水下无源导航系统仿真匹配算法研究   总被引：15，自引：1，他引：15  

张飞舟  侣文芳  晏磊  葛远声 《武汉大学学报(信息科学版)》2003,28(2):153-157

针对水下无源导航(地形辅助导航)系统的特点，充分利用各种海洋地理特征传感器获取信息，进行数据预处理、算法分析、性能评估，然后进行智能数据融合，进而完成水下无源导航系统模块化的仿真设计，为水下无源导航系统的进一步研究提供可行的方法和技术。仿真结果表明，采用水下地形匹配辅助导航，能够有效地修正惯导误差达到设计要求，为真实海洋环境下的精确导航提供可靠的技术依据。  相似文献   

基于GPS基准站网的GPS测量   总被引：5，自引：0，他引：5  

胡丛玮  刘大杰 《现代测绘》2003,26(1):10-13

采用基于GPS基准网的GPS测量可以提高GPS测量的可靠性和准确性 ,可以消除和减小GPS测量观测值中与时间和空间相关的大气误差和轨道误差的影响 ,使中、长距离快速静态定位和RTK动态定位成为现实 ,还具有可直接得到WGS84Z坐标等优点。本文介绍基于GPS基准站网的GPS测量 ,简要地论述GPS虚拟参考站法VRS和区域改正数法FKP的原理、方法和特点 ,以及目前实施中存在的一些问题  相似文献   

Laser Ablation ICP-MS Analysis of Geological Materials Prepared as Lithium Borate Glasses   总被引：9，自引：0，他引：9  

Stephen M. Eggins 《Geostandards and Geoanalytical Research》2003,27(2):147-162

A simple, rapid and precise method is described for determining trace elements by laser ablation (LA)-ICP-MS analysis in bulk geological materials that have been prepared as lithium borate glasses following standard procedures for XRF analysis. This approach reliably achieves complete sample digestion and provides for complementary XRF and LA-ICP-MS analysis of a full suite of major and trace elements from a single sample preparation. Highly precise analysis is enabled by rastering an ArF excimer laser (λ= 193nm) across fused samples to deliver a constant sample yield to the mass spectrometer without inter-element fractionation effects during each analysis. Capabilities of the method are demonstrated by determination of twenty five trace elements (Sc, Ti, V, Ga, Rb, Sr, Y, Zr, Nb, Cs, Ba, REE, Hf, Ta, Pb, Th and U) in a diverse range of geological reference materials that includes peridotites, basalts, granites, metamorphic rocks and sediments. More than 90% of determinations are indistinguishable from published reference values at the 95% confidence level. Systematic bias greater than 5% is observed for only a handful of elements (Zr, Nb and U) and may be attributed in part to inaccurate calibration values used for the NIST SRM 612 glass in the case of Zr and Nb. Detection limits for several elements, most notably La, are compromised at ultra-trace levels by impurities in the lithium borate flux but can be corrected for by subtracting appropriate procedural blanks. Reliable Pb analysis has proved problematic due to variable degrees of contamination introduced during sample polishing prior to analysis and from Pt-crucibles previously used to fuse Pb-rich samples. Scope exists for extending the method to include internal standard element/isotope spiking, particularly where integrated XRF analysis is not available to characterise major and trace elements in the fused lithium borate glasses prior to LA-ICP-MS analysis.  相似文献   

A Reappraisal of Rb, Y, Zr, Pb and Th Values in Geochemical Reference Material BHVO-1     

William J. Chazey III  Clive R. Neal  Jinesh C. Jain  William S. Kinman 《Geostandards and Geoanalytical Research》2003,27(2):181-192

The geochemical reference material BHVO-1 was analysed by a variety of techniques over a six year period. These techniques included inductively coupled plasma-mass spectrometry and atomic emission spectroscopy (ICP-MS and ICP-AES, respectively), laser ablation ICP-MS and spark source mass spectroscopy. Inconsistencies between the published consensus values reported by Gladney and Roelandts (1988, Geostandards Newsletter) and the results of our study are noted for Rb, Y, Zr, Pb and Th. The values reported here for Rb, Y, Zr and Pb are generally lower, while Th is higher than the consensus value. This is not an analytical artefact unique to the University of Notre Dame ICP-MS facility, as most of the BHVO-1 analyses reported over the last ten to twenty years are in agreement with our results. We propose new consensus values for each of these elements as follows: Rb = 9.3 ± 0.2 μg g-1 (compared to 11 ± 2 μg g-1), Y = 24.4 ± 1.3 μg g-1 (compared to 27.6 ± 1.7 μg g-1), Zr = 172 ± 10 μg g-1 (compared to 179 ± 21 μg g-1), Pb = 2.2 ± 0.2 μg g-1 (compared to 2.6 ± 0.9 μg g-1) and Th = 1.22 ± 0.02 μg g-1 (compared to 1.08 ± 0.15 μg g-1).  相似文献   

Geoid determination using adapted reference field, seismic Moho depths and variable density contrast   总被引：4，自引：0，他引：4  

H. A. Abd-Elmotaal  N. Kühtreiber 《Journal of Geodesy》2003,77(1-2):77-85

 The traditional remove-restore technique for geoid computation suffers from two main drawbacks. The first is the assumption of an isostatic hypothesis to compute the compensation masses. The second is the double consideration of the effect of the topographic–isostatic masses within the data window through removing the reference field and the terrain reduction process. To overcome the first disadvantage, the seismic Moho depths, representing, more or less, the actual compensating masses, have been used with variable density anomalies computed by employing the topographic–isostatic mass balance principle. In order to avoid the double consideration of the effect of the topographic–isostatic masses within the data window, the effect of these masses for the used fixed data window, in terms of potential coefficients, has been subtracted from the reference field, yielding an adapted reference field. This adapted reference field has been used for the remove–restore technique. The necessary harmonic analysis of the topographic–isostatic potential using seismic Moho depths with variable density anomalies is given. A wide comparison among geoids computed by the adapted reference field with both the Airy–Heiskanen isostatic model and seismic Moho depths with variable density anomaly and a geoid computed by the traditional remove–restore technique is made. The results show that using seismic Moho depths with variable density anomaly along with the adapted reference field gives the best relative geoid accuracy compared to the GPS/levelling geoid. Received: 3 October 2001 / Accepted: 20 September 2002 Correspondence to: H.A. Abd-Elmotaal  相似文献   

建设我国现代大地测量基准的思考   总被引：7，自引：0，他引：7  

陈俊勇 《武汉大学学报(信息科学版)》2003,(Z1)

建设现代大地测量基准方面的进展主要表现在IGS服务和ITRF的系列精化 ,ITRF2 0 0 0是ITRF中迄今最为精确、测站最为稠密的地面坐标参考框架 ;2 0 0 1年推出新的WGS84,其成果标以WGS84(G1 1 5 0 )。考虑和顾及现代大地测量的特点 ,结合中国实际 ,我国现代大地测量基准应着重考虑四个方面的基本要素 :高精度、涵盖全部陆海国土、三维、动态。建设我国现代大地测量基准是为用户在我国任何地点、任何时间提供及时、可靠、适用的地理空间基础框架 ,其任务应包括建立我国现代化的平面基准、高程基准和重力基准等。  相似文献   

国家地理空间信息基准框架工程建设     

张燕平  张全德  张江齐  岳建利 《武汉大学学报(信息科学版)》2003,(Z1)

提出了国家地理空间信息基准框架内改进与更新原有的大地坐标基准、高程基准和重力基准的建设道路及解决原则。  相似文献   

钢结构住宅体系墙板及墙板节点足尺模型振动台试验研究   总被引：5，自引：3，他引：5  

李国强  赵欣  孙飞飞  高文利  杨尊权  靳世文 《地震工程与工程振动》2003,23(1):64-70

本文对山东安尔发建筑科技有限公司开发的钢结构住宅体系的墙板及墙板节点足尺模型进行了模拟地震振动台试验研究，分析了该体系的自振特性、地震反应特征和破坏现象，特别对外墙板及内墙的节点的抗震性能进行了深入研究，得出了有益的结论，为钢结构住宅体系的进一步推广提供了试验依据。  相似文献   

异型柱框架结构抗震设计研究   总被引：1，自引：1，他引：1  

肖建庄  黄珏  李杰  张盛东 《地震工程与工程振动》2003,23(2):85-88

本文在充分考虑钢筋混凝土异型柱框架结构受力特点的基础上，从结构布置、内力组合与调整、轴压比限值和其他构造措施等方面，针对抗震计算和概念设计进行了分析与讨论，得出注重抗震计算分析、加强抗震概念设计等结论，分析过程和有关结论可供工程设计人员参考。  相似文献   

部分预应力混凝土扁梁框架节点的拟静力试验研究   总被引：4，自引：1，他引：4  

房贞政  李斌  郑则群 《地震工程与工程振动》2003,23(4):111-116

本文进行了四个部分预应力混凝土扁梁框架节点的拟静力试验研究。通过四个不同试件的试验研究分析了节点的变形能力、耗能能力、延性和刚度退化等抗震性能，同时分析了低周反复荷载作用下预应力混凝土框架节点的破坏机理。  相似文献