大气引力负荷格林函数

主要研究大气引力变化对地表位移的影响，在经典的负荷理论基础上，从运动方程着手，定义了大气引力勒夫数，并推导了高阶引力勒夫数的渐近表达式、大气引力造成的地球变形的地表位移、重力、地倾斜、应变等格林函数；编写程序计算了引力勒夫数和地球形变格林函数的理论值。     

大气负荷格林函数的压强效应

定义了大气压强负荷勒夫数，给出了大气压强引起的地球变形格林函数的表达式，利用程序计算了大气压强负荷勒夫数和格林函数。     

机极冰盖部分消融对海平面的影响

本文假设地球具球对称，完全弹性和各向同性，推导了冰融相对海平面变化方程，采用汪汉胜等根据ＰＲＥＭ模型计算的地表弹性负荷勒夫数，估算了在今后５０年内，当南极冰盖消融１０米时所产生的全球海平面变化。     

南极冰盖部分消融对海平面的影响

本文假设地球具球对称、完全弹性和各向同性，推导了冰融相对海平面变化方程，采用汪汉胜等（１９９６）根据ＰＲＥＭ（１９８１）模型计算的地表弹性负荷勒夫数，估算了在今后５０年内，当南极冰盖消融１０米时所产生的全球海平面变化     

应用人卫激光测距技术测定潮汐形变勒夫数

本文讨论了利用人卫激光测距（ＳＬＲ）资料确定分潮波形式的地球固体潮汐形变勒夫数的可能性,并用１１年的Ｌａｇｅｏｓ－１的人卫激光测跨资料直接解算了四个周日波Ｑ、,Ｏ１,Ｐ１,Ｋ１和四个半日波Ｓ２,Ｋ２,Ｎ２,Ｍ２的弹性和粘弹性地球状态下的地球潮汐形变勒夫数ｈ２ｓ,ｌ２ｓ,结果与ＶＬＢＩ结果相符,与ＩＥＲＳ及Ｗａｈｒ的模型值的潮汐响应趋势相符,这证明了利用ＳＬＲ技术确定潮汐形变勒失数是可行的,从而为传统技术和空间技术提供了一种新的有意义的方法和选择。     

利用独立成分分析法研究新疆地区陆地水储量及其地壳垂向变化

中国新疆地区水文气候变化复杂,其水储量变化及其负荷形变特征的精确提取极为重要。采用卫星重力数据GRACE(gravity recovery and climate experiment）反演新疆地区2010—2014年陆地水储量变化,利用独立成分分析法（independent component analysis,ICA）分解时空模式,提取时空特征信号。在此基础上,反演陆地水负荷迁移引起的地壳垂向变化,引入重力位系数与负荷勒夫数一阶项改正,回加非潮汐大气与海洋信号,结合尺度因子法校正GRACE反演结果,引入全球降水气候计划月降水资料分析形变影响,将其与测区12座连续运行参考站形变位移进行定量比较,重点分析各测站陆地水负荷信号与全球导航卫星系统（global navigation satellite system,GNSS）垂直位移的相关关系。结果表明,经ICA方法分解的新疆地区陆地水储量呈现多时间尺度特征,表现为明显的周年与长期变化;周年信号在西部帕米尔高原附近尤为显著;长期变化以逐年减少为主,在乌鲁木齐西部、天山一带信号较强;总体上,陆地水负荷垂直形变的时间序列波动幅度相对较小,幅值...     

大气负荷和内陆水负荷对GPS测高影响的研究

讨论了大气负荷、内陆水负荷等环境负荷对GPS高程影响的计算公式和方法，并进行了实例计算，得出了有益的结论。     

利用海潮模型研究D-InSAR中的海潮负荷效应

海潮负荷位移在沿海区域的相对形变可达数厘米,所以在沿海区域使用差分干涉合成孔径雷达(differential in-terferometric synthetic aperture radar,D-InSAR)测量微小形变时,须考虑海潮负荷影响.本文利用美国南加州8个验潮站的潮高数据,对两个全球海潮模型FES2004、...     

海潮对高精度GPS网的影响初探

本文叙述了海洋负荷潮改正的基本原理，结合算例分析了海潮对GPS网的影响，结果显示：对于近海地区较短时段的GPS观测，考虑海潮负荷改正可以明显地提高解算精度，特别对改善高程方向的精度贡献明显。影响可达数厘米，这种影响的量级对水平方向不明显；对于远离海洋地区，海潮负荷改正的影响已不明显，可以不与考虑。     

2000—2015年中国大陆海洋岸线变化多视角分析

针对中国大陆海洋岸线在宏观尺度、长时间序列下分析角度较少的问题,该文利用遥感与GIS技术,以2000、2015年2个时期为特征年,从海洋岸线长度与结构、分形维数、岸线变化速率与稳定性、开发利用负荷等角度,综合分析2000—2015年中国大陆海洋岸线时空变化特征。结论如下:①近15年来,海洋岸线总长度增加1 716km,岸线结构变化显著,人工岸线剧增,自然岸线锐减;②海洋岸线分形维数呈增长趋势,具有"北方<全国<南方"的宏观格局特征;③海洋岸线年均变化速率为33.03(m·a~(-1)),岸线的变化速率、稳定性具有显著的空间差异性,北方向海扩张趋势较集中、规模较大;④中国大陆海洋岸线约30%为开发岸线,且海岸开发以重度为主,分布不均,北方岸线开发利用负荷度较高。     

A Closed-Form Expression of the Electromagnetic Tensor Green's Functions for a Homogeneous TI-Anisotropic Medium

In this letter, the electromagnetic fields from electric and magnetic current source distributions located in an unbounded homogeneous transverse isotropic (TI)-anisotropic medium are determined. The expressions provide the closed-form tensor Green's functions needed in any integral equation formulation of the forward as well as the inverse scattering problems associated with scatterers embedded in a homogeneous TI-anisotropic medium     

球域调和函数外部边值问题的格林函数解

本文找到了球域三类边值问题的格林函数，所得格林函数解与球函数解相同。     

On the Distribution of the Estimated Coherence

The recent paper by Abdelfattah and Nicolas proposed a novel coherence magnitude estimator and studied its properties. Here, we derive simpler and more explicit expressions for four of the properties that were studied: 1) the probability density function; 2) moments; 3) Mellin transform; and 4) second-kind moments. We establish numerical efficiency of these expressions and provide simple Maple programs for inversion. We expect that the results presented here could enhance applicability of the new estimator.     

Explicit expression and regularization of the harmonic reproducing kernels for the earth's ellipsoid

The reproducing kernel functions and the integral formulae involving the solutions of the fixed gravimetric boundary value problems for the earth's ellipsoid are investigated in a suitable polar coordinate system defined on the boundary ellipsoid. The infinite series expressions of the reproducing kernel functions are represented explicitly up to the square of the first excentricity of the boundary surface. The obtained results show that the reproducing kernel functions for the earth's ellipsoid are, in contrast to the case of the spherical boundary, inhomogeneous and anisotropic. Moreover, the anisotropy is stronger near the pole. Subsequently the kernel functions are regularized in order to overcome the weak singularity of the integrals.     

Electromagnetic Scattering by Anisotropic Inhomogeneous Impedance Cylinder of Arbitrary Shape Using Physical Optics

In this letter, electromagnetic scattering from inhomogeneous anisotropic impedance cylinder of arbitrary shape is investigated by physical optics (PO) method. After the expressions of induced electric and magnetic currents on the illuminated region of surface are expressed by using PO approximation, scattered field is calculated using Huygens-type Green's formula. Obtained scattering width results are compared with those obtained by numerical methods such as NystrÖm and Method of Moments (MoM), and good agreements are observed particularly in monostatic case. Due to the fact that PO method does not need matrix inversion which requires high CPU time, it also significantly reduces computer calculation time in comparison to NystrÖm and MoM.      

关于“新的点位误差度量”的讨论

多维点位误差度量应该反映点的位置的不确定度,它可以是方差或方差的某种函数.实践中,有多种点位误差的表示形式,不同的表示形式有不同的几何意义或概率意义.文献[1]提出采用坐标分量方差的均值作为点位误差的度量.为了将其与现有点位误差度量进行比较,本文列出4种点住误差度量表达式,并讨论了它们的几何意义.强调指出,点位误差度量的具体数值应大于等于最大可能的误差,以保证用户使用数据的安全性.     

Construction of Green's function for the Stokes boundary-value problem with ellipsoidal corrections in the boundary condition

Green's function for the boundary-value problem of Stokes's type with ellipsoidal corrections in the boundary condition for anomalous gravity is constructed in a closed form. The `spherical-ellipsoidal' Stokes function describing the effect of two ellipsoidal correcting terms occurring in the boundary condition for anomalous gravity is expressed in O(e <sup>2</sup> <sub>0</sub>)-approximation as a finite sum of elementary functions analytically representing the behaviour of the integration kernel at the singular point ψ=0. We show that the `spherical-ellipsoidal' Stokes function has only a logarithmic singularity in the vicinity of its singular point. The constructed Green function enables us to avoid applying an iterative approach to solve Stokes's boundary-value problem with ellipsoidal correction terms involved in the boundary condition for anomalous gravity. A new Green-function approach is more convenient from the numerical point of view since the solution of the boundary-value problem is determined in one step by computing a Stokes-type integral. The question of the convergence of an iterative scheme recommended so far to solve this boundary-value problem is thus irrelevant. Received: 5 June 1997 / Accepted: 20 February 1998     

中国地壳运动观测网络基准站应变场变化的海潮负荷信号改正问题

利用最新的卫星测高全球Csr3.0模型，中国近海海潮数据和标准地球模型负荷格林函数，采用直接褶积积分方法研究中国地壳运动观测网络基准站应变固体潮观测的海潮负荷影响。计算25个台站8个主要潮波的负荷振幅和相位，讨论几个主要台站的负荷应变花和负荷应变随时间的变化特征。