高原复杂地形条件下慢天线测量值的订正   总被引：2，自引：0，他引：2       下载免费PDF全文

范祥鹏  张广庶  王彦辉  李亚珺  张彤  武斌 《高原气象》2011,30(4):1046-1051

利用青海大通地区高精度GPS时钟同步的7站慢电场变化资料,以点偶极模式为基础,运用穷举法并结合非线性最小二乘法对发生在2009年野外观测期间11个负地闪的26次回击产生的电场变化进行了拟合。对拟合结果最优的各站订正系数进行了统计,求出了以主观测站为基准的各站慢天线订正系数,即各站慢天线观测值受海拔高度和植被遮挡等因素影...  相似文献   

基于PSInSAR技术的海原断裂带地壳形变初步研究   总被引：7，自引：4，他引：3       下载免费PDF全文

屈春燕  单新建  宋小刚  张桂芳  张国宏  郭利民 《地球物理学报》2011,54(4):984-993

常规差分干涉测量(DInSAR)受时间、空间失相干的严重制约和和大气延迟等相位误差的影响,难以实现对长期累积微小地壳形变场的有效探测.PSInSAR技术克服了常规DInSAR的局限性,能够高精度监测微小地壳形变.本文首先介绍了PSInSAR技术的算法模型和处理方法.该方法通过二维线性相位模型,对时序干涉图象上相干点目标...  相似文献   

Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program     

Robert B. Hunter  Timothy S. CollettRay Boswell  Brian J. Anderson  Scott A. DigertGordon Pospisil  Richard BakerMicaela Weeks 《Marine and Petroleum Geology》2011,28(2):295-310

The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The “Mount Elbert” site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate scientific research programs can be safely, effectively, and efficiently conducted within ANS infrastructure. The program success resulted in a technical team recommendation to project management to drill and complete a long-term production test within the area of existing ANS infrastructure. If approved by stakeholders, this long-term test would build on prior arctic research efforts to better constrain the potential gas rates and volumes that could be produced from gas hydrate-bearing sand reservoirs.  相似文献   

桩身轴向应变的连续监测法     

李光煜  陈东 《地震工程学报》2011,33(Z1)

静力试桩中桩身轴向应变是分析荷载传递机理的基础。滑动测微计可连续地测定桩身每米内的平均应变,通过荷载-应变关系曲线可较准确地计算轴向力、摩阻力、端阻力、负摩阻力;水平试桩时安装二条测管可准确地推算挠度曲线、最大弯矩点,临界荷载、极限荷载等桩基设计的主要参数,还可全面地评价桩身质量。该仪器不仅可用于各类试桩,还可用于各类岩土工程的现场位移监测。  相似文献   

对流层投影函数对精密单点定位精度的影响分析     

李施佳  蔡昌盛  李佳霖  易志鹏 《全球定位系统》2013,(5):22-26

对流层延迟误差是GPS定位中的一项重要的误差源,随着精密单点定位（PPP）技术的不断发展,该误差影响并制约着GPS精密单点定位精度的进一步提高。基于GPS观测值,比较分析了各种对流层投影函数模型对GPS精密单点定位精度的影响,得出了有益的结论。  相似文献   

Search for point-like sources of cosmic rays with energies above 10 eV in the HiRes-I monocular data set     

《Astroparticle Physics》2007,27(6):512-520

We report the results of a search for point-like deviations from isotropy in the arrival directions of ultra-high energy cosmic rays in the northern hemisphere. In the monocular data set collected by the High-Resolution Fly’s Eye, consisting of 1525 events with energy exceeding 10^18.5 eV, we find no evidence for point-like excesses. We place a 90% c.l. upper limit of 0.8 hadronic cosmic rays/km² yr on the flux from such sources for the northern hemisphere and place tighter limits as a function of position in the sky.  相似文献   

Limitations Of The Tangent Plane Approximation For Wide-field Imaging Using The Mauritius Radio Telescope   总被引：1，自引：0，他引：1  

N. Oozeer  N. Udaya Shankar 《Astrophysics and Space Science》2002,282(1):43-55

The Mauritius Radio Telescope (MRT) is a Fourier synthesis, non-coplanar T array. The primary objective of the telescope is to survey the southern sky at 151.5 MHz in the declination range -70^° to -10^°. Due to non-coplanarity, wide-field imaging and deconvolution of wide field images made using MRT are challenging problems in applications of radio interferometric techniques. This paper discusses the usefulness and limitations of the tangent plane approximation in transforming the measured visibilities to wide field images and in estimating the point spread function (PSF) required for the deconvolution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

基于普通数码相机的近景摄影测量方法与精度的试验研究   总被引：3，自引：0，他引：3  

张慧鑫  李非栗  雷巨光 《北京测绘》2008,(4)

普通数码相机由于体积小、重量轻、价格低廉、像素几何位置精度高、影像可直接输入计算机进行处理等优点备受人们青睐。随着数字摄影测量技术的发展,数码相机分辨率的不断提高,人们开始考虑能否将普通数码相机应用于工程实践。本文以普通数码相机作为影像信息的获取手段,就控制点的数量、分布、精度、影像获取及其量测方法、数据处理解算方法、解算精度等问题进行了研究。  相似文献   

激光铅垂仪向上投点在地铁隧道工程中进行联系测量的实践     

高绍伟 《北京测绘》2008,(2):57-60

盾构法地铁隧道施工测量中,提高联系测量对隧道贯通起着决定的作用。本文对地铁施工测量贯通测量的误差来源进行了分配,对二井定向利用激光铅垂仪向上投点方案进行了精度分析,并和钢丝投点法的计算成果进行了比较,提出了激光铅垂仪向上投点法方案措施。  相似文献   

MAPGIS数据向ARCGIS转换研究   总被引：4，自引：0，他引：4  

彭晶晶  戴爱德 《国土资源信息化》2008,27(1):19-25

在将MapGIS文件向ArcGIS文件转换的过程中,为使文件正确显示,按照目前通用的方法转换后通常需要进行复杂的手工调整,而转换的数据量较大,这将耗费大量的人力、物力和时间。本次设计的实施方案就是避免采用中间格式(如E00)进行转换,运用VB编程语言对这两个GIS平台进行二次开发。通过MapGIS提供的MapGIS SDK开发包调用相应的接口实现对MapGIS图形数据文件的访问,通过ArcGIS提供的开发包ArcOBJECTS调用相应的接口实现数据向目标文件的写入和文件的生成。开发出可以实现MapGIS到ArcGIS进行数据无损转换的工具。实现ArcGIS平台对MapGIS数据的有效读取。  相似文献