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71.
Brightness temperature is a main index to reflect the energy of microwave radiation of an object. Using lunar brightness temperature data, physical properties of lunar regolith, such as thickness, heat flow and dielectric permittivity, could be interpreted. There are two methods to study brightness temperature distribution of the moon: the first is used to measure lunar brightness temperature by radio observation or spaceborne microwave radiometers, and the second is used to simulate calculation by the physical model. On the basis of the measurements of lunar brightness temperature in the history, this study analyzed the main physical model of lunar brightness temperature, also including its theory and influence factors. The authors concluded that surface and subsurface temperatures of the moon, dielectric properties and layered structure of lunar regolith were the main factors affecting the global brightness temperature of the moon. These factors should be quantified in detail in the future research.  相似文献   
72.
月面环境与月壤特性研究的主要问题探讨   总被引:6,自引:0,他引:6  
月面环境与月壤特性是月球探测和月球科学研究的重要基础,对它们的研究一直在不断加深,本文对月球表面地形地貌、热环境以及月壤特性三个方面的研究现状进行了总结,初步分析了这三个方面研究目前存在的一些主要问题:(1)地形地貌对月球定量遥感的影响以及南极艾特肯(SPA)盆地等地貌单元的年代学划分和成因演化;(2)月面热辐射、月表物理温度和热流等月面热环境特征的进一步探测和全面分析,以及其对地球反照率变化的响应;(3)月壤形成演化过程及空间风化作用,月球极区氢富集机制和水冰探测,以及月球资源开发利用。  相似文献   
73.
Lunar landforms are the results of geological and geomorphic processes on the lunar surface. It is very important to identify the types of lunar landforms. Geomorphology is the scientific study of the origin and evolution of morphological landforms on planetary surfaces. Elevation and relief amplitude are the most commonly used geomorphic indices in geomorphological classification studies. Previous studies have determined the elevation classification criteria of the lunar surface. In this paper, we focus on the classification criteria of the topographic relief amplitude of the lunar surface. To estimate the optimal window for calculating the relief amplitude of the lunar surface, we use the mean change-point method based on LOLA (Lunar Orbiter Laser Altimeter) Digital Elevation Model (DEM) data and SLDEM2015 DEM data combining observations from LOLA and SELenological and Engineering Explorer Terrain Camera (SELENE TC). The classification criterion of the lunar surface relief amplitude is then determined according to the statistical analysis of basic lunar landforms. Taking the topographic relief amplitudes of 100 m, 200 m, 300 m, 700 m, 1500 m and 2500 m as thresholds, the lunar surface is divided into seven geomorphic types, including minor microrelief plains (< 100 m), minor microrelief platforms [100 m, 200 m), microrelief landforms [200 m, 300 m), small relief landforms [300 m, 700 m), medium relief landforms [700 m, 1500 m), large relief landforms [1500 m, 2500 m) and extremely large relief landforms (≥ 2500 m). The minor microrelief plains are mainly distributed in the maria and the basalt filled floors of craters and basins, while the minor microrelief platforms are mainly in the transition regions between the maria and highlands. The microrelief landforms are mainly located in regions with relatively high topography, such as wrinkle ridges and sinuous rilles in the mare. The small relief landforms are mainly scattered in the central peak and floor fractures of craters. The medium relief landforms are mainly distributed in the transition regions between crater floors and crater walls, between crater walls and crater rims, between basin floors and basin walls, and between basin walls and basin rims. Large and extremely large relief landforms are mainly found along crater walls and basin walls. The classification criteria determination for assessing lunar surface relief amplitude described in this paper can provide important references for the construction of digital lunar surface geomorphology classification schemes.  相似文献   
74.
嫦娥3号巡视探测器桅杆的展开机构、偏航机构和俯仰机构在转动过程中存在系统性的偏差,这些误差影响了巡视探测器导航定位、地形恢复和路径规划的精度.针对这一问题,文章提出了一种间接平差模型,通过真实数据试验证明该方法能够用于对嫦娥3号巡视探测器桅杆的转动角度误差进行检校,并且具有很高的精度和稳定性.  相似文献   
75.
半参数模型增强了模型的适应性,在测绘数据处理中得到越来越广泛的应用。采用半参数模型对传统的布尔莎七参数模型进行改进,利用公共点坐标数据进行分析计算,并讨论半参数模型中正则矩阵的选取对模型精度的影响。为传统大地坐标转换提供一种解决途径。  相似文献   
76.
以天山构造带区域为例,分别用精密水准和GNSS给出地壳形变垂直运动速率矢量图,对其差异及差异形成的原因进行深入分析和探讨,并基于优势互补原则,给出二者融合的形变图像。根据多年研究经验认为,该方法得到的垂直形变图在强震中长期预测中具有较为重要的应用价值。  相似文献   
77.
?????????????????????????ι??????????????????????????????γ?????е?4?η???,???????????????γ??????????4?η?????????????????Ч?????????е????????????????????  相似文献   
78.
Suitable lunar constellation coverage can be obtained by separating the satellites in inclinations and node angles. It is shown in the paper that a relevant saving of velocity variation ΔV can be achieved using weak stability boundary trajectories. The weakly stable dynamics of such transfers allows the separation of the satellites from the nominal orbit to the required orbit planes with a small amount of ΔV. This paper also shows that only one different set of orbital parameters at Moon can be reached with the same ΔV manoeuvre starting from a nominal trajectory and ending at a fixed periselenium altitude. In fact, such a feature is proved to be common to other simpler dynamical systems, such as the two- and three-body problems.  相似文献   
79.
80.
This paper is an attempt to bring unity in the study of the classical Kepler problem by combining, through simple vectorial and quaternionic techniques, its two peculiar aspects: the determination of the constants of the motion and the regularization at the origin.Research supported by the Consiglio Nazionale delle Ricerche of Italy (C.N.R.-G.N.F.M.).  相似文献   
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