Nonparametric Estimates of the Sea State Bias for the Jason-1 Radar Altimeter     

SYLVIE LABROUE  PHILIPPE GASPAR  JOEL DORANDEU  OZ ZANIFé  F. MERTZ  PATRICK VINCENT 《Marine Geodesy》2013,36(3-4):453-481

The Jason-1 sea state bias (SSB) is analyzed in depth from the first year of GDR products. Compared to previous missions, this work benefits from two aspects of the empirical determination of the SSB from the altimetric data themselves. First, from a methodological point of view, a nonparametric technique (NP) has been developed and largely tested on TOPEX/Poseidon 1, GFO and Envisat data. The NP estimator has proven to be a useful tool in the SSB estimation, and it is now mature enough to be used for a refined analysis. On the other hand, the SSB can be extracted from three different data sets (crossovers, collinear data, and residuals) with different characteristics. It is then possible to cross calibrate various estimations of the SSB models and to determine the most accurate one. A systematic comparison is made between these different estimates for the Jason-1 altimeter. The collinear and crossover data sets yield very similar estimates despite their difference of spatial and temporal distributions. These SSB models assure consistency with the TOPEX mission when comparing Jason-1 and TOPEX residuals during the tandem phase. Thanks to the present work, the impact of the short wavelengths filtering on the SSB estimation is evidenced. More generally, our understanding of potential errors affecting the sea surface height and their impact onto the SSB estimation is also improved.  相似文献   

面向对象的基态修正模型改进及查询方法     

陆纳纳  李景文  苏浩  花维慧 《测绘科学技术学报》2012,(4):299-302

空间和属性随时间变化规律的研究是时态GIS核心问题。引入面向对象方法,把地理实体抽象成为具有空间、属性和时间特性的空间对象,以空间对象的变化状态为基础,探讨了地理实体时空信息连续变化对基态修正模型的影响。通过引入基态距影响因子研究了基态修正模型改进方法,重点研究了基于面向对象基态修正模型的基态距确定、基态的建立过程和模型的存储;并具体设计了基于时间点和时间段的查询方法,为空间对象的时空数据存储、查询和历史回溯提供了基础。  相似文献   

STATE PARKS AND JIM CROW IN THE DECADE BEFORE BROWN v. BOARD OF EDUCATION     

WILLIAM E. O'BRIEN 《Geographical review》2012,102(2):166-179

African Americans had access to only a small number of state parks in the Jim Crow South. Between the end of World War II and the U.S. Supreme Court's 1954 Brown v. Board of Education decision, however, state park officials oversaw a relative expansion in the construction of facilities available to southern blacks. Emphasizing developments leading up to that landmark court ruling, I note that this trend did not indicate waning support for segregation among whites. Rather, this relative expansion was part of a strategy to protect Jim Crow by demonstrating that the “separate‐but‐equal” principle was being successfully achieved by southern park agencies. This intensified construction was largely a reaction to increasingly successful legal action in federal courts by the naacp generally; and officials in the state agencies hoped—unsuccessfully—to avoid challenges to state park segregation. After the Brown decision, several border states integrated their park systems, but most agencies displayed the reactionary defiance that characterized most white Southerners as the civil rights movement grew.  相似文献   

Scalar politics and strategic consolidation: The Norwegian Gas Forum's quest for embedding Norwegian gas resources in domestic space     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):226-237

Underthun, A., Kasa, S. & Reitan, M. 2011. Scalar politics and strategic consolidation: The Norwegian Gas Forum's quest for embedding Norwegian gas resources in domestic space. Norsk Geografisk Tidsskrift–Norwegian Journal of Geography Vol. 65, 226–237. ISSN 0029-1951.

The article discusses political initiatives and networks that aim to enhance the use of Norwegian natural gas resources in domestic space. Through perspectives on state rescaling and scalar politics, the authors explore the strategies of the Norwegian Gas Forum (NGF). This political network serves as an umbrella organization for regional political initiatives for local distribution and exploitation of natural gas along the Norwegian coast. It is argued that the initiatives demonstrate a scalar politics that counter tendencies of state rescaling in the realm of petroleum politics, where the state is less willing to invest and intervene in domestic natural gas utilization. The article examines the NGF's policy work, organizational composition, and ‘networks of association’ with other organizations. This is framed in the analysis as ‘scalar politics’ aiming to secure the member regions’ current and future dependence on domestic gas supplies. The important networks of association in relation to the Norwegian Confederation of Trade Unions (LO) and the Confederation of Norwegian Enterprise (NHO) implied compromise and consolidation among the regional members of NGF, but also empowered NGF on important policy issues.  相似文献   

香港入境旅游客源市场竞争态与亲景度研究   总被引：1，自引：0，他引：1  

郭安禧  黄福才 《地域研究与开发》2012,31(1):104-109

以2006年为界将2004-2009年划分为前后两个时期,对比分析发现,香港入境旅游客源市场主要集聚在幼童市场和瘦狗市场,分布于明星市场和金牛市场的很少.市场竞争态转移表现为幼童市场向瘦狗市场回落,金牛市场朝瘦狗市场退缩.市场竞争态呈现逐渐衰退的迹象.亲景度除韩国和澳门外,其余主要客源市场均属于亲景市场,在空间上变动相对平稳,在时间上均值降幅不大.将竞争态与亲景度进行联合分析,显示亲景度与市场占有率的相关性更大,据此可将入境旅游客源市场聚为4类.  相似文献   

上海世博园风廓线雷达TWP3发射机控制系统设计与实现     

张垚  尹春光  刘强 《气象科技》2012,40(1):15-19

介绍坐落在上海世博园内TWP3边界层风廓线雷达系统发射机控制系统设计思路及其功能特点。控制系统基于FPGA和单片机的程序控制实现手段。系统功能包括状态监控、射频通路控制、故障诊断定位、自动保护和自修复。发射机的各个监控量会在本机液晶屏幕显示以便用户的使用和观察,同时将重要的参数上传等。该控制系统自身监控功能的完善,对于发射机本身的调试以及在整个雷达系统的联合调试测量中都起到了至关重要的辅助作用。  相似文献   

Wellbore breakouts of the main borehole of Chinese Continental Scientific Drilling (CCSD) and determination of the present tectonic stress state     

Jun-wen Cui  Pengwu Li  Dong-sheng Sun 《Tectonophysics》2009,475(2):220-203

The Sulu-Dabie high-pressure (HP)-ultrahigh-pressure (UHP) metamorphic belt as the product of subduction-collision between the northern China plate and Yangtze plate underwent a process of formation and evolution from deep subduction→exhumation→extension→slow uplift. The study of its modern tectonic stress field has great significance for a complete understanding of the process of formation and evolution of the HP-UHP metamorphic belt, especially the exhumation and uplift of the belt. Wellbore breakouts are the most visual tectonic phenomenon which can characterize the modern stress action in the main borehole of Chinese Continental Scientific Drilling (CCSD). Ultrasonic borehole televiewer reflection wave data show that wellbore breakouts began to occur at 1216 m depth of the main borehole. A total of 143 borehole televiewer images were collected from 1216 to 5118 m depth (hole completion depth). After data processing and statistics, the average azimuth of the long dimension of the wellbore breakout obtained was 319.5° ± 3.5°, indicating that the average azimuth of the maximum horizontal principal stress causing wellbore breakout initiation was 49.5° ± 3.5°. The maximum and minimum horizontal principal stress values at 52 depths in the interval of 1269 to 5047 m were estimated using the elements of wellbore shapes (wellbore depth and width), combined with the cohesive strength and internal frictional angle of the rock obtained by rock mechanical tests on samples, and the static load stresses at corresponding depths were calculated according to the rock density logging data. The results indicate that: the maximum and minimum horizontal principal stresses are 41.4 and 25.3 MPa at 1269 m depth respectively and 164.7 and 122 MPa at 5047 m depth respectively; the maximum vertical stress is 141.3 MPa at 5047 m depth with a density of 2.8 g/cm³; the in-situ stresses increase nearly linearly with depth. The magnitudes and directions of the three principal stresses reflect that the regional stress field around the CCSD main borehole is mainly in a strike-slip state, which is consistent with the basic features of the regional stress field determined using other methods.  相似文献   

大洋锰结核中钴的赋存状态及提取实验研究     

于德利  张培萍  肖国拾  张东丽 《吉林大学学报(地球科学版)》2009,39(5)

为合理有效地提取和利用大洋金属资源,在对大洋锰结核化学成分及矿物组成进行测定的基础上,采用分布溶解法对钴的赋存状态进行了分析.选择还原氨浸法对大洋锰结核中的多金属进行了浸取实验,并用铵黄铁矾法对浸取液进行了除铁及用硫化沉淀法对钴进行分离提取等实验.结果表明:大洋锰结核中钴的质量分数可达0.30%,且主要以硅酸钴、氧化钴和硫化钴的形式存在.氨浸提取可以有效地使金属离子从结核中溶出,其中钴的浸出率最高可达93.25%;铵黄铁矾法可将浸出液中的铁全部去除.提取的硫化钴中除含有少量铬外未见其它杂质元素.  相似文献   

地球内部极端条件下流体和物质相互作用:透过金刚石窗口探测地球深部流体   总被引：2，自引：1，他引：1       下载免费PDF全文

张荣华  张雪彤  胡书敏 《地学前缘》2009,16(1):41

报道关于地球内部极端条件下的流体实验研究的最新进展。使用金刚石压砧结合各种谱学方法及同步辐射光源技术,在高温超高压条件下原位直接测量物质的结构和性质,已经获得分子-原子尺度信息新的实验数据。本项工作使用金刚石压砧对高压(10GPa)和高温高压(800℃,3GPa)条件下的NaCl-H2O进行红外谱原位直测,研究了高压和高温高压下水分子结构,发现水分子的O—H振动特征峰频率随温度向高波数变化,而且,在临界态区域时水分子间的氢键网格被破坏。实验说明:地球内部流体性质由深到浅不断变化,如水的密度、介电常数等物理参数随温度压力而改变,在临界态出现突变。这些变化可以用高压高温的物质的各种谱学特征来表征。水的性质与它的分子结构、分子振动有关。在跨越临界区时水的性质异常涨落是由水分子结构异常变化、分子振动形式变化和氢键网格破坏所导致的。从分子尺度认识地球内部流体在极端条件下的性质和高压原位实验观测有助于我们进一步了解地球深部物质的性质及其相互作用,有助于认识深部过程。  相似文献   

河南商城汤家坪钼矿成矿地质特征与构造解析     

李悦辉  王季伟 《华南地质与矿产》2009,(4):37-42

本文通过工程勘查资料及岩石化学特征分析,从构造-岩浆-流体系统来解析汤家坪钼矿的成矿地质特征,为相似地质条件下的深部找矿提供思路。研究表明,早白垩世,在大别造山带核部,陆内张性构造环境中,沿深大断裂的岩浆上侵,成就了具有明显成矿地质特征的汤家坪钼矿：穹隆状容矿空间——矿体岩体内矿化元素呈晕律层状分布。  相似文献