松辽盆地南部深层地震资料处理方法研究     

李振江  赵奎  杨秋莹  李春雨  张术权 《世界地质》2004,23(2):179-182,186

针对松辽盆地南部深层原始地震记录接收能量弱、信噪比低、各种干扰波严重和地表条件多变等存在严重的静校正问题，尝试利用CGG、Foucs、Grisys、Promax等多套处理系统的优势模块对跨工区二维大吾4面进行深部地层的折射波静校正、反褶积、剩余静校正、DipMoveOut、偏移等关键技术的联合处理方法试验研究，形成了一套针对松辽盆地南部深层地震资料处理的有效方法。  相似文献   

Analysis of Sediments and Soils by X-Ray Fluorescence Spectrometry Using Matrix Corrections Based on Fundamental Parameters   总被引：2，自引：0，他引：2  

Jacinta Enzweiler  Maria Aparecida Vendemiatto 《Geostandards and Geoanalytical Research》2004,28(1):103-112

Wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) is widely used for the analysis of soils and sediments using well characterised procedures. However, difficulties can occur with samples such as unknowns containing small amounts of ore materials and samples collected from contaminated sites where trace elemental concentrations can exceed the concentration range for routine analysis. We studied the performance of a commercially available method, based on fundamental parameters (FP) to correct matrix effects. The spectrometer was originally calibrated with elemental or simple compound calibrants. Samples were analysed as pressed powder pellets. Eighteen sediment and soil reference materials, three of them with certified values for some of their constituents, were used to evaluate accuracy, by comparing results with recommended values and their standard deviations (RV ± 2s) or certified values and their confidence intervals (CV ± Cl). When results fell systematically outside these intervals, calibrations were refined with geochemical reference materials. The best agreement of results with recommended and certified values was obtained when the contents of H₂O and C in each sample were included as matrix constituents during calculations. The detection limits of trace elements tended to be relatively high, because the measuring conditions employed were not maximised for sensitivity. The main advantage of the method tested was that it enabled the analysis of samples with high concentrations of trace elements and the determination of elements such as F, Bi, Sb and W, which are not commonly included in quantitative XRF analysis of geological samples.  相似文献   

基于EM算法和单幅雷达图像阴影的控制点坡度校正   总被引：1，自引：0，他引：1  

钱俊  舒宁 《武汉大学学报(信息科学版)》2004,29(12):1089-1092

对在我国现有的条件下进行控制点坡度校正的必要性进行了阐述，并分析了EM算法。根据EM算法以及基于区域增长的余弦散射模型建立了控制点坡度校正模型，并用河北省张北地区的雷达影像进行了实验，取得了较高的精度初值。  相似文献   

MODIS 1B影像几何纠正方法研究及软件实现   总被引：24，自引：0，他引：24  

蒋耿明  刘容高  牛铮  庄大方 《遥感学报》2004,8(2):158-164

MODIS影像是一种新型和重要的数据。对MODIS 1B影像几何畸变原因进行了深入分析，选择了一种合适的纠正方法。对于1km分辨率MODIS 1B影像，直接采用1km分辨率的空间坐标进行几何纠正；对于250m和500m分辨率的MODIS 1B影像，先用三次样条曲线对坐标进行插值生成同分辨率的坐标，然后利用坐标插值结果对其进行几何纠正。由于MODIS影像在空问分布上的特殊性，采用前向和后向映射相结合的方式确定纠正后某一像素点在原始影像中的位置。根据该位置的条带重叠度，可以确定参与计算像素个数、搜索窗口的大小以及窗口的精确位置；采用归一化反距离加权插值法计算纠正后像素点的属性值。上述优化算法不仅保证了纠正后影像的质量，而且提高了数据处理速度。作者在Visual C 6．0环境下开发实现了上述算法。从坐标插值和几何纠正结果分析，无论是数据处理速度还是纠正后的影像质量和精度均达到要求。  相似文献   

水下地形测量高程异常点剔除方法研究   总被引：2，自引：0，他引：2  

王红  邸国辉熊燕 《四川测绘》2004,27(1):36-38

本文针对水下地形测量过程中测深数据的粗差问题，结合在生产工作中的一些经验和有关的资料，提出了测深数据处理的方法，并编写了相应的程序用于生产。  相似文献   

锦州地震台体积式钻孔应变仪的映震情况     

明成山  李京锦  李哲 《地震地磁观测与研究》2005,(Z1)

论述了张北MS6.2、沈阳ML4.1、内蒙古ML5.9、日本北海道MS8.0、俄蒙中交界MS7.9、青海昆仑山MS8.1地震前后,锦州地震台体积式钻孔应变仪观测震前异常的变化规律。通过计算潮汐因子、振幅因子、3点线性平滑滤波残差值等方法,识别异常。结果表明,体应变异常资料与地震有一定的相关性。  相似文献   

Correcting method of eddy covariance fluxes over non-flat surfaces and its application in ChinaFLUX     

ZHU Zhilin  SUN Xiaomin  ZHOU Yanlian  Xu Jinping  YUAN Guofu  ZHANG Renhua 《中国科学D辑(英文版)》2005,48(Z1)

Although Eddy Covariance (EC) technique is one of the best methods for estimating the energy and mass exchanges between underlying surface and atmosphere in micrometeorology, errors and uncertainties still exist without necessary corrections. In this paper, we will focus on the effect of coordinate system on the eddy fluxes. Based on the data observed over four sites (one farmland site, one grassland site and two forest sites), the effects of three coordinate system transforming methods (Double Rotation-DR, Triple Rotation-TR and Planar Fit-PF)on the turbulent fluxes are analyzed. It shows that (i) the corrected fluxes are more or less than the uncorrected fluxes, which is related mainly to the sloping degree of surface, wind speed and wind direction; and (ii) pitch angle has a sinusoidal dependence on wind direction, especially in the regular sloping terrain; and (iii) PF method is something like the simplification of TR or DR,and there are not obvious distinctions in correction in sloping grassland and flat farmland, but PF method is not suitable for uneven and irregular forest sites.  相似文献   

Using raw regional climate model outputs for quantifying climate change impacts on hydrology          下载免费PDF全文

Jie Chen  François P. Brissette  Pan Liu  Jun Xia 《水文研究》2017,31(24):4398-4413

General circulation model outputs are rarely used directly for quantifying climate change impacts on hydrology, due to their coarse resolution and inherent bias. Bias correction methods are usually applied to correct the statistical deviations of climate model outputs from the observed data. However, the use of bias correction methods for impact studies is often disputable, due to the lack of physical basis and the bias nonstationarity of climate model outputs. With the improvement in model resolution and reliability, it is now possible to investigate the direct use of regional climate model (RCM) outputs for impact studies. This study proposes an approach to use RCM simulations directly for quantifying the hydrological impacts of climate change over North America. With this method, a hydrological model (HSAMI) is specifically calibrated using the RCM simulations at the recent past period. The change in hydrological regimes for a future period (2041–2065) over the reference (1971–1995), simulated using bias‐corrected and nonbias‐corrected simulations, is compared using mean flow, spring high flow, and summer–autumn low flow as indicators. Three RCMs driven by three different general circulation models are used to investigate the uncertainty of hydrological simulations associated with the choice of a bias‐corrected or nonbias‐corrected RCM simulation. The results indicate that the uncertainty envelope is generally watershed and indicator dependent. It is difficult to draw a firm conclusion about whether one method is better than the other. In other words, the bias correction method could bring further uncertainty to future hydrological simulations, in addition to uncertainty related to the choice of a bias correction method. This implies that the nonbias‐corrected results should be provided to end users along with the bias‐corrected ones, along with a detailed explanation of the bias correction procedure. This information would be especially helpful to assist end users in making the most informed decisions.  相似文献   

北斗系统周跳探测与修复方法探究     

李彬 《测绘与空间地理信息》2016,(8):160-165

北斗卫星导航系统是中国自行研制的继美国GPS和俄罗斯GLONASS之后第3个成熟的卫星导航系统。进行GNSS相位数据处理的过程中,由于某种原因,载波相位观测值突然出现整周数的跳变的现象称为周跳。周跳现象的发生将会严重影响后续的数据处理,因此,有必要在解算前完成周跳探测与修复工作。本文就北斗系统周跳探测与修复课题进行了较为全面的探究,先后介绍了高次差法、多普勒法、伪距载波相位组合法、电离层残差法、三频数据组合探测法等一系列周跳探测与修复方法,可分别应用于不同频段接收机、不同观测环境、不同数据处理模式。  相似文献   

高速铁路桥墩偏移整治工程线上监测及结果分析     

张冀辉  王涛 《测绘与空间地理信息》2016,(6)

高速铁路建成运营后,受外部因素的影响,如在桥墩一侧施工、堆载等,会造成桥墩发生偏移,影响线路的平顺性,严重威胁高速铁路行车安全,需对其进行纠偏整治。本文以某城际高铁K19段高架桥桥墩的偏移整治工程为例,在整治期间,对线上监测点和轨道线形监测,根据监测结果指导施工,直至达到纠偏目标。监测结果表明了监测方案的有效性、正确性,能够对施工起到较好的指导作用,且能够为纠偏是否达到目标提供可靠的判断依据。可为类似高速铁路的纠偏整治及线上监测提供良好的参考。  相似文献