空中重力异常代表误差在空域和频域的比较分析

在空域,利用严密的向上延拓公式将地面重力数据上延至空中不同高度,而后与相应的地面重力数据比较从而得到不同高度的代表误差.在频域,构建了新的代表误差模型,计算了不同高度、不同分辨率下的代表误差.实际算例表明,在空域,对于地形平坦区域,在1 km高度以下,5'空中重力数据直接代表地面重力数据的误差小于1×10-5 m/s2...     

GPS导航中的抗差自适应Kalman滤波算法

GPS导航与定位的质量取决于对动态载体函数模型和随机模型的认知。本文首先基于机动载体的当前统计模型 ,设计了离散系统的Kalman滤波器 ,进而基于方差分量估计给出了一种适合GPS动态定位的抗差自适应卡尔曼滤波算法。该算法模型简单 ,实时性好。实测数据计算结果表明 ,滤波导航解能有效地控制观测异常和动态扰动异常对导航解的影响 ,使导航解更能反映导航目标的真实情况     

The updated kriging variance and optimal sample design

A number of criteria based on kriging variance calculations may be used for infill sampling design in geologic site characterization. Searching for the best new sample locations from a set of candidate locations can result in excessive computation time if these criteria and the naive rekriging are used. The relative updated kriging estimate and variance for universal kriging estimation are demonstrated as a simple kriging estimate and variance, respectively. The updated kriging variance is demonstrated as the multiplication of two kriging variances. Using these updated kriging variance equations can increase the computational speed for selecting the best new sample locations. The application results for oil rock thickness in an oilfield indicate that minimizing the average relative updated kriging variance is a useful alternative to the other criteria based on kriging variance in optimal infill sampling design for geologic site characterization.     

The impact of the Laacher See Tephra on terrestrial and aquatic ecosystems in the Black Forest,southern germany

Late-glacial lake sediments containing the Laacher See Tephra (LST, 11000 yr BP) have been analysed for pollen and diatoms at two sites (Hirschenmoor, Rotmeer) in the montane belt of the Black Forest (southern Germany) in order to detect the possible impact of this major volcanic eruption on terrestrial and aquatic biota. The pollen assemblages at both sites show a minor increase in grasses and sedges following the tephra deposition, whereas the pollen of aquatic macrophytes do not show any consistent pattern. Partial redundancy analysis and Monte Carlo permutation tests suggest, however, that the LST had no statistically significant effect either on the terrestrial or aquatic pollen assemblages at either site when the effects of time and climatic change are allowed for statistically. The diatom assemblages at both sites changed after the deposition of the LST and diatominferred pH estimates suggest a short but non-significant excursion towards lower values. Multivariate analyses of the diatom data indicate a statistically significant impact of the deposition of the LST and associated changes in sediment lithology on the diatom assemblages when the effects of climatic change and time are allowed for statistically. However, owing to the interaction between tephra and lithology it is not possible to conclude if the diatom changes were caused by the deposition of the LST or by lithological changes.     

REVIEWS OF GEOGRAPHIC SOFTWARE

Reviews of geographic software in this article: ADD A STAT, Version 2.0 MULTIFIT, Version 2.0 CITY AND COUNTY DATA BOOK, 1983 Files on Diskettes. FUTPOP. CPSS/PC, Version 2. SOURCE ZIP and SOURCE TRACT STATPLAN 111 ySTAT.     

Solutions to the stochastic transport problem of O(σ V N ) for conservative solutes

A recursive perturbation solution to the eulerian transport problem for a conservative solute in a random conductivity field is reported. The stochastic concentration is given to arbitrary order inσ _ν, the variance of fluctuating velocity. The result gives the stochastic concentration as a perturbation to the deterministic concentration for constant mean flow. The closed form solution is easy to implement numerically via FFT.     

导线网方差分量估计的综合研究

提出方差分量估计的多余观测分量平均匹配方式；总结出导线网方差分量估计定权的基本规律，并给出其权增量循环算法和特征根法以及将两个实对称矩阵同时对角化的实用方法。     

方差分量非负二次估计可容许性的一个必要条件

本文讨论了方差分量线性模型中方差分量线性和∑Ｎｉ＝１ｃｉσ２ｉ估计量的可容许性，将文献［１］、［２］中Ｎ＝１的结果推广到多个情形，得到了一个必要条件