GPS RTK配合GPRS通讯模块在管线测量中的应用     

李涛  ;周长胜  ;孙磊  ;郑伟安 《山东地质》2008,(7):71-73

通过对比GPSRTK常规PDL电台与GPRS通讯模块在外业测量过程中效果,并从施工组织、生产效率与精度评定等方面进行比较,证实GPS测量技术具有快捷、精确、操作简便等优点,因而在长距离输油管道中线测量中,应用GPSRTK配合GPRS通讯模块的方法,可以取得提高作业效率及节省外业测量费用等效果。  相似文献   

精密全站仪标称精度的实现途径之二——角度测量精度的保障     

蒋利龙  杜向锋  王宇会 《测绘工程》2008,17(3):46-49

大气折射是角度测量的主要误差源,也是实现精密全站仪标称精度的主要障碍。文中通过分析大气对角度测量精度的影响,讨论了利用气象元素直接计算大气垂直折光角和利用对向EDM三角高程测量结果反演大气垂直折光角的方法,同时还讨论了观测垂直角的适宜时间问题。采用这些方法能够有效地削减大气折射对垂直角观测结果的影响,保证垂直角测量的精度。  相似文献   

高层建筑倾斜变形数据处理   总被引：1，自引：1，他引：0  

王有良  唐跃刚 《测绘科学》2008,33(2):165-166

沉降测量是建筑物变形分析的重要手段,本文介绍用线性回归和平面回归方法对建筑物倾斜进行变形分析,对线性回归和平面回归的适用性作了说明,并结合实例说明了在建筑物倾斜变形分析中运用线性回归分析法和平面回归分析法的实用性和可靠性。  相似文献   

铁岭组中风化柱状叠层石灰岩强度确定概率方法     

张中琼  陈剑平  王清 《工程地质学报》2008,16(5):667-671

研究区大量分布中风化柱状叠层石灰岩, 岩石强度具有很强的变异性和区域性, 而岩石强度是影响边坡稳定的重要因素。要进行边坡稳定性评价, 就需要对研究区现场试验数据作为随机变量进行概率统计分析, 获取可靠的岩石强度指标。本文通过对研究区内中风化柱状叠层石灰岩( t23 ) 现场点荷载实验数据进行统计分析, 利用x2 检验进行拟和, 得到岩石强度的概率密度函数和概率分布形式, 抗压强度和抗拉强度均服从对数正态分布。在此基础上, 结合相近岩性岩石强度的拟和结果, 建立区内中风化柱状叠层石灰岩点荷载试验强度概率分布函数。运用Bayes估计推断区域内中风化柱状叠层石灰岩岩石点荷载强度, 得到岩石抗压强度预测值为72. 42 MPa, 抗拉强度预测值为2. 29 MPa, 相对误差较小, 样本信任度达到70%以上。该方法对于岩石强度估计是有效的, 由该方法所得到的估计值对研究区边坡稳定性评价以及后期边坡治理都具有重要的实践意义。  相似文献   

运动学涡度的理论与实践   总被引：5，自引：0，他引：5  

郑亚东  王涛  张进江 《地学前缘》2008,15(3):209-220

一般剪切作用下,碎斑或顺剪切作用方向向前或逆向旋转向两特征方向或流脊(非旋转方向)靠拢。高应变条件下,二长比大于一特定值的碎斑,当其顺向或逆向旋转至以特征方向为渐近线的双曲线的稳定翼上时,便稳定下来不再旋转。二长比小于该值的碎斑将不断向前旋转。这一特定值位于该双曲线的顶点,相应的临界形态因子(B*)或/和两特征方向间夹角的余弦定义为运动学涡度(Wk)。Wk是确定一相关韧性变形带纯剪切和简单剪切组分相对大小的重要度量,是根据内旋转(涡度)与线应变速率之间的比值而定的数值度量。就变形带而言,一般剪切带的运动学涡度变化为0~1,纯剪切为零,简单剪切为1。这是一非线性尺度,纯剪切和简单剪切各占50%的运动学涡度为0.71,而不是0.5。运动学涡度可通过计算、图解(双曲线网(PHD)、刚性颗粒网(RGN)法、Passchier图解、Wallis图解)、极摩尔圆法和应力或瞬时增量应变方向获得。运动学涡度与有限应变测量相结合很可能是估算一地地壳减薄/伸展量或增厚/缩短量的最佳途径。变形过程中运动学涡度很可能变化,应根据不同时期形成的构造获得相应时期的运动学涡度。  相似文献   

测氡法和瞬变电磁法在探测煤矿采空区的应用   总被引：1，自引：1，他引：0  

杨建军  申燕  刘鸿福 《物探与化探》2008,32(6)

介绍了活性炭测氡法探测采空区的基本原理。用测氡仪器测量其氡的衰变子体放射出伽马射线的强度,从而了解氡气浓度的高低,便可知采空区的位置。根据采空区的地球物理特征,利用瞬变电磁法,通过分析拟视电阻率断面图,准确地探测出了采空区的位置。以探测山西省西山煤电集团有限公司东曲矿采空区为例,来说明活性炭测氡法和瞬变电磁法在探测采空区是可行的。  相似文献   

Maps of Titan's surface from 1 to 2.5 μm     

Athena Coustenis  Mathieu Hirtzig  Pierre Drossart  Michel Combes 《Icarus》2005,177(1):89-105

We have acquired resolved images of Titan with the adaptive optics systems PUEO/KIR at the CFHT (Hawaii) and NAOS/CONICA at the VLT (Chile). We report here on images and maps (when data at several orbital phases are available) of Titan's surface from observations taken during the last 4 years (2001-2004) in all the methane windows between 1 and 2.5 μm (namely, at 1.08, 1.28, 1.6, and 2 μm). We present the only complete maps of Titan currently available at 1.3 μm, a spectral window where Titan appears particularly bright in spectroscopy, with a resolution of about 200 km at best on the ground. Our surface maps show the bright and dark regions sharing Titan's landscape with as much detail as possible from the ground and with high contrast in most cases. From the information gathered by comparing the maps at different wavelengths we derive constraints on the ground's composition. Our results could complete/optimize the return of the Cassini-Huygens mission.  相似文献   

Constraining the surface properties of Saturn's icy moons, using Cassini/CIRS emissivity spectra     

J.M. Carvano  A. Migliorini  A. Barucci  the CIRS Team 《Icarus》2007,187(2):574-583

We have conducted a search for emissivity features in the thermal infrared spectrum of the icy satellites of Saturn, Phoebe, Iapetus, Enceladus, Tethys, and Hyperion, observed by the Composite Infrared Spectrometer (CIRS) on board the Cassini spacecraft. Despite the heterogeneity of the composition of these bodies depicted by Earth-based and Cassini/VIMS observations, the CIRS spectra of all satellites are undistinguishable from black-body spectra, with no detectable emissivity feature. However, several materials, which have been detected on the surface of the same bodies, present emissivity features in the analyzed spectral range. In particular, water ice presents features with sufficient contrast to be detected by CIRS. Here we study the physical causes of the absence of features by simulating the effects of intimate mixtures using models of directional emissivity for optically thick surfaces for different particle sizes and abundances, and porosities. The simulations include a set of materials detected on the Phoebe's surface, like water ice, hydrated silicates, and organics. We find that featureless spectra can be produced in three scenarios: (1) ice particles with large sizes, (2) mixtures of ices dominated by dark contaminants, and (3) small particles with large porosity. Constraints imposed by the NIR spectra of the satellites favors the latter scenario as the more likely explanation to the absence of emissivity features on the icy satellites of Saturn.  相似文献   

利用钻孔实测数据计算地下岩层产状的方法     

刘德正 《山东国土资源》2007,23(11):1-5,10

讨论了不同孔段组合条件下地下岩层产状的计算方法,全面而且精确地再现赤平极射投影的图解结果:对双斜孔段组合能够求出所有可能的产状解(包括逆向穿层解);对直斜孔段组合、三斜孔段组合、连续多斜孔段组合,以及双斜孔段组合中具同向穿层单解的计算对象能够给出最可能的产状解。  相似文献   

Saturn's rings in the thermal infrared     

L. Spilker  C. Ferrari  J. N. Cuzzi  M. Showalter  J. Pearl  B. Wallis 《Planetary and Space Science》2003,51(14-15):929

This paper reviews our current knowledge of Saturn's rings’ physical properties as derived from thermal infrared observations. Ring particle composition, surface structure and spin as well as the vertical structure of the main rings can be determined. These properties are the key to understand the origin and evolution of Saturn's rings. Ring composition is mainly constrained by observations in the near-infrared but the signature of some probable contaminants present in water ice may also be found at mid-infrared wavelengths. The absence of the silicate signature limits nowadays their mass fraction to 10^−7±1. Recent measurements on the thermal inertia of the ring particle surface show it is very low, of the order of 5±2 Jm⁻² K⁻¹ s^−1/2. New models and observations of the complete crossing of the planetary shadow are needed to attribute this low value either to compact regoliths covered by cracks due to collisions and thermal stresses or to large fluffy and irregular surfaces. Studies of the energy balance of ring particles show a preference for slowly spinning particles in the main rings. Supplementary observations at different phase angles, showing the temperature contrast between night and day sides of particles, and new models including finite spin and thermal inertia, are needed to constrain the actual spin distribution of ring particles. These results can then be compared to numerical simulations of ring dynamics. Many thermal models have been proposed to reproduce observations of the main rings, including alternative mono- or many-particles-thick layers or vertical heterogeneity, with no definitive answer. Observations on the lit and dark faces of rings as a function of longitude, at many incidence and emission angles, would provide prime information on the vertical thermal gradient due to interparticle shadowing from which constraints on the local vertical structure and dynamics can be produced. Future missions such as Cassini will provide new information to further constrain the ring thermal models.  相似文献