GPS变形监测的似单差算法与粗差识别

根据高精度GPS变形监测的特点,建立了单历元解算变形量的似单差模型及其算法.该模型避免了周跳的探测与修复,可适用于动态、静态两种监测模式及同步观测卫星少于4颗的情况.在分析似单差模型的基础上,提出了识别载波相位观测值中小于半周的粗差的方法.利用试验数据对似单差模型的正确性及粗差识别方法的有效性进行了检验.     

GPS变形监测信息高精度快速解算方法研究

根据高精度GPS变形监测的特点，以监测网的首期观测成果为基础，利用监测时段的载波相位为基本观测量，建立了单历元解算监测点变形信息的似单差模型。该模型避免了周跳的探测与修复，可适用于动态和静态2种监测模式，并可适用于同步观测卫星较少(如2颗)的情况．最后利用试验数据对该模型的正确性进行了检验。     

VRS系统流动端单历元整周模糊度搜索

为了实现VRS系统虚拟参考站和流动端单历元模糊度快速搜索,采用宽巷相位和C码伪距观测值组成联合双差观测方程,用改进LAMBDA方法搜索宽巷载波双差模糊度,并提出双频相位观测值组合模型逐星固定L1和L2双差模糊度,研究结果表明:该方法具有很高成功率和效率,单历元定位精度优于3 cm,该研究实现流动端单历元实时高精度动态定位。     

基于补充卡尔曼滤波的载波相位平滑伪距算法

在高精度GPS接收机的基带信号处理中,利用载波相位对码伪距观测量进行平滑可以获得比伪码测量更高的精度。传统的载波相位平滑伪距算法适用于平滑历元数较少的情况,对短时多历元平滑的情况并不适用。针对这一问题,详细分析了传统载波相位平滑伪距算法在多历元平滑时所存在的不足,提出了在基带信号处理中采用补充卡尔曼滤波进行相位平滑伪距的算法,并给出了相应的数学解算过程和算法适用条件。仿真分析结果表明,由于补充卡尔曼滤波算法综合考虑了相关观测误差的影响,因此,当平滑历元数大于500时,补充卡尔曼滤波算法平滑精度要优于传统的平滑算法。     

GPS变形监测信息单历元解算的抗差估计方法研究

根据高精度GPS变形监测的特点,介绍了单历元解算监测点变形量的似单差数学模型及其算法．该算法不涉及周跳的探测与修复、双差整周未知数的解算等棘手问题,适用于同步观测卫星数不少于2颗的情况．为提高单历元解算变形信息的可靠性,在分析算法的基础上,构造了实现对卫星进行自动选择的抗差估计模型．3个不同测区的试验数据计算结果表明,本文建立的似单差模型是正确的,采用抗差估计方法来选择卫星也是可行的．     

多约束条件的全球定位系统单频单历元短基线定向技术与实现

通过研究全球定位系统(GPS)伪距测量精度对GPS载波相位差分技术在短基线定向问题中的影响,提出利用基线长度、基线俯仰、卫星之间几何关系的多约束最小二乘整周模糊度实时搜索算法,给出单频单历元进行短基线定向的具体过程和需要注意的关键问题.算法采用单历元解算,规避载波相位周跳问题,极大地减小初始化时间.静态和动态实验结果均表明:该方法快速有效,解算成功率高,具有较高的定向精度.     

适用于航天器的GPS姿态测量算法和软件设计

为发展小卫星 ,需要研制成本低、小而轻又能满足精度的姿态测量系统。论述了利用全球定位系统 ( GPS)载波相位观测值进行姿态测量的原理 ,介绍了航天器姿态测量软件 THADS的算法和软件设计。在软件设计时 ,采用了周跳和粗差判定的改进方法 ,编制了相应的模块 ,结合地面实验数据进行仿真计算 ,在 1m左右的基线上姿态均方差小于0 .4°。结果表明利用 GPS载波相位进行航天器姿态测量具有良好的应用前景     

基于双频载波相位组合的变形信息逐步精化方法

针对GPS动态变形监测,利用监测点位置精确已知的条件,提出了一种新的单历元变形信息解算算法,避开了整周模糊度的求解和周跳的探测与修复,极大简化了数据处理过程.针对较大的瞬时变形量,首先采用长波长的双频载波相位组合观测量进行求解,然后利用宽巷和L1载波相位观测量进行逐步精化处理,从而可以精确求解高达0.8 m的瞬时变形量.静态和动态实验结果表明,该方法可以达到±5 mm的精度,能够有效应用于快速变形监测.     

基于多接收机的本地监测系统监测算法研究

本地监测系统可以增强卫星导航系统的性能以满足航空用户的需求。针对目前单接收机本地监测系统在进近着陆应用中各导航性能存在的不足,提出了一种基于多接收机的本地监测系统完好性监测算法。该算法考虑了地面接收机故障对用户安全造成的影响,从而提高了系统的完好性。另外,该算法通过利用既有的增强系统完好性信息,改善了系统对本地差分修正误差的监测能力;并且通过使用卫星信号双频观测量,提高了用户的观测精度。上述优化可有效降低保护门限值,最终达到提高系统可用性的目的。应用该算法增强北斗卫星导航(区域)系统,可在我国及周边地区满足I类精密进近的性能指标要求,并且平均可用性达到95.57%。     

基于组合载波相位的飞行器姿态确定

为解决全球导航卫星系统(GNSS)姿态测量中整周模糊度的快速求解问题,提出一种基于组合载波相位的短基线整周模糊度解算方法,利用单个历元的观测数据解算整周模糊度.根据多颗卫星的单频载波相位整周模糊度解算结果,应用最小二乘原理对基线向量进行精确求解,进而由基线向量确定出飞行器的姿态角.仿真结果表明,该模糊度解算方法在单个历元内至少能够解算出8颗卫星的载波相位整周模糊度,解决了GNSS动态测姿领域的一个关键性问题.测姿结果显示,偏航角和俯仰角的测量误差均小于0.2°.该研究成果可以为GNSS姿态测量系统在航空、航天等对实时性要求较高的领域中的应用创造条件.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that