角的振动。我们考察了声发射对初始星-星平均异常偏移量（ΔM）的敏感性，发现轨道相位可以将临界稳定性阈值调制约10%。因此，我们更新的稳定性标准包括：(i)临界半长轴作为偏心率函数的新经验拟合，（ii）它对行星与恒星质量比的系统依赖，以及（iii）在将稳定性扩展到经典极限之外的过程中，抛射共振和轨道相位的作用。这些结果为评估不同行星系统的系外卫星生存能力提供了一个完善的框架。本文提出的经验关系可直接用于约束系外卫星观测搜索中的参数空间。

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引用次数: 0

Far ultraviolet carbon emissions in the Mars aurora: Brightness, intensity ratios and seasonal dependence 火星极光中的远紫外线碳排放：亮度、强度比和季节依赖性

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-24 DOI: 10.1016/j.icarus.2025.116919

J.C. Gérard , L. Soret , B. Hubert , R. Lillis , S. Jain , J. Deighan

Neutral carbon emissions have been observed in Far Ultraviolet spectra (FUV) of the Martian aurora with the Emirates Mars Ultraviolet Spectrometer (EMUS) instrument on board the Emirates Mars Mission (EMM). Oxygen emissions at 130.4 and 135.6 nm have been used to map the auroral morphology and its dependence on solar wind parameters. The CI emissions at 156.1 and 165.7 nm are excited by collisions between energetic electrons and CO₂, CO and C. We present Monte Carlo simulations of the altitude distributions of both features showing that electron collisions with ambient CO₂ molecules are the dominant source, followed by collisions on CO, while direct impact on C atoms is several orders of magnitude smaller. Since the C atom fragments resulting from dissociation are produced with a speed exceeding by far the thermal velocity, the optical depth is negligible. Consequently, the 156.1 and 165.7 nm photons are not self-absorbed, and the calculation of the emission rates does not require consideration of radiative transfer, unlike the OI 130.4 nm triplet. We present calculations of the efficiency of the carbon emissions for a range of incident auroral electrons energies. We illustrate the energy dependence of the intensity ratios between the oxygen 130.4 and 135.6 nm and the carbon 165.7 nm emissions. These ratios may be used to remotely characterize the spatial distribution of the incident electron energies in spectral FUV maps of the aurora.

利用阿联酋火星任务（EMM）上的阿联酋火星紫外光谱仪（EMUS）仪器，在火星极光的远紫外光谱（FUV）中观察到中性碳排放。在130.4和135.6 nm处的氧发射被用来绘制极光形态及其对太阳风参数的依赖。156.1和165.7 nm处的CI辐射是由高能电子与CO2、CO和C碰撞激发的。我们对这两个特征的高度分布进行了蒙特卡罗模拟，结果表明电子与周围CO2分子碰撞是主要来源，其次是与CO碰撞，而直接撞击C原子的程度要小几个数量级。由于解离产生的C原子碎片的速度远远超过热速度，因此光学深度可以忽略不计。因此，156.1和165.7 nm光子不是自吸收的，发射率的计算不需要考虑辐射传输，这与OI 130.4 nm三重态不同。我们给出了在一定范围内入射极光电子能量的碳排放效率的计算。我们说明了130.4和135.6 nm的氧和165.7 nm的碳发射的强度比之间的能量依赖关系。这些比值可以用来远程表征极光光谱FUV图中入射电子能量的空间分布。

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引用次数: 0

A perspective on the luminous efficiency approach for meteoroid mass estimation 流星体质量估算的发光效率方法研究进展

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-22 DOI: 10.1016/j.icarus.2025.116922

Christopher O. Johnston , Alireza Mazaheri , Eric C. Stern

A perspective on the luminous efficiency approach for determining the pre-atmospheric mass of a meteoroid from a measured light-curve is presented for meteors in the continuum flow regime. This perspective interprets the mass-loss rate evaluated from the luminous efficiency approach as a solution to the meteoroid surface energy balance, with the measured light-curve serving as a proxy for the radiative heating to the meteoroid surface. This differs from the standard interpretation that equates the radiation from the light-curve to a change in the kinetic energy of the meteor. Mathematically, the developed perspective is identical to the standard luminous efficiency approach, except that the deceleration term is shown to be extraneous. This perspective provides a clear relationship between the measured light-curve and the mass loss of a meteor, which is based on the observation that the radiative heating that drives the mass loss (through the surface energy balance) also provides the radiation for the light-curve. Furthermore, this perspective provides a simple mathematical framework for interpreting the impact of fragmentation on the luminous efficiency. This framework shows that the luminous efficiency of a fragmented meteoroid is a weighted sum of the luminous efficiency from the various fragments, which may each be assessed based on single-body simulations. To generate these single-body simulations, state-of-the-art flowfield and radiation simulations are performed for meteoroid diameters ranging from 0.02 to 100 m, velocities ranging from 12 to 24 km/s, and altitudes ranging from 20 to 50 km. The luminous efficiency values resulting from these simulations are distilled into a correlation and applied to trajectories resulting from the fragment cloud method. This allows the integral luminous efficiency to be computed using the developed luminous efficiency model and defined fragmentation framework. Both the silicon and visible passbands are considered. For the silicon passband, the computed integral luminous efficiency values track closely with the experimentally derived integral luminous efficiency model developed by Brown et al. (2002). This represents the first theoretical derivation of the integral luminous efficiency approach based on fully coupled radiation and ablation simulations with viscous effects, which also captures the impact of individual meteoroids that are combined using the developed fragmentation framework.

本文提出了用光曲线测量流星体大气前质量的发光效率方法在连续流状态下的应用。这种观点解释了从发光效率方法评估的质量损失率作为流星体表面能量平衡的解决方案，测量的光曲线作为流星体表面辐射加热的代理。这与将光曲线的辐射等同于流星动能变化的标准解释不同。在数学上，所开发的视角与标准的发光效率方法是相同的，只是减速项被证明是无关的。这种观点提供了测量的光曲线和流星质量损失之间的清晰关系，这是基于观测到的驱动质量损失的辐射加热（通过表面能量平衡）也为光曲线提供了辐射。此外，这一视角为解释碎片化对发光效率的影响提供了一个简单的数学框架。该框架表明，碎片流星体的发光效率是来自不同碎片的发光效率的加权和，每个碎片都可以基于单一物体模拟来评估。为了生成这些单一物体的模拟，最先进的流场和辐射模拟进行了流星体直径范围从0.02到100米，速度范围从12到24公里/秒，高度范围从20到50公里。从这些模拟得到的发光效率值被提炼成一种相关性，并应用于由碎片云方法得到的轨迹。这允许使用开发的发光效率模型和定义的碎片框架来计算积分发光效率。硅通带和可见光通带都被考虑。对于硅通带，计算的积分发光效率值与Brown等人（2002）开发的实验推导的积分发光效率模型密切相关。这代表了基于具有粘性效应的完全耦合辐射和烧蚀模拟的积分发光效率方法的第一个理论推导，该方法还捕获了使用已开发的碎片框架组合的单个流星体的影响。

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引用次数: 0

Identification and characterization of the topside bulge of the Venusian ionosphere 金星电离层顶部凸起的识别和表征

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-22 DOI: 10.1016/j.icarus.2025.116920

Satyandra M. Sharma , Varun Sheel , Martin Pätzold

Venus, in the absence of an intrinsic magnetic field, undergoes a direct interaction between its ionosphere and the solar wind. Previous missions, including Mariner, Venera, and the Pioneer Venus Orbiter (PVO), reported a recurring localized increase in electron density, often termed a ”bulge,” at altitudes between 160 and 200 km. This study investigates this topside bulge using over 200 dayside electron density profiles derived from the Venus Radio Science experiment (VeRa) onboard the Venus Express (VEX). We employ an automated, gradient-based classification algorithm to provide a quantitative and reproducible method for identifying and categorizing the bulge morphology into three types. Type 1 profiles exhibit a distinct secondary peak above the main V2 layer. Type 2 profiles display a shoulder-like feature near the bulge altitude. Type 3 bulges are not visually apparent but can be identified through residuals obtained after subtracting a Chapman layer fit to the V2 peak. The bulge is detected in over 80% of the analyzed profiles, with a higher occurrence during periods of low solar activity and at lower solar zenith angles (

S Z A s

). Type 1 morphologies are only observed at low latitudes (within

\pm

40°N). The peak altitude of the bulge negatively correlates with

S Z A

, suggesting that thermospheric cooling toward the terminator significantly influences the bulge altitude. The occurrence patterns and morphological characteristics indicate that the bulge is likely influenced by external drivers, such as solar wind interaction, rather than being solely a result of local photochemical processes.

金星在没有固有磁场的情况下，经历了电离层和太阳风之间的直接相互作用。以前的任务，包括水手号、金星号和先锋金星轨道飞行器（PVO），都报告了在160到200公里高度之间反复出现的局部电子密度增加，通常被称为“凸起”。本研究利用金星快车（VEX）上的金星无线电科学实验（VeRa）获得的200多个日侧电子密度分布图来研究上部凸起。我们采用了一种自动的、基于梯度的分类算法，提供了一种定量的、可重复的方法，将凸起形态识别和分类为三种类型。1型剖面在主V2层上方有一个明显的次级峰。2型轮廓在凸起高度附近显示类似肩部的特征。3型凸起在视觉上不明显，但可以通过减去与V2峰拟合的Chapman层后得到的残差来识别。在超过80%的分析剖面中都检测到凸起，在太阳活动低和太阳天顶角（SZAs）较低的时期发生的频率较高。1型形态仅在低纬度地区（±40°N以内）观察到。凸起的峰值高度与SZA呈负相关，表明热层向终点冷却对凸起高度有显著影响。其发生模式和形态特征表明，凸起可能受到外部驱动因素的影响，如太阳风相互作用，而不仅仅是局部光化学过程的结果。

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引用次数: 0

Lunar surface modification revealed by in-situ photometric observations from Chang'E-6 嫦娥六号原位光度观测揭示的月球表面变化

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-20 DOI: 10.1016/j.icarus.2025.116921

Tianyi Xu , Wei Cai , Yunzhao Wu , Xiaoping Zhang , Yanyan Xu , Meizhu Wang , Zhiping He , Cunhui Li , Weidong Qiao , Jinyou Tao , Jianfeng Yang

The Chang'E-6 mission landing on the far side of the Moon, conducted in-situ measurements of the lunar regolith using a Panoramic Camera and Lunar Mineralogical Spectrometer. The rocket exhaust created distinct bright zones around the landing site, categorized as focused blast zones and diffuse blast zones. This study analyzes the photometric properties across native regolith, blast zones, and underfoot regions using the Hapke model, integrating data from both the panoramic camera and the spectrometer. Results show that backscattering increases with proximity to the lander. The observed brightening within the blast zone is primarily attributed to the removal of fine particles and the exposure of immature regolith. Regions immediately adjacent to the lander exhibit lower albedo, forward scattering behavior, higher spectral slopes, and a shallower 1 μm absorption band, suggesting the presence of glassy materials and an increased abundance of agglutinates.

嫦娥六号在月球背面着陆，使用全景相机和月球矿物光谱仪对月球风化层进行了现场测量。火箭排出的气体在着陆点周围形成了明显的明亮区域，分为集中爆炸区和扩散爆炸区。本研究利用Hapke模型，综合了全景相机和光谱仪的数据，分析了原生风化层、爆炸区和脚下区域的光度特性。结果表明，后向散射随着陆器的靠近而增大。在爆炸区域内观测到的变亮主要归因于细颗粒的去除和未成熟风化层的暴露。与着陆器相邻的区域表现出较低的反照率、正向散射行为、较高的光谱斜率和较浅的1 μm吸收带，表明存在玻璃状物质和增加的凝集物丰度。

引用次数: 0

Jupiter’s middle magnetosphere as observed by Juno JADE-I 朱诺jade - 1观测到的木星中间磁层

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-19 DOI: 10.1016/j.icarus.2025.116918

R.J. Wilson

This paper investigates ion plasma properties in the jovian middle magnetosphere utilizing two Juno JADE-I datasets, and two different techniques. Proton properties are found using the SPECIES proton dataset and numerical moments. Simultaneous forward modeling of the TOF and SPECIES data is used to extract plasma parameters from 4 heavy ion species of sulfur and oxygen ions (S

^{+}

, S

^{+ + +}

, O

^{+ +}

and a

m / q = 16

a m u / q

ion species representing both S

^{+ +}

and O

^{+}

). These four ion species share a bulk velocity but have independent density and isotropic temperatures. The proton moments provide an isotropic temperature, and velocities that are consistent with that of the heavies. Data from Juno’s Prime Mission are analyzed, showing that most data is sub-corotational, with occasional intervals of super-corotation or anti-corotation flows. The relative abundances of the five ions are investigated, and while the

m / q = 16

a m u / q

ion species dominates throughout all radial distances, protons density can be the second largest abundance, and equivalent to the minor heavy ions at larger distances, suggesting their influence had been previously underestimated.

本文利用两个朱诺jade - 1数据集和两种不同的技术研究了木星中磁层的离子等离子体特性。利用SPECIES质子数据集和数值矩来发现质子的性质。利用TOF和SPECIES数据同步正拟，提取硫离子和氧离子（S+、s++ +、o++ +和m/q=16 amu/q分别代表S++和O+）的4种重离子的等离子体参数。这四种离子具有相同的体速度，但具有独立的密度和各向同性温度。质子矩提供了各向同性的温度，并且速度与重粒子一致。对朱诺号主要任务的数据进行分析后发现，大多数数据都是次自转的，偶尔会出现超自转或反自转的现象。研究了这五种离子的相对丰度，虽然m/q=16 amu/q离子在所有径向距离中占主导地位，但质子密度可能是第二大丰度，相当于较大距离的次要重离子，这表明它们的影响以前被低估了。

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引用次数: 0

Not enough H2O2 to warm early Mars 没有足够的H2O2来温暖早期的火星

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-19 DOI: 10.1016/j.icarus.2025.116914

Maxime Maurice , François Forget , Franck Lefèvre , Aurélien Stolzenbach , A. Yassin Jaziri , Ashwin S. Braude , Martin Turbet , Ehouarn Millour , Yangcheng Luo

There exists strong geomorphological, sedimentary and mineralogical evidence that Mars had an active surface hydrological cycle during the Noachian period, about 3.8 Gyr ago (Ga). However, how surface temperatures compatible with perennial liquid water could be sustained in spite of a Sun that only had 75% of its present-day brightness has remained elusive, leading to the faint young Sun paradox for Mars. Recently, the greenhouse effect of hydrogen peroxide (H

_{2}

O

_{2}

) has been proposed as a solution by Ito et al. (2020). Radiative transfer models have shown that a few ppmv of H

_{2}

O

_{2}

in a 1 or 2 bar CO

_{2}

atmosphere could solve the faint young Sun paradox on early Mars. In a warm and wet CO

_{2}

atmosphere, H

_{2}

O

_{2}

is produced by photochemistry and contributes to the stability of the CO

_{2}

atmosphere along with the HO

_{x}

(H, OH and HO

_{2}

) catalytic cycles. Nevertheless, a thorough assessment of the viability of such a high H

_{2}

O

_{2}

abundance is still lacking. Using 1D and 3D climate models coupled with a C–H–O photochemistry solver, we show that in the most favorable case for H

_{2}

O

_{2}

to build up, its steady-state abundance is several orders of magnitude short from its required abundance of

\sim 1

ppmv to have a significant radiative effect. Furthermore, we also show that a transient warming episode associated with massive H

_{2}

O

_{2}

release cannot exceed 10 Martian years. We therefore rule out H

_{2}

O

_{2}

as a warming agent for early Mars.

有强有力的地形学、沉积学和矿物学证据表明，火星在3.8 Gyr ago (Ga) Noachian时期有一个活跃的地表水循环。然而，在太阳亮度只有现在的75%的情况下，火星表面的温度如何能与常年存在的液态水保持一致，这仍然是一个难以捉摸的问题，这导致了火星年轻太阳微弱的悖论。最近，Ito等人（2020）提出了过氧化氢（H2O2）的温室效应作为解决方案。辐射传输模型表明，在1或2巴的二氧化碳大气中，几ppmv的H2O2可以解决早期火星上微弱的年轻太阳悖论。在温暖潮湿的CO2大气中，H2O2通过光化学反应产生，并与HOx （H， OH和HO2）催化循环一起有助于CO2大气的稳定性。然而，对如此高的H2O2丰度的生存能力的全面评估仍然缺乏。利用1D和3D气候模型加上C-H-O光化学解算器，我们发现，在H2O2最有利的情况下，其稳态丰度比产生显著辐射效应所需的丰度（~ 1 ppmv）短几个数量级。此外，我们还表明，与大量H2O2释放相关的短暂变暖事件不会超过10个火星年。因此，我们排除了H2O2作为早期火星变暖剂的可能性。

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引用次数: 0

The two-dimensional structure of circumplanetary disks and their radiative signatures 绕行星盘的二维结构及其辐射特征

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-16 DOI: 10.1016/j.icarus.2025.116913

Aster G. Taylor , Fred C. Adams , Nuria Calvet

During their formative stages, giant planets are fed by infalling material sourced from the background circumstellar disk. Due to conservation of angular momentum, the incoming gas and dust collects into a circumplanetary disk that processes the material before it reaches the central planet itself. This work investigates the complex vertical structure of these circumplanetary disks and calculates their radiative signatures. A self-consistent numerical model of the temperature and density structure of the circumplanetary environment reveals that circumplanetary disks are thick and hot, with aspect ratios

H / R \sim 0.1 - 0.25

and temperatures approaching that of the central planet. The disk geometry has a significant impact on the radiative signatures, allowing future observations to determine critical system parameters. The resulting disks are gravitationally stable and viscosity is sufficient to drive the necessary disk accretion. However, sufficiently rapid mass accretion can trigger a thermal instability, which sets an upper limit on the mass accretion rate. This paper shows how the radiative signatures depend on the properties of the planetary system and discuss how the system parameters can be constrained by future observations.

在它们形成的阶段，巨行星是由来自背景星周盘的流入物质喂养的。由于角动量守恒，进入的气体和尘埃会聚集在一个环绕行星的圆盘上，在到达中心行星之前，这个圆盘会对这些物质进行处理。这项工作研究了这些绕行星盘的复杂垂直结构，并计算了它们的辐射特征。一个自洽的温度和密度结构的数值模型显示，环行星盘厚而热，纵横比为H/R ~ 0.1−0.25，温度接近中心行星的温度。圆盘的几何形状对辐射特征有重大影响，这使得未来的观测能够确定关键的系统参数。由此产生的盘在引力上是稳定的，并且粘度足以驱动必要的盘吸积。然而，足够快的质量吸积会引发热不稳定性，这为质量吸积速率设定了上限。本文展示了辐射特征如何依赖于行星系统的性质，并讨论了系统参数如何受到未来观测的约束。

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引用次数: 0

From lunar terrain to learned representations: A comparative study of crater extraction 从月球地形到学习表征：陨石坑提取的比较研究

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-13 DOI: 10.1016/j.icarus.2025.116909

Ersa Wei , Xiangmei Liu , Minxuan Gao , Feng Zhang , Pingping Lu , Yanan Dang , Jiahan Wang , Tao Wu , Jiaqi Chen

Lunar craters are crucial for understanding the Moon’s evolutionary history and mission planning. However, their vast quantity and extensive distribution make establishing a reliable database through manual counting extremely challenging. To improve crater extraction efficiency, this study proposes and evaluates optimized traditional morphological methods and novel deep learning models within the 60°S-60°N latitude range. For traditional methods, we developed a morphological feature extraction algorithm that integrates highlight-shadow region detection with edge features from multi-source data (DOM and DEM). Compared to single detection benchmarks, this fusion strategy significantly enhances performance, improving recall and precision by 13.42% and 28.91% respectively. In deep learning, we propose Bottleneck Residual U-Net (BRU-Net) and Spatial Attention Bottleneck Residual U-Net (SA-BRU-Net) based on the U-Net architecture. These models were trained on cropped and transformed lunar DEM data and combined with template matching algorithms. Their overall performance surpasses the baseline U-Net model. The study further demonstrates that model extraction effectiveness can be progressively improved through dataset optimization, network depth increase, and extended training duration. To enable fair quantitative evaluation of both technical approaches, the study designed comparative extraction experiments using the same DEM dataset. The SA-BRU-Net model successfully extracted 171,136 craters, while the traditional algorithm identified only 31,760 from the same data source. This advantage was particularly evident in detecting small craters with degraded morphology and blurred features (accounting for 80.20% of total extractions), confirming the generational advantage of deep learning models in pattern recognition and generalization capability. This result identified approximately seven times more craters than the combined Head and Povilaitis catalogs, potentially supplementing existing manual crater inventories.

月球环形山对于了解月球的演化历史和任务规划至关重要。然而，它们数量庞大，分布广泛，通过人工计数建立可靠的数据库极具挑战性。为了提高陨石坑的提取效率，本研究提出并评估了在60°S-60°N纬度范围内优化的传统形态学方法和新的深度学习模型。对于传统方法，我们开发了一种将高光阴影区域检测与多源数据（DOM和DEM）的边缘特征相结合的形态学特征提取算法。与单一检测基准相比，该融合策略显著提高了性能，召回率和准确率分别提高了13.42%和28.91%。在深度学习中，我们提出了基于U-Net架构的瓶颈残差U-Net （BRU-Net）和空间注意力瓶颈残差U-Net （SA-BRU-Net）。这些模型在裁剪和转换后的月球DEM数据上进行训练，并与模板匹配算法相结合。它们的整体性能优于基准U-Net模型。研究进一步表明，通过数据集优化、增加网络深度和延长训练时间，可以逐步提高模型提取的有效性。为了对这两种技术方法进行公平的定量评估，该研究使用相同的DEM数据集设计了比较提取实验。SA-BRU-Net模型成功提取了171,136个陨石坑，而传统算法从相同的数据源中仅识别了31,760个陨石坑。这种优势在检测形态退化和特征模糊的小陨石坑（占总提取量的80.20%）时尤为明显，证实了深度学习模型在模式识别和泛化能力方面的世代优势。这一结果确定的陨石坑数量大约是Head和Povilaitis合并目录的7倍，有可能补充现有的手动陨石坑清单。

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引用次数: 0

Revisiting the crater-based age of Cerealia Facula: High-resolution XMO7 data, measurement uncertainties, and chronological frameworks 重新审视以陨石坑为基础的斑谷年龄：高分辨率XMO7数据、测量不确定性和时间框架

IF 3 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2025-12-13 DOI: 10.1016/j.icarus.2025.116908

Alicia Neesemann , Stephan van Gasselt , Christian Riedel

This study examines the effects of crater-size frequency data collections and modeling parameters to better understand their influence on model ages for Cerealia Facula on Ceres. Key factors in this investigation include (a) analyst-dependent data collection, (b) slope discrepancies between measured distributions and modeled production functions, and (c) choice of chronology models. The foundational cartographic product for this work is a novel controlled high-resolution image mosaic built from data of NASA’s Dawn Framing Camera in XMO7 orbit. Our study returns crater-based absolute model ages for Cerealia Facula using the Lunar-derived chronology model (4.23 ± 0.36 Ma) and the Asteroid-flux-derived chronology model (0.43 ± 0.04 to 39.53 ± 3.26 Ma). Results show that model ages derived from small-area measurements are highly sensitive to (1) data collection bias and variability, particularly for craters smaller than 50 m, (2) the chosen distribution diameter range for age modeling, and (3) the chronology model, which can shift ages by a factor of up to 10. For complex regions like Cerealia Facula, using larger craters across wider areas offers more robust results. This investigation highlights the importance of high-resolution datasets for improving CSFD reliability and emphasizes the need for consistency in data collection and model selection. To provide additional geological context, an IHS pan-sharpened RGB orthomosaic was generated from XMO7 clear-filter data combined with LAMO-based RGB data, covering both Cerealia Facula and Vinalia Faculae at a ground sample distance of 8.5 m. The corresponding mosaics have been uploaded at the Zenodo (https://zenodo.org/records/17615401) data repository and are permanently accessible.

本研究考察了陨石坑大小频率数据收集和建模参数的影响，以更好地了解它们对谷神星上谷状斑的模型年龄的影响。本研究的关键因素包括(a)依赖于分析人员的数据收集，(b)测量分布和建模生产函数之间的斜率差异，以及(c)时序模型的选择。这项工作的基础制图产品是一种新型的受控高分辨率图像拼接，该图像是由美国宇航局在XMO7轨道上的黎明分幅相机的数据构建的。我们的研究使用月球衍生的年代学模型（4.23±0.36 Ma）和小行星通量衍生的年代学模型（0.43±0.04至39.53±3.26 Ma）返回了基于陨石坑的谷草斑的绝对模型年龄。结果表明，小面积测量得出的模型年龄对以下因素高度敏感：(1)数据收集偏差和变异性，特别是小于50 m的陨石坑；(2)年龄建模选择的分布直径范围；(3)年代学模型，其年龄偏移可达10倍。对于像谷斑这样的复杂区域，在更大的区域使用更大的陨石坑可以提供更可靠的结果。本研究强调了高分辨率数据集对提高CSFD可靠性的重要性，并强调了数据收集和模型选择一致性的必要性。为了提供更多的地质背景，将XMO7透明滤波数据与基于lamo的RGB数据相结合，生成了IHS泛锐化RGB正射影图，覆盖了地面样品距离为8.5 m的ceralia Facula和Vinalia教员。相应的马赛克已经上传到Zenodo （https://zenodo.org/records/17615401）数据存储库，并且可以永久访问。

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