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91.
本文提出一种稳健估计的方法,作为对现有最小二乘方法的改进,对人造卫星激光测距资料进行预处理,判别异常值,估计中误差。该方法将使异常值的剔除更加稳定可靠;在多数情况下,可不借助人工屏幕处理,实现自动化,该方法有50%崩溃点,且不受端点效应的影响。 相似文献
92.
J. A. Kamalakar K. V. S. Bhaskar A. S. Laxmi Prasad R. Ranjith K. A. Lohar R Venketeswaran T. K. Alex 《Journal of Earth System Science》2005,114(6):725-731
Lunar Laser Ranging Instrument (LLRI) proposed for the first Indian lunar mission Chandrayaan-1 is aimed to study the topography
of the Moon’s surface and its gravitational field by precisely measuring the altitude from a polar orbit around the Moon.
Altimetry data close to the poles of the Moon would also be available from the instrument, which was not covered by earlier
missions. This instrument supplements the terrain mapping camera and hyperspectral imager payloads on Chandrayaan-1. The instrument
consists of a diode pumped Nd:YAG pulsed laser transmitter having 10 nsec pulse width and a receiver system. The receiver
system features 17 cm diameter Ritchey—Chrétien collecting optics, Si Avalanche Photo Detector (APD), preamplifiers, constant
fraction discriminators, time-of-flight measurement unit and spacecraft interface. Altimeter resolution of better than 5 m
is targeted. The received signal strength of LLRI depends on laser pulse backscatter from the Moon’s surface. Moon’s surface
being a poor reflector, the choice of receiver size and its type and the selection of detector play an important role in getting
a good signal-to-noise ratio and in turn achieving the target resolution. At the same time, the spacecraft puts a limitation
on payload size and weight. This paper discusses the proposed LLRI system for Chandrayaan-1 and signal-to-noise ratio estimation. 相似文献
93.
94.
利用正交试验法研究了高功率CO2激光工艺参数对钻杆接头表面硬化效果的影响,利用显微硬度计测定了硬化层硬度的分布规律及组织特征,采用计算机回归处理分析得出了P、D、V、E对硬化层面积大小因子h·b影响的表达式。研究结果为高功率CO2激光强化钻杆接头提供了一定的依据 相似文献
95.
给出了太阳系质心参考系(BRS)和地心参考系(GRS)中的相对论激光测距理论模型,并且利用现有的坐标变换关系证明两种模型在毫米级的精度上是完全等价的。最后指出,由IERS推荐的坐标变换公式与激光测距模型之间存在不自洽性,这种不自恰性对激光测月(LLR)的影响可达约10cm。 相似文献
96.
97.
G. Gutirrez-Alonso J. Fernndez-Surez T.E. Jeffries G.A. Jenner M.N. Tubrett R. Cox S.E. Jackson 《Tectonophysics》2003,365(1-4):221
If reconstruction of major events in ancient orogenic belts is achieved in sufficient detail, the tectonic evolution of these belts can offer valuable information to widen our perspective of processes currently at work in modern orogens. Here, we illustrate this possibility taking the western European Cadomian–Avalonian belt as an example. This research is based mainly on the study and interpretation of U–Pb ages of more than 300 detrital zircons from Neoproterozoic and Early Paleozoic sedimentary rocks from Iberia and Brittany. Analyses have been performed using the laser ablation–ICP–MS technique. The U–Pb data record contrasting detrital zircon age spectra for various terranes of western Europe. The differences provide information on the processes involved in the genesis of the western European Precambrian terranes along the northern margin of Neoproterozoic Gondwana during arc construction and subduction, and their dispersal and re-amalgamation along the margin to form the Avalonia and Armorica microcontinents. The U–Pb ages reported here also support the alleged change from subduction to transform activity that led to the final break-up of the margin, the birth of the Rheic Ocean and the drift of Avalonia. We contend that the active northern margin of Gondwana evolved through several stages that match the different types of active margins recognised in modern settings. 相似文献
98.
LIU Fulai SHEN Qihan Institute of Geology Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》2003,77(1):28-35
The early Precambrian khondalite series is widely distributed in the Jining-Zhuozi-Fengzhen-Liangcheng area, southeastern Inner Mongolia. The khondalite series mainly consists of sillimanite garnet potash feldspar (or two-feldspar) gneiss and garnet biotite plagioclase gneiss. These gneissic rocks have commonly experienced granulite-facies metamorphism. In zircons separated from sillimanite garnet potash feldspar gneisses, many mineral inclusions, including Sil, Grt, Ky, Kfs, Qtz and Ap, have been identified by the Laser Raman spectroscopy. Generally, prograde metamorphic mineral inclusion assemblages such as Ky + Kfs + Qtz + Ap and Ky + Grt + Kfs + Qtz are preserved in the core of zircon, while peak granulite-facies metamorphic minerals including Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap are identified in the mantle and rim of the same zircon. However, in some zircons are only preserved the peak metamorphic minerals such as Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap from core to ri 相似文献
99.
人工合成包裹体的实验研究及其在激光拉曼探针测定方面的应用 总被引:21,自引:11,他引:21
利用愈合人工水晶裂隙合成人工流体包裹体的技术,在0.5~1kb,350~800℃的范围内,对纯H2O体系、NaCl-H2O体系、KCl—H2O体系进行了人工合成包裹体实验研究。并对这些合成的包裹体进行了详细的测温学研究,证实了合成包裹体是母液成分的真实代表,完全可以用来做为自然界包裹体研究的标样。同时利用合成包裹体采集了均一、和冷冻状态下的拉曼谱,讨论了合成包裹体在激光拉曼探针测定方面的某些可能的应用。研究表明,合成包裹体是了解包裹体的形成机理和进行地质流体性质研究的一种十分有效的手段,在地质流体和实验地球化学研究领域有着广阔的应用前景。 相似文献
100.
Muriel Llubes Nicolas Florsch Jean-Paul Boy Martine Amalvict Pascal Bonnefond Marie-Noëlle Bouin Stphane Durand Marie-France Esnoult Pierre Exertier Jacques Hinderer Marie-Franoise Lalancette Frdric Masson Laurent Morel Joëlle Nicolas Mathilde Vergnolle Guy Wppelmann 《Comptes Rendus Geoscience》2008,340(6):379-389
We have organised afield study of ocean tide loading in the northwestern part of France, where tidal amplitudes are known to be among the highest in the world. GPS and gravimetric techniques have already proved their capability to measure such weak and high-frequency signals. In this study, these classical observations are complemented with less usual techniques, such as tiltmeter and Satellite Laser Ranging (SLR) measurements. We present here the preliminary results for a common period of observations spanning from 12–19 May 2004. Additional measurements from the French Transportable Laser Ranging Station (FTLRS) were available during September and October 2004. Observation residuals are computed as the difference between the observed and the predicted time signals. We obtain small RMS residuals for GPS measurements (2.5/3.1/4.5 mm for the eastward, northward and upward components), for absolute and relative gravimetry (9 nm/s2 and 13 nm/s2) and for tiltmeters (0.05 μrad for EW component). We also fit the amplitude of the main M2 tidal constituent to FTLRS observations and we find a value of 3.731 cm, which is comparable to the theoretical value. 相似文献