距离交会加密控制点分析与应用

阐述了距离交会加密测量控制点的原理和实际应用,并用一种简单的方法估算其误差。     

基于GPS/IMU的红外影像直接定位技术

研究无控制点情况下的红外影像目标快速定位技术,有利于发挥红外遥感的测绘应用潜力。首先介绍了基于GPS/IMU的目标定位原理与方法;然后实验验证了红外影像多像前方交会和GPS/IMU辅助红外影像光束法区域网平差的可行性;并分析了误差产生的原因。实验证明,航空红外遥感在GPS/IMU组合系统的配合下,能满足目标探测与预警的精度要求,具有实用价值。     

Barrier-corridor effect of terrain on monsoons longitudinal range-gorge in Southwest China

地形格局对大气环流与区域气候具有重要影响。已有研究认为纵向岭谷区主要受到印度洋季风与太平洋季风的共同影响,二者在哀牢山山脉附近交汇,哀牢山山脉是一条重要的地理分界线。本文从大气环流、水汽输送、区域气候、河川径流以及植物稳定氧同位素等多个方面研究发现：纵向岭谷地区主要受印度洋季风的影响,太平洋季风的影响在8月份有一定的作用,但不够明显;在地形格局作用下,地表水汽、降水以及河川径流在纵向岭谷区表现出明显的纬向差异、经向延伸的特征;大流环流、水汽输送、区域气候以及河川径流等的空间差异,是特殊环境对水热再分配的结果,即“通道一阻隔”作用的效应;这些差异不是地理地带性的表现,而是非地带性作用的结果;这种“通道一阻隔”作用导致地表水热条件的再分配,是该区生态地理格局形成与演化的主驱动力之一。纵向岭谷地形对季风的“通道-阻隔”作用导致了一系列地理要素的空间分异和相关联的生态效应。     

锦屏二级水电站交叉隧洞围岩稳定性分析

锦屏二级水电站引水隧洞具有埋深大等复杂的地质情况,因此在已有隧洞的基础上开挖与之相交的主隧洞,主隧洞（特别是在交叉部处）围岩性质弱化并且围岩自身稳定性降低。因此结合高地应力区深埋隧洞工程,通过3D弹塑性有限元数值仿真模拟,并且通过模型试验,分析围岩在开挖中的应力释放及应力分布规律,为深埋隧洞交叉段监控量测系统的设计、施工方案优化及安全控制提供依据。     

A comparison of the Iberian and Ebro Basins during the Permian and Triassic, eastern Spain: A quantitative subsidence modelling approach

The Permian–Triassic sediments of the Iberian Plate are a well studied case of classical Buntsandstein–Muschelkalk–Keuper facies, with good sedimentological interpretations and precise datings based on pollen and spore assemblages, ammonoids and foraminifera. Synrift–postrift cycles are recorded in these facies, but there are only a few studies of quantitative subsidence analysis (backstripping method) and only a previous one using forward modelling for the quantification of synrift–postrift phases of this period.Here we present the results obtained by the quantitative analysis of fourteen field sections and oil-well electric log records in the Iberian and Ebro Basins, Spain. Backstripping analysis showed five synrift phases of 1 to 3 million years duration followed by postrift periods for the Permian–Triassic interval. The duration, however, shows lateral variations and some of them are absent in the Ebro Basin. The forward modelling analysis, assuming local isostatic compensation, has been applied to each observation point using one-layer and two-layer lithospheric configurations. The second one shows a better fit between observation and model prediction in a systematic way, so a two layer configuration is assumed for the sedimentary basin filling analysis. Lithospheric stretching factors β and δ obtained in the forward modelling analysis are never higher than 1.2, but sometimes β < 1 and simultaneously δ > 1 in the same section. If surficial extension is compensated by deep compression either at the roots of the rift basins or in far-away zones is not yet clear, but this anomaly can be explained using a simple shear extensional model for the Iberian and Ebro basins.     

水平定向对接穿越及导向技术研究

水平定向对接穿越技术有效解决了传统水平定向钻进无法完成长距离穿越,以及无法穿越两侧均含砾石等复杂地层的问题。介绍了水平定向对接穿越技术以及该技术在国内外的应用,详细分析了基于三轴加速度计和三轴磁阻传感器的对接穿越导向技术,基于轴向磁铁产生的磁场建立了对接模型。     

基于多片空间后方交会的CCD相机检校

近年来,CCD相机逐步应用于近景摄影测量、低空摄影测量。影响摄影测量成果精度的重要因素之一是相机的技术参数,因此相机技术参数的检校是保证成果质量能否满足精度要求的关键问题之一。文中通过单片空间后方交会和多片空间后方交会的比较试验,分别对两种方法实施了精度分析和可靠性分析,总结得出多片空间后方交会是一种更为可靠的CCD相机检校方法,且运用多片空间前方交会方法进一步验证了多片空间后方交会检校成果的可靠性。     

Modeling the connectivity and intersection of hydraulically loaded cracks with in situ fractures in rock

The interaction of an advancing hydraulically loaded crack and in situ fracture network can yield highly complex patterns. We model the connectivity of cells in a finite element domain and in a fracture network by a simplicial complex data structure. The complete adjacency information between cells is determined by one level down facet and one level up cofacet neighborhood information. Combined with a disjoint set data structure, explicit algorithms are derived to efficiently track network connectivity and load transfer between independent fracture sets. We also propose an approach to regularize the application of hydraulic load to newly intersected in situ cracks to smoothen the transition of pressure on intersected cracks from ambient to hydraulic pressure and to avoid the sudden loading of the entire length of these cracks. Numerical results demonstrate the performance of crack connectivity and load transfer models and the effect of regularization model. The results show that as the angle between an incoming hydraulically loaded crack and an in situ crack increases, the effect of in situ crack shifts from slight realignment to diversion/offsetting of the loaded crack. As the angle difference approaches the normal angle, the loaded crack tends to penetrate through the in situ crack. The proposed schemes are also used for transient simulation of 2D reservoirs with multiple perforations surrounded by in situ cracks with and without a bias in the distribution of their orientation. It was shown that from 2 perforations with angles closer to in situ cracks at low loading rates to all perforations at higher loading rates can result in active hydraulic crack propagation. The h‐adaptive method of asynchronous space‐time discontinuous Galerkin method is used to exactly track complex fracture patterns in these dynamic fracture simulations.     

基于切点前方交会法的大型烟囱倾斜观测最佳方案设计

分析了切点前方交会对大型烟囱倾斜变形观测精度的影响,设计了实用的最佳交会图形,并通过实际工程运用,证明了提出的最佳方案的正确性。     

基于广义点摄影测量的后方交会与前方交会方法研究

广义点摄影测量将传统的点摄影测量和当代发展的线摄影测量以及无穷远点理论综合升华,将摄影测量中处理的物理意义上的点扩展到数学意义上的广义点.本文主要研究广义点摄影测量理论下的后方交会和前方交会解算方法.分析评价了不同控制线分布情况对后方交会精度的影响;依据前方交会原理,对闭合直线段和圆进行了三维重建,取得了良好的效果.