沿主光轴影像的单像空间后方交会方法研究     

康志忠  张祖勋  阳凡林 《武汉大学学报(信息科学版)》2007,32(4):293-296

提出了一种沿主光轴方向影像的单像空间后方交会方法，实现了相机检校和空间后方交会的同时进行。实验证明，该方法达到了比较理想的精度。  相似文献   

城区铅垂线辅助空中三角测量研究   总被引：2，自引：0，他引：2  

张祖勋  张勇 《武汉大学学报(信息科学版)》2007,32(8):659-662,670

根据灭点理论建立了铅垂线辅助空中三角测量理论模型，讨论了控制点的分布和旁向重叠度对附加铅垂线约束的空中三角测量的精度与可靠性的影响，最后结合实际数据对上述铅垂线辅助空中三角测量理论分析结果进行了试验验证。试验结果表明，铅垂线约束可以作为一种控制条件，引入城区航空影像的空中三角测量，以减少传统空三所需的高程控制点数，为城区航空影像的空中三角测量解算提供了一种新的思路。  相似文献   

精密单点定位在GPS辅助航空摄影测量中的应用     

吴晓明  李峰  程如岩 《地理空间信息》2007,5(5):35-38

结合一例航测工程实践,从不同的角度对精密单点定位(PPP)应用于GPS辅助航测的可行性进行了分析。结果表明,PPP的动态定位结果同双差解的符合精度达到cm～dm级,而且将PPP的解算结果应用到GPS辅助空中三角测量中,也取得了同双差方法相当的精度。因此,PPP应用于GPS辅助航空摄影测量中切实可行。  相似文献   

Application of Analytical Modeling to the Far-field Investigation of Tsunami and Oceanic Rayleigh Waves from the 1998 Papua New Guinea Earthquake     

Tatyana?NovikovaEmail author  Bor-Shouh?Huang  Kuo-Liang?Wen 《Pure and Applied Geophysics》2005,162(11):2071-2093

We analyze far-field Rayleigh and tsunami waves generated by the 1998 Papua New Guinea (PNG) earthquake. Using the normal mode theory and Thomson-Haskell matrix formalism we calculate synthetic mareograms of oceanic surface waves excited by finite-dimensional line source and propagated in a flat, multilayered oceanic structure. Assuming that the source of destructive sea waves was the main shock of the PNG event and based on the expression for seismic wave displacement in the far-field zone, we compute the energy of the seismic and tsunami waves and the E_z /E_ts ratio. The results of our modeling are generally consistent with those obtained empirically for events with magnitude 7. Also, treating the results of a submarine slide as a single solitary wave and using the theoretical arguments of Striem and Miloh (1976) we estimate the energy of the tsunami induced by a landslide. The difference between the energy of the seismic tsunami and of the aseismic one is about one order of magnitude.The results of our theoretical modeling show that surface sea waves in the far-field zone account well for seismic origin, although additional tsunami energy from a landslide source could be required to explain the local massive tsunami in the Sissano Lagoon.  相似文献   

A new method for the derivation of the closed nets in the phase diagram space of multisystems. I. The absent phase substitution method     

J. Hu  H. Yin  Z. Duan 《Journal of Metamorphic Geology》2004,22(5):413-425

A new convenient combinatorial method is developed here to derive the invariant points in multisystem closed nets – the absent phase substitution (APS) method. It substantially simplifies the derivation of the closed nets in multisystems with many components and phases. For the multisystems whose total phase number (N_PS) ≤ twice the number of the absent phases (m) in an invariant assemblage, the method can yield regular closed nets with or without globally absent phases; for other multisystems, the method can yield the regular closed nets with globally absent phases. As examples, the APS method was used to predict: (1) the regular closed nets of unary to quinary n + 4‐phase multisystems, unary 6‐phase multisystem and ternary 8‐phase multisystem; (2) the basic properties of the regular closed nets of the quaternary and quinary multisystems with n + 4 and n + 5 phases. Two multisystems were chosen to demonstrate how to select a realistic closed net from the numerous possible closed nets of a complex multisystem, and how to derive a realistic partially closed‐net, closed‐net‐diagram and the related realistic straight‐line‐net‐diagram. Comparisons of our APS method for the derivation of complicated closed nets with other methods indicate that this method is much simpler and more efficient.  相似文献   

天球参考架零点的测定(Ⅲ)─—用不同小行星测零点改正的权重     

王晓彬 《天文研究与技术》1997,(1)

从以往的资料看出，太阳系天体中不同观测对象对天球参考架零点改正的权重是不同的，以不同的小行星为观测对象，其零点改正的结果之间也有较大的差异，因为它们的轨道根数是不相同，本文利用最小二乘法方法分析了不同类型轨道的小行星在测定Ｅ和Ｄ改正时最或然值的偏差量以及必须满足的观测条件。此工作是为今后有效地选取合适的小行星观测来测定零点改正作准备；同时，这一方法也能够分析实测所得到的Ｅ和Ｄ的精度  相似文献   

Some Probability Applications to Oil Exploration     

Anderson  Malcolm  Gullco  Robert S. 《Natural Resources Research》2002,11(1):61-70

In the first part of this paper, a portion of a sedimentary basin is subdivided conceptually into hexagons of equal area. The area of each hexagon is equal to the minimum area an oil field should have to be commercial. Hexagons can be full of oil, or empty. A field size 1 consists of a cell with oil surrounded by six empty cells; a field size 2 consists of two adjacent cells with oil surrounded by eight empty cells, etc. Principles of Percolation Theory are used to determine the probabilility distribution of the areas of the oil fields existing in this portion of the basin. The only piece of information necessary to determine this probability distribution is the Success Ratio (number of successful exploration wells/total number of exploration wells drilled in this portion of the basin). This approach has several practical applications.In the second part of this paper, a probabilistic model is introduced to predict to which extent potential oil traps are filled with oil. The model assumes that the probability that an oil unit will end up in a particular trap, is proportional to the surface area of the trap. The model predicts that independently of the distribution of the trap volumes, there will be a critical trap volume. All the traps having a volume less than this critical volume, will be filled to spill point. An equation is deduced to predict, for all traps having a volume greater than the critical, the volume of oil that can be encountered in the trap, provided the volume of the trap is known.  相似文献   

数字海图点群状特征的识别、量测与综合   总被引：1，自引：0，他引：1  

陆毅  翟京生  杜景海  李树军 《武汉大学学报(信息科学版)》2001,26(2):133-139

空间分布特征的保持是点群自动综合的核心和难点所在,为此,本文定义了4个参量：分布范围、分布密度、分布中心和分布轴线,来描述点群目标的结构化信息。利用Delaunay三角网和Voronoi图两种模型,着重探讨了点群分布特征的识别和量测问题,并在识别与量测的基础上,通过Voronoi图的动态构建,给出了点群自动综合模型,通过实际岛群数据的检测,证明了模型的正确性与可行性。  相似文献   

2004年7月两次强对流天气过程的对比分析   总被引：2，自引：2，他引：2  

王雷  赵海林  张蔺廉 《气象》2005,31(11):65-68

对两次强对流天气过程的影响系统、物理量场和雷达回波特征等进行了对比分析.分析表明：两次强对流过程有许多相似之处,高、低空西南急流适宜配置而引起的高低层动力场的耦合是强对流发生的动力条件,强对流发生在低层露点锋区及低层水汽通量和散度辐合、高层则相应辐散的大值区域.高低层相对散度正值越大,其所产生的雨量也就越大.多普勒雷达反射率因子图上弓状回波的后侧出现下沉入流急流,相应速度图上的速度值越大,回波移动速度越快,预示着所造成的地面风力也就越大.  相似文献   

转换波精确无迭代速度分析     

何兵寿  张会星  崔小芹 《物探与化探》2005,29(5):443-446

提出了一种随着速度比与转换点深度的变化而动态抽道的转换波速度分析方法,实现了扫描叠加速度、转换点深度与共转换点道集的一一对应,是一种真正意义上的共转换点无迭代速度分析技术,理论模型试算与实际地震资料处理都证明了此方法的正确性与有效性.  相似文献