基于CHAMP卫星与三维Taylor多项式模型的区域地磁建模研究

利用CHAMP卫星矢量和标量地磁测量数据,通过三维Taylor多项式模型建立了2010.0年中国及邻近地区在300km高度附近的X、Y、Z和F分量的三维磁场模型.为了比较验证所建模型,分析了其与Taylor多项式模型(二维模型)不同截断阶数所对应的均方偏差(RMSE)、残差及分布等.结果表明,三维模型每一阶的RMSE和残差绝对值的平均值均要比二维模型的小约45%.由于采用了系数完全展开的建模方式,三维模型的系数数量约为二维模型的2倍,三维模型较低的截断阶数可以反映更多的地磁信息.本研究中的5阶三维Taylor模型基本可达到8阶Taylor模型的精度.两种模型绘制的地磁场及残差分布有较好的一致性.     

几种卫星钟差预报模型预报效果的分析与比较

采用GPS精密钟差数据进行预报试验,对二次多项式模型、谱分析模型、GM(1,1)模型、ARIMA模型以及Kalman滤波模型5种模型的钟差预报效果进行分析和比较,总结了各模型预报钟差的优点与不足,并对GPS系统目前运行的6种星载原子钟的预报特性进行简单分析。     

京沪高速铁路沉降趋势分析与预报方法的研究

分别运用多项式拟合和灰色GM(1,1)模型,对京沪高速铁路常州段桥墩沉降监测数据进行了处理与分析,验证了灰色GM(1,1)模型的预测效果优于多项式拟合,能较好地预测桥墩的沉降趋势。     

基于ITRF2005基准下的速度场融合分析中国大陆板块运动趋势

利用GPS观测资料研究地球动力学问题是目前地学中研究的热点,数据融合也是大地测量研究中的一个重点。主要利用已公开发表的GPS速度场结果,结合上述两点分析中国大陆各个块体板块运动趋势,得出的结果与现今研究成果具有一致性。     

基于抗差Chebyshev多项式的相位伪距周跳探测与修复算法

相位伪距组合(1,-1)受多路径变化和电离层延迟的影响,周跳探测精度为2周,严重影响了传统相位伪距法的周跳探测性能。针对这一问题,利用基于抗差估计的Chebyshev多项式对各备选周跳的观测值进行拟合,依据残差和最小的原则,准确判别出原始相位的周跳值。实例验证该方法实用性强,可靠性高,相比传统相位伪距法具有更好的周跳探测与修复能力。     

切比雪夫多项式在模式地形平滑中的应用研究

利用切比雪夫多项式展开滤波方法获得较为平滑的模式地形,并对2008年7月20～22日四川省一次大暴雨过程进行了数值模拟,通过地形敏感性试验讨论了地形对暴雨的影响作用以及平滑地形对GRAPES模式的适用性。结果表明,切比雪夫多项式展开滤波方案选取高阶截断项数,促使模式地形更为平滑,地形高度变化使得垂直速度发生变化,进而引起降水变化,上升运动强度增强(或减弱)引起该区域内雨强增强(或减弱)。2008年7月2～28日连续26天的试验表明,切比雪夫多项式展开滤波方案对GRAPES模式中的小雨和中雨预报有改善作用,对大雨和暴雨改善较小。总体来看,切比雪夫多项式在地形平滑中对降水预报有正的效果。     

嵌入式系统CRC循环冗余校验算法设计研究

介绍了CRC循环冗余校验基本原理及生成多项式表示,分别研究了嵌入式系统CRC-8-Dallas/Maxim与CRC-16-IBM生成多项式及其硬件描述.以DS18B20器件的ROMID/Scratchpad数据校验及Modbus总线网络数据帧校验为例,通过对生成多项式及硬件描述的分析研究得出了基本比特型校验算法设计,在数学推导的基础上得出了其改进的比特型校验算法及单字节、半字节查表校验算法.为获得更高的校验速度,提出了一种基于块及多表的校验算法,比较了几种校验算法的ROM空间占用与校验处理速度.所设计的CRC校验程序为嵌入式系统数据的可靠传输提供了重要保证.     

汶川8级大地震对川滇菱形区域内次级块体的运动影响分析

在中国境内所有的二级块体运动中,川滇区域的地壳运动最为活跃,也是各学者研究的热点领域。本文通过对1998-2008年和2008-2015年两期GNSS连续观测数据的解算（时间节点为汶川地震）,并结合前人对川滇区域棱形块体的划分方案,利用欧拉矢量计算出各次级块体的欧拉矢量。对该区域进行了网格插值从而反演两期地壳运动变化特征,以及通过在断裂带上或断裂带附近选取一点来研究相邻块体的相对运动趋势变化,并对该区域内地块垂向运动作了初步研究分析。结果表明,汶川地震并没有造成该区域整体运动特征的改变,但对一些局部块体的运动和相邻块体的相对运动带来了一定的影响。     

Água Bonita pull apart basin and its relationship to Transbrasiliano Lineament

The Transbrasiliano Lineament (TBL), a NE-SW trending strike slip system at least 2700 km long, is one of the main structures of the South American Platform. This lineament, along with other structures, influenced greatly the installation and depositional history of the Paraná and Parnaíba sedimentary basins. The Água Bonita Basin (ABB) occurs at an intermediate position between both basins. This work aims to provide information on the origin and evolution of the Água Bonita Basin, considered a Silurian-Devonian basin, as well as its relationship with the Transbrasiliano Lineament.Geological, aero and ground geophysics data were used to determine a structural geological model for the ABB located in the Brasilia Fold Belt in the Tocantins tectonic province. The airborne geophysical magnetic data used in the study were acquired in the 1970s by the existing 147 ground gravity stations in addition to the 498 new ground gravity and geodetic stations that were added to the existing ones.The analysis of the outcrops allowed identifying the sedimentary facies associations providing new information on the depositional environments. The compilation of existing data, satellite images analysis, geological maps and shaded relief provided an integrated model for the study area.A geological model was proposed for the ABB based on the interpretation, integration, depth analysis and 2D gravity forward modeling according to a theoretical model for an extensional duplex in a strike slip system with flower structures. We observed several segmented gravity anomalies, which were interpreted as steps/faults. This interpretation is consistent with a pull apart basin. According to the depth data estimated by this model, the maximum thickness of the Água Bonita Formation is 1.6 km and 2.4 km for the precursor rift. The basin has two dextral faults on each border, whose main fault of the TBL strike slip system and the master fault controlling the ABB are observed on the east border of the rift phase. Lineaments perpendicular to the west edge, in addition to those crossing the ABB in the N65E, delineate peculiar magnetic, gravity and geological signatures in the northern part of the basin. The basin is located in the weak region of the TBL and its main eastern fault is dipping sub-vertically to the west. This fault modeled up to the 8 km depth using the gravity data, was also observed in the Tilt Angle of the Total Horizontal Gradient (TAHG) matched filter grid result at approximately 8 km, however this may not be this fault maximum depth.Three main sedimentary-tectonic stages were observed, (i) a Pre-Devonian precursor rift present in the Água Bonita Basin and Jaibaras Group; (ii) the sag stage developed during the Devonian, when the Paleozoic basins of Paraná, Parnaíba and Água Bonita Basin were connected evidenced by the sedimentary facies and similar thicknesses; and (iii) the Pos-devonian rocks that are probably not preserved in the Água Bonita Basin.