TEM法斜坡函数断电效应的修正及正反演计算

介绍了层状大地上水平共平面共心线框在阶跃函数或矩形脉冲激发时使用Gaver-Stehfest算法计算互阻抗的方法以及斜坡函数断电效应的修正、给出了重叠回线装置时全时域视电阻率的计算方法和TEM资料的反演算法。      

Holocene sea level trend on the west coast of Bohai Bay,China: reanalysis and standardization

Using 110 newly revised Holocene sea level indicators categorized into three types, sediments (67), shelly cheniers (27) and oyster reefs (16), this paper firstly provides a Holocene relative sea level curve, based on multiple approaches of litho- and biostratigraphies and sedimentary faces analysis, for the west coast of Bohai Bay, China. Following considerations, including indicative meaning, the paleo tidal pattern and range and conversion from mean tidal level to mean sea level, an apparent relative mean sea level (RMSL) curve was further reconstructed. After systematical calibration using CALIB, those of the 48 reworked samples were further corrected for the residence-time effect. Similarly, the younger ages for another 35 samples were chosen at the subsample level. These result in a younger-oriented shift for about 0.5 ka. Three local spatial factors, including neotectonic subsidence (average rate about 0.1 mm/a), self-compaction of unconsolidated sediments (between a few decimeters to about 6 m) and subsidence due to groundwater withdrawal (between a few centimeters to about 2.5 m), were quantitatively corrected. Finally, the amended RMSL curve after eliminating all these local temporo-spatial factors is very likely to show non-existence of mid-Holocene highstand and imply potential influences of both ice-volume equivalent sea level and regional glacial isostatic adjustment. Although it is still unable to divide both global and regional factors, the slowdown of sea level rise, in 7.5–6.8 ka with a maximum height less than +1 m, may constrain the model effort in the near future.     

海量管线数据库动态更新融合技术的探讨与应用

随着全国管线数据普查的大范围开展,海量管线数据库建立。海量管线数据库的更新制约着城市地下管线数据的有效利用和城市的发展。本文介绍了海量管线数据库动态更新融合技术,阐述了管线数据动态更新的技术方法,并介绍了该技术的优势和应用效果。     

基于VB平台桥网间接平差的设计与实现

本文采用间接平差方法,利用VB语言,结合高校教学项目,设计编程了一套基于VB平台的间接平差方法软件,运行解算桥网未知控制点的坐标平差值及高程平差值,并解算其点位精度。结果表明,点位精度不超过3 mm,误差改正数不超过2 mm,解算精度较高,符合要求。由此说明了利用间接平差方法解算桥网的正确性及可行性,并将其运用到高校平差解算其他平面控制网。     

一种基于变分优化的逐步订正法在海冰密集度分析中的应用

卫星遥感获取的海冰密集度观测资料中包含着空间多尺度信息。然而,多数传统的数据同化方法难以在海冰密集度变化较为复杂的海冰边缘区有效提取这些多尺度信息。为解决上述问题,本文设计了一种基于变分优化的逐步订正分析方法—空间多尺度递归滤波,该方法是逐步订正分析与最小化算法的结合,它能够从长波到短波依次提取观测中的各种空间尺度信息。与传统的客观分析相比,这种基于变分的多尺度分析方法不仅能够在最小化过程中一次性的提取出观测中的多尺度信息,而且能够方便合理的进行参数配置。单观测点同化试验的分析结果表明,空间多尺度递归滤波方法具有良好的观测信息空间传播能力。随后在二维海冰密集度的分析试验中,该方法能够较好的提取SSMI海冰密集度观测资料中的空间多尺度信息,进而获得高精度的海冰密集度分析结果。     

On Frequency Response Corrections for Eddy Covariance Flux Measurements

Several potentially significant errors are noted in published frequency-response corrections for eddy-covariance flux measurements.     

高度计大气湿度校正的方法及其应用分析

大气中水汽造成的路径延迟的测量误差是目前卫星高度计存在误差的重要原因,这种误差对高度计数据的分析应用产生很大的影响.介绍了高度计大气湿度校正的2种方法,并对它们的结果做了比较.最后分析了大气湿度校正对高度计数据应用的影响.     

An Experiment on the Prediction of the Surface Wind Speed in Chongli Based on the WRF Model: Evaluation and Calibration

In this study,the ability of the Weather Research and Forecasting(WRF)model to generate accurate near-surface wind speed forecasts at kilometer-to subkilometer-scale resolution along race tracks(RTs)in Chongli during the wintertime is evaluated.The performance of two postprocessing methods,including the decaying-averaging(DA)and analogy-based(AN)methods,is tested to calibrate the near-surface wind speed forecasts.It is found that great uncertainties exist in the model’s raw forecasts of the near-surface wind speed in Chongli.Improvement of the forecast accuracy due to refinement of the horizontal resolution from kilometer to subkilometer scale is limited and not systematic.The RT sites tend to have large bias and centered root mean square error(CRMSE)values and also exhibit notable underestimation of high-wind speeds,notable overestimation or underestimation of the near-surface wind speed at high altitudes,and notable underestimation during daytime.These problems are not resolved by increasing the horizontal resolution and are even exacerbated,which leads to great challenges in the accurate forecasting of the near-surface wind speed in the competition areas in Chongli.The application of postprocessing methods can greatly improve the forecast accuracy of near-surface wind speed.Both methods used in this study have comparable abilities in reducing the(positive or negative)bias,while the AN method is also capable of decreasing the random error reflected by CRMSE.In particular,the large biases for high-wind speeds,wind speeds at high-altitude stations,and wind speeds during the daytime at RT stations can be evidently reduced.     

广义线性反演初至折射静校技术在金属矿区的应用

在复杂地表地区,近地表速度构造模型的确定在地震资料处理和成像过程中是一个至关重要的工作.针对传统方法只能解决静校正中的部分问题,精度不高,本文采用的广义线性反演折射法,利用初至时间对大量数据进行统计,用交互、迭代的方法计算静校正量.该法在土屋斑岩铜矿区的应用,表明在提高信噪比方面比较传统方法有明显的提高.