GPS三频数据在周跳和粗差探测与修复中的应用

通过多频载波相位组合观测值的长波长特性，结合传统的伪距/载波探测原理，利用模拟的GPS多频数据进行了各种情况下周跳与粗差的探测及修复，同时对一条GPS基线进行了原始观测数据预处理的实例分析.结果表明，通过多频数据组合能够完全实时修复大采样率条件下各种情况的周跳，可以实时探测出0.2周以上的粗差.     

三频数据组合在北斗卫星周跳探测与修复中的应用

随着多频卫星导航信号的播发,利用多频观测数据组合对周跳进行快速准确的探测与修复将会得到广泛的应用。该文介绍了北斗三频数据组合周跳探测与修复的原理,结合多频载波相位组合观测值长波长及低噪声的性质,选取(4,-2,-3)、(-1,-5,6)和(-4,1,4)线性无关的相位组合,探讨了该组合下伪距/相位组合法在不同周跳情况下的周跳探测性能。结果表明三频伪距/相位组合法对单频点周跳和多频点同时周跳都具有快速准确地探测效果,可以很好的对北斗实测数据进行实时周跳探测与修复工作。     

Geometry-Free和Melbourne-Wübbena联合探测GPS周跳的实际效果

为完整地探测和修复GPS观测数据所有周跳,该文提出了一种综合利用宽巷相位减窄巷伪距(MW组合)和电离层残差法(GF组合)探测和修复周跳的方法。并通过实验表明,所提方法克服了单独使用两种方法时不能探测到一定组合的周跳的缺陷,能够准确地探测和修复一周以上周跳,并一定程度的减少了计算量。     

一种GPS单频接收机钟跳实时探测与修复方法

GPS（Global positioning system）在矿区测图与变形监测方面发挥了重要作用,但GPS接收机钟的不稳定直接影响了定位解算结果的精度,有必要准确有效地对GPS观测值中的接收机钟跳进行探测与修复。针对现有GPS接收机钟跳探测与修复方法的不足之处,提出了一种观测值域内GPS单频接收机钟跳与周跳同时存在时钟跳的实时探测与修复方法。首先通过星间和历元间组成双差观测量,对GPS接收机原始观测值中的钟跳与大周跳进行有效分离;然后利用伪距与载波观测值相邻历元间的二次差线性组合求解钟跳量级;最后对伪距观测值钟跳引起的跳变进行修复。分别采用IGS（International GNSS service）跟踪站采集的数据以及淮南某矿区的GPS观测数据进行周跳探测与修复试验,结果表明：针对不同类型的GPS接收机,所提出的方法可有效探测和修复GPS单频接收机钟跳,有助于提高GPS单频接收机的数据质量,对于提高矿区测图与变形监测精度具有一定的作用。     

GPS周跳探测两种方法的研究

在GPS周跳探测中,如何快速有效的探测出小周跳和大周跳是非常关键的技术问题,为此文中针对GPS定位中周跳探测这一难题入手。基于双频接收机的观测值,对电离层残差法、相位减伪距法进行周跳探测的研究,并通过实例分析验证这两种探测方法的有效性。     

基于MATLAB的GPS周跳探测与修复

在GPS观测过程中,信号会受到遮挡等原因发生跳变现象,引起很大误差甚至是粗差,为了解决这一问题,文中利用MATLAB软件,根据电离层残差法和Melbourne-Wübbena组合法的优缺点,结合这两种方法进行GPS载波相位观测值的周跳探测,然后根据周跳探测结果进行修复,结果表明:利用组合方法编制的MATLAB周跳探测与修复的程序能很好的探测和修复GPS周跳.     

北斗非差数据MW/TECR组合周跳探测与修复

矿区边坡变形监测在矿山可持续安全开采中发挥着重要的作用。在利用GNSS(Global navigation satellite system)技术对矿区边坡进行高精度监测时,必须准确地对GNSS相位观测数据进行周跳探测与修复。提出了利用MW/TECR(Melbourne Wubbena/Total electron contents rate)组合对北斗非差相位数据进行周跳实时探测与修复的方法。首先选取MW/TECR组合作为周跳检测量,对北斗导航卫星的B1和B2载波上出现的周跳进行探测,然后以最小1范数作为周跳修复准则,以一定的搜索半径对周跳估值的最小二乘解进行搜索匹配修复周跳,最后利用某露天矿区实测北斗相位观测数据进行周跳探测与修复试验。结果表明,MW/TECR组合可以有效地探测与修复原始相位观测数据中所添加的各种周跳,显著地改善北斗相位观测数据质量,对于提高矿区边坡监测的精度具有一定的作用。     

改进的电离层残差法在北斗周跳探测与修复中的应用

小周跳的探测与修复一直是高精度北斗导航定位研究中的热点领域。该文针对常规的电离层残差法解算北斗双频周跳时出现的解的多值问题,通过结合伪距差分约束条件来确定周跳,并结合北斗数据实例,证明该方法可以有效探测北斗小周跳并解决周跳解多值性问题。     

三频周跳探测与修复方法研究

文中对三频组合特性进行了系统性的研究,通过搜索得出(0,1,-1)、(1,-8,7)、(4,-8,3)等三频组合都有相对较好的特性。在研究了传统的伪距减相位组合周跳探测算法基础上,对于组合探测值的选择原则进行了深入探究,放宽了整数空间到整数空间的这一严格原则,并且给出了证明,从而拓展了该方法中周跳探测组合观测值的数量。     

基于Hatch滤波的GPS伪距相位平滑及其在单点定位中的应用

该文首先给出了利用高精度载波相位观测值对GPS伪距观测值进行相位平滑的数学模型,分析了电离层折射误差对伪距相位平滑的影响。采用Hatch滤波实现相位平滑伪距的逐历元递推计算,并将其应用于单点定位。借助自编伪距单点定位程序,对基于Hatch滤波方法的GPS相位平滑伪距及其单点定位的精度进行了研究和验证。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.