CHRIS／PROBA高光谱数据的预处理

针对CHRIS／PROBA高光谱遥感数据的特点,对CHRIS影像进行去条带处理、辐射校正、大气校正等预处理,获得较好质量的影像,为影像的进一步分析和实际应用提供保障。     

TM影像几何校正算法的精度比较

同大多数的线阵推扫式影像相比,TM影像作为双向扫描型的影像其几何校正方法有其特殊性和复杂性。针对这个问题,本文简要介绍了一般多项式、空间斜墨卡托投影、有理函数模型等几种几何近似校正算法,并利用广州地区的TM影像进行了各种试验分析和精度比较。结果表明:同其他方法相比,空间斜墨卡托投影是一种较好的算法,校正精度最高,能够达到一个像素左右,而且该方法不受地形起伏的影响,无需地面高程信息。     

Using Topological Relationships to Inform a Data Integration Process

When spatial datasets are overlaid, corresponding features do not always coincide. This may be a result of the datasets having differing quality characteristics, being captured at different scales or perhaps being in different projections or datums. Data integration methods have been developed to bring such datasets into alignment. Although these methods attempt to maintain topological relationships within each dataset, spatial relationships between features in different datasets are generally not considered. The preservation of inter‐dataset topology is a research area of considerable current interest. This research addresses the preservation of topology within a data integration process. It describes the functional models established to represent a number of spatial relationships as observation equations. These are used to provide additional information concerning the relative positions of features. Since many topological relationships are best modelled as inequalities, an algorithm is developed to accommodate such relationships. The method, based on least squares with inequalities (LSI), is tested on simulated and real datasets. Results are presented to illustrate the optimal positioning solutions determined using all of the available information. In addition, updated quality parameters are provided at the level of the individual coordinate, enabling communication of local variation in the resultant quality of the integrated datasets.     

附加约束条件的序贯平差

从观测量分组的参数平差出发,详细推导了附加约束条件的序贯平差及其精度估计,讨论了附加约束条件的抗差序贯平差的计算过程.算例表明,推导的公式正确有效,简单实用,附加约束条件的序贯平差抗差估计能有效地抵制粗差的影响.     

努力提高三维地震勘探精度，为西部煤炭工业做出新贡献

以国家重大产业技术开发专项“西部煤炭资源高精度三维地震勘探技术”项目的由来、意义和总体研究目标为引,概括的介绍了项目依托工程中各个专项技术研究完成情况,并对非均匀介质成像技术、高精度三维地震静校正技术、高密度采集技术、特观技术、岩性反演技术、属性体解释技术等六项重大关键技术取得的突破性进展进行了重点说明。指出随着我国煤炭生产重点的逐步西移,应加强诸如叠前、叠后深度偏移技术的研究,以解决复杂山区三维地震面元内地震反射波散射问题,提高其三维地震勘探精度,为西部煤炭工业做出新贡献!     

邢东矿井构造特征及应力应变场分析

邢东矿井位于太行山隆起带与华北沉陷带的过渡带,通过区域构造应力-应变场分析,本区先后经历了由挤压-拉张的变形过程,变形强度由弱到强。海西期构造应力影响较弱,印支期-中燕山期构造应力作用较为强烈,形成了大量的挤压结构面和压缩构造．燕山晚期-喜山期是构造形成的最终阶段,以拉张伸展变形为主,现今的多数正断层的断裂结构面仍保存有先期的挤压结构面特征。区内构造以断裂构造为主要形式,断层组合形式多样,这些构造形成期次不同,北西向断裂对北东向断裂具有限制作用。     

Long-term seismic noise investigations on Shikotan Island: First results

In 2003–2004, long-term seismic noise observations were launched on Shikotan Island (Lesser Kuril Range) based on the “Shikotan” dormant regional seismic station. The geological and geophysical data on the registration area are reported. Information about the equipment and its technical specifications is given. The precursors to the strongest local earthquakesthat occurred in the Shikotan Island region in January 2005–March 2007 are identified.     

Estimation of covariance matrix from geochemical data with observations below detection limits

Multivariate statistical analyses have been extensively applied to geochemical measurements to analyze and aid interpretation of the data. Estimation of the covariance matrix of multivariate observations is the first task in multivariate analysis. However, geochemical data for the rare elements, especially Ag, Au, and platinum-group elements, usually contain observations the below detection limits. In particular, Instrumental Neutron Activation Analysis (INAA) for the rare elements produces multilevel and possibly extremely high detection limits depending on the sample weight. Traditionally, in applying multivariate analysis to such incomplete data, the observations below detection limits are first substituted, for example, each observation below the detection limit is replaced by a certain percentage of that limit, and then the standard statistical computer packages or techniques are used to obtain the analysis of the data. If a number of samples with observations below detection limits is small, or the detection limits are relatively near zero, the results may be reasonable and most geological interpretations or conclusions are probably valid. In this paper, a new method is proposed to estimate the covariance matrix from a dataset containing observations below multilevel detection limits by using the marginal maximum likelihood estimation (MMLE) method. For each pair of variables, sayY andZ whose observations containing below detection limits, the proposed method consists of three steps: (i) for each variable separately obtaining the marginal MLE for the means and the variances, , , , and forY andZ: (ii) defining new variables by and and lettingA=C+D andB=C–D, and obtaining MLE for variances, and forA andB; (iii) estimating the correlation coefficient _YZ by and the covariance _YZ by . The procedure is illustrated by using a precious metal geochemical data set from the Fox River Sill, Manitoba, Canada.     

随钻测录井地质导向二维分解实时绘图方法

根据随钻测录井实时地质导向和大斜度、水平井评价成图技术需求，针对传统绘图方法存在的弊端，提出了将测录井信息、井眼轨迹和地质模型进行二维分解的实时绘图方法。针对二维分解绘图方法绘图时空复杂度较高的问题，给出了不同事件驱动下的局部实时计算和拷屏重绘算法，控制了对CPU和内存的消耗、提高了绘图效率，消除了实时绘图的闪烁和卡顿现象。应用实例表明，二维分解实时绘图方法能够实现大尺度随钻测录井地质导向图形的流畅、无卡顿实时绘图，可提高大斜度、水平井储层模型评价的刻画精度和时效。     

Analysis of COMPTEL gamma-ray burst locations and spectra

In its first three years of operation, the COMPTEL instrument on theCompton Gamma-Ray Observatory has measured the locations (mean accuracy 1°) and spectra (0.75-30 MeV) of 18 gamma-ray bursts and continues to observe new events at a rate of 1/month. With good angular resolution and sensitivity at MeV energies, the growing COMPTEL burst catalog is an important new piece of evidence in the on-going GRB mystery. The COMPTEL burst locations are consistent with an isotropic distribution of sources, yet the spatial coincidence of two of the bursts indicates the possibility of repetition. The COMPTEL burst spectra are in most cases consistent with a single power law model with spectral index in the range 2–3. However, two bursts show evidence of a spectral break in the MeV range. Measurement of rapid variability at MeV energies in the stronger bursts provides evidence that either the sources are nearby (within the Galaxy) or the gamma-ray emission is relativistically beamed. We present an overview of analysis results obtained from the COMPTEL burst catalog concentrating on the search for burst repetition and the implications of highly variable MeV emission.