基于光学遥感影像的2019年加利福尼亚MW7.1和MW6.4双震同震形变测量

利用地震前后的Landsat-8和Sentinel-2光学遥感影像数据,基于频率域互相关算法提取加利福尼亚州MW7.1及MW6.4地震的同震形变场,同时针对形变数据易受轨道误差、条带误差及时间失相干的影响,分别采用最小二乘多项式曲线拟合、改进均值相减等方法去除系统误差项。研究表明,MW7.1主震以右旋走滑为主,地表形变的断层迹线呈NNW走向,长度达55 km,最大滑移量约为2.82 m;MW6.4地震的发震断层迹线呈NE走向,长度达15 km,最大滑移量约为1.05 m,推测2次地震的发震断层分别为NNW向右旋走滑断裂及NE向左旋走滑断裂,二者形成典型的共轭关系。     

青藏高原东南缘现今地壳形变与多尺度应变率场特征

利用青藏高原东南缘1999~2007年与2011~2017年高精度GNSS监测资料,充分顾及GNSS测站非均匀分布的特性,构建青藏高原东南缘地壳形变多尺度球面小波模型,定量分析汶川强震前后该区域地壳形变与不同空间尺度下地壳应变率场变化特征。研究结果表明,汶川强震前后研究区整体地壳运动具有一定继承性发展特征,均在龙门山、安宁河、则木河与小江断裂处形成明显的速度差异梯度带,且高应变率值也主要聚集在上述主干断裂及附近区域;汶川强震后,研究区域整体地壳运动速率量值,特别是龙门山断裂带西北侧地壳运动速度量值显著增大,羌塘、巴颜喀拉与川滇地块也呈现出加速向南东运移并推动华南块体的趋势。不同尺度下的应变率场反映出不同空间范围下区域应变积累特征,青藏高原东南缘区域在尺度因子q=7时的计算结果是合理的（合理的最大尺度因子）;当尺度因子q=6时,能较好地揭示出区域整体构造活动特性,即清晰地揭示出汶川强震后龙门山断裂处呈现出的显著主压应变、面压缩与最大剪应变率高值特征;当尺度因子q=3~7时（最佳组合尺度因子）,可较好地综合揭示出区域地壳大尺度（整体）形变与局部形变特征。汶川强震后,研究区域主干断裂带,特别是震中及其附近区域地震活动性显著增强。     

豫西南泥湖地区辉长岩地球化学特征及其与成矿关系

豫西南泥湖钼矿集区是以花岗斑岩体为中心的钼多金属矿床系列,区内出露大面积加里东期变辉长岩和燕山期辉长岩。通过分析区内辉长岩的岩石学、年代学、地球化学和成矿元素等方面特征,研究其在成岩成矿过程中的作用。区内加里东期变辉长岩和燕山期辉长岩成矿元素总稀土含量低,稀土元素球粒陨石标准化曲线右倾平缓,具有明显的Eu,Tm元素的异常;同比世界基性岩,自晚元古代上地幔主要成矿元素(除钨元素以外)基本没有明显的富集,主成矿元素钼含量呈明显的亏损,预示燕山期成矿花岗质岩浆没有从上地幔获得主要成矿物质。初步认为大规模的钼多金属成矿带的形成与基性岩浆的底垫作用相关,基性岩浆的底垫作用为下地壳部分熔融形成岩浆房提供了热源。     

山东龙口市大磨曲家金矿地质特征及找矿方向探讨

大磨曲家金矿位于玲珑金矿田东风矿床主脉的NE延伸部位.矿区内已发现矿脉25条.通过对玲珑金矿田的成矿条件分析和东风矿床的综合研究,认为本区有很好的找矿前景.     

用曲面插值方法建立海洋局部地磁场模型

地磁场模型是地磁场的数学表达式,国内外已有多种建立地磁场模型的方法,对于局部地磁场模型来说,应用比较多的是多项式方法和曲面样条函数方法。讨论了基于曲面样条函数建立局部地磁场模型的原理和方法,并在实测数据基础上对模型的精度进行了验证。     

Calibrating the GOCE accelerations with star sensor data and a global gravity field model

A reliable and accurate gradiometer calibration is essential for the scientific return of the gravity field and steady-state ocean circulation explorer (GOCE) mission. This paper describes a new method for external calibration of the GOCE gradiometer accelerations. A global gravity field model in combination with star sensor quaternions is used to compute reference differential accelerations, which may be used to estimate various combinations of gradiometer scale factors, internal gradiometer misalignments and misalignments between star sensor and gradiometer. In many aspects, the new method is complementary to the GOCE in-flight calibration. In contrast to the in-flight calibration, which requires a satellite-shaking phase, the new method uses data from the nominal measurement phases. The results of a simulation study show that gradiometer scale factors can be estimated on a weekly basis with accuracies better than 2 × 10⁻³ for the ultrasensitive and 10⁻² for the less sensitive axes, which is compatible with the requirements of the gravity gradient error. Based on a 58-day data set, scale factors are found that can reduce the errors of the in-flight-calibrated measurements. The elements of the complete inverse calibration matrix, representing both the internal gradiometer misalignments and scale factors, can be estimated with accuracies in general better than 10⁻³.     

Non-stationary covariance function modelling in 2D least-squares collocation

Standard least-squares collocation (LSC) assumes 2D stationarity and 3D isotropy, and relies on a covariance function to account for spatial dependence in the observed data. However, the assumption that the spatial dependence is constant throughout the region of interest may sometimes be violated. Assuming a stationary covariance structure can result in over-smoothing of, e.g., the gravity field in mountains and under-smoothing in great plains. We introduce the kernel convolution method from spatial statistics for non-stationary covariance structures, and demonstrate its advantage for dealing with non-stationarity in geodetic data. We then compared stationary and non- stationary covariance functions in 2D LSC to the empirical example of gravity anomaly interpolation near the Darling Fault, Western Australia, where the field is anisotropic and non-stationary. The results with non-stationary covariance functions are better than standard LSC in terms of formal errors and cross-validation against data not used in the interpolation, demonstrating that the use of non-stationary covariance functions can improve upon standard (stationary) LSC.     

村镇空间结构特征分析

以平原村镇香河县、山地村镇密云县和水乡村镇昆山市为研究区, 分析了村镇空间结构的特征。建立基于网格的村镇选址及空间范围模型, 采用GIS空间分析和建模技术实现; 此外, 空间范围模型根据泰森多边形模型的思想, 提出用土地效益的概念代替距离来确定村镇的空间范围。由于考虑因素更全面, 更具体, 这两个模型可以更好地为村镇的选址与空间范围的确定提供参考。此研究为村镇规划工作提供帮助。     

低轨卫星初始状态误差对反演地球重力场的影响

基于动力学法反演地球重力场的基本理论,研究了卫星初始状态向量误差对应用低轨卫星精密轨道数据反演地球重力场的影响。在仅考虑低轨卫星初始状态误差的情况下进行了模拟计算,结果表明:在利用低轨卫星精密轨道数据反演地球重力场时,卫星初始状态向量误差需要重新进行估计;在目前的轨道精度水平下,若不顾及误差方程二次项的影响,反演弧长不宜过长;卫星初始状态速度误差(约1.5mm/s)的影响要大于位置误差(约10 cm)的影响。     

基于能量守恒的星间距离变率与地球重力场频谱关系的建立与分析(英文)

The spectral relationship between range-rate measurements and the gravity potential for low-low satellite-to-satellite tracking mission was established based on the energy conservation theory. Then the performances of satellite separation, the orbital altitude, and the accuracy of range-rate measurements in recovering the earth’s gravity field were simulated and analyzed by this method. Finally, the cumulative geoid errors of the reference mode were obtained by using the configuration parameters of the GRAC...