|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | GPS接收机仪器偏差的短期时变特征提取与建模显示文摘卫星和接收机仪器偏差(Differential Code Biases,DCB)是利用GPS(Global Positioning System)研究电离层的两类主要误差源.由于所处的空间环境恒定,且可被全球跟踪站连续观测,GPS卫星的DCB具备长期稳定性和较高的估计精度.但针对各类型接收机而言,受测站环境、硬件设施等影响,其DCB可能会呈现明显的短期变化.精确地模型化接收机DCB的短期变化特征,将有助于提高GPS电离层产品的可靠性,以及基于这些产品反演空间和地球科学现象的准确性.采用零/短基线GPS数据,本文改进了提取和分析接收机DCB变化的现有方案.随后,本文推导了一种能直接估计接收机DCB的函数模型.当检验出接收机DCB的短期变化服从随机游走时,通过对比接收机DCB的直接估值与间接提取值之间的符合程度,可"试探出"过程噪声标准差的最优经验值.实验分析选用4台双频接收机(共形成1条零基线和2条短基线,间距最大为15m)多天的观测数据,主要结论包括:1)改进的接收机DCB提取方案能较好地克服低频伪距噪声和多路径效应的影响;2)针对零基线,其接收机DCB在各天内的变化量级小于1TECu,变化趋势则可采用过程噪声标准差为1.0~1.5mm的随机游走加以描述;3)对应于某短基线的接收机DCB在某天内的变化可达12TECu,当采用随机游走描述其趋势时,过程噪声标准差的经验值超过2mm. | 张宝成 袁运斌 欧吉坤 | 2016 | 地球物理学报2016，59，1： | 14 |
| 2 | Characterization of multi-GNSS between-receiver differential code biases using zero and short baselines显示文摘Care should be taken to minimize adverse impact of receiver differential code biases(DCBs) on global navigation satellite system(GNSS)-derived ionospheric parameters. It is therefore of importance to ascertain the intrinsic characteristics of receiver DCBs,preferably in the context of new-generation GNSS. In this contribution, we present a method that enables time-wise retrieval of between-receiver DCBs(BR-DCBs) from dualfrequency, code-only measurements collected by a pair of co-located receivers. This method is applicable to the US GPS as well as to a new set of GNSS constellations including the Chinese Bei Dou, the European Galileo and the Japanese QZSS. With the use of this method, we determine the multi-GNSS BR-DCB time-wise estimates covering a time period of up to 2 years(January 2013–March 2015) with a 30-s time resolution for five receiverpairs(four zero and one short baselines). For the BR-DCB time-wise estimates pertaining to an arbitrary receiver-pair and constellation, we demonstrate their promising intraday stability by means of statistical hypothesis testing. We also find that the Bei Dou BR-DCB daily weighted average(DWA) estimates show a dependence on satellite type, in particular for receiver-pairs of mixed types. Finally, we demonstrate that long-term variability in BR-DCB DWA estimates can be closely associated with hardware temperature variations inside the receivers. | Baocheng Zhang Peter J.G.Teunissen | 2015 | Science Bulletin2015，60，21： | 10 |
| 3 | 中国电离层TEC同化现报系统显示文摘数据同化是在基于物理机制的背景模型上,融合时空不规则分布的观测数据的一种现报方法.同化能够有效弥补数据的时空局限和模型的精度偏差,使二者相互匹配从而获得更加合理可信的模拟效果.本研究利用电离层数据同化方法,针对中国及周边区域(15°N—55°N,70°E—140°E)构建了电离层总电子含量(TEC)同化现报系统.系统使用国际参考电离层(IRI)作为背景场,利用中国科学院空间环境监测网和国际GNSS服务组织(IGS)的部分地基GNSS台站数据作为观测值,并采用三维变分与Gauss-Markov卡尔曼滤波相结合的算法进行背景场和观测值的数据同化,生成覆盖中国及周边区域的电离层TEC和GPS单频接收机延迟误差的格点化准实时现报地图,并在中国科学院空间环境预报中心(http:∥sepc.ac.cn/TEC_chn.php)网上发布,每15min进行更新.该系统是我国基于同化算法的电离层现报系统之一,已用于中国及周边区域的电离层环境实时监测,可为卫星导航、雷达成像、短波通信等科学研究和工程应用提供相对及时、准确、有效的电离层TEC和误差修正信息. | 阿尔察 刘四清 黄文耿 李建勇 师立勤 龚建村 陈艳红 沈华 蔡燕霞 鲁国瑞 | 2018 | 地球物理学报2018，61，6： | 9 |
| 4 | BDS卫星差分码偏差稳定性分析及其短期预报显示文摘利用MGEX(multi-GNSS experiment)发布的BDS卫星差分码偏差(differential code bias,DCB)产品,比较分析不同太阳活动水平下BDS卫星DCB产品的稳定性变化特性,并采用差分自回归移动平均(auto-regressive integrated moving average,ARIMA)时间序列预测模型,实现不同太阳活动水平下BDS卫星DCB的短期预报。结果表明,在太阳活动高年,BDS卫星DCB日解值稳定度、月稳定性均明显低于太阳活动低年,且不同卫星星座类型的BDS卫星DCB稳定性也存在差异;ARIMA时间序列预报结果与MGEX发布值符合程度较好,优于多项式拟合法预测结果。 | 梅登奎 闻德保 | 2020 | 大地测量与地球动力学2020，40，7： | 7 |
| 5 | A novel satellite-equipped receiver for autonomous monitoring of GNSS navigation signal quality显示文摘Global navigation satellite system(GNSS) comes with potential unavoidable application risks such as the sudden distortion or failure of navigation signals because its satellites are generally operated until failure. In order to solve the problems associated with these risks, receiver autonomous integrity monitoring(RAIM) and ground-based signal quality monitoring stations are widely used. Although these technologies can protect the user from the risks, they are expensive and have limited region coverage. Autonomous monitoring of satellite signal quality is an effective method to eliminate these shortcomings of the RAIM and ground-based signal quality monitoring stations; thus, a new navigation signal quality monitoring receiver which can be equipped on the satellite platform of GNSS is proposed in this paper. Because this satellite-equipped receiver is tightly coupled with navigation payload, the system architecture and its preliminary design procedure are first introduced. In theory, code-tracking loop is able to provide accurate time delay estimation of received signals. However, because of the nonlinear characteristics of the navigation payload, the traditional code-tracking loop introduces errors. To eliminate these errors, the dummy massive parallel correlators(DMPC) technique is proposed. This technique can reconstruct the cross correlation function of a navigation signal with a high code phase resolution. Combining the DMPC and direct radio frequency(RF) sampling technology, the satellite-equipped receiver can calibrate the differential code bias(DCB) accurately. In the meantime, the abnormities and failures of navigation signal can also be monitored. Finally, the accuracy of DCB calibration and the performance of fault monitoring have been verified by practical test data and numerical simulation data, respectively. The results show that the accuracy of DCB calibration is less than 0.1 ns and the novel satellite-equipped receiver can monitor the signal quality effectively. | YANG Jian YANG YiKang LI Ji Sheng LI HengNian YANG TianShe | 2016 | Science China(Technological Sciences)2016，59，7： | 6 |
| 6 | 基于单站多系统的GNSS硬件延迟估算方法及其应用显示文摘随着全球导航卫星系统(Global Navigation Satellite Systems,GNSS)的不断发展,中国地区单个GNSS接收站在一个时刻可以接收到超过30颗GNSS卫星的信号,这为单站GNSS硬件延迟估算方法的研究提供了有利条件.本文首先通过GNSS硬件实验,分析了不同温度条件下GNSS系统硬件延迟的变化特征,研究结果显示:当温度快速变化时,硬件延迟变化比较剧烈,变化幅度可达12.53TECU(1TECU=10 16el·m-2);在恒温条件或室温条件下,硬件延迟变化比较缓慢,变化幅度在1.00TECU左右.在GNSS系统硬件延迟实验的基础上,充分利用单站多星观测的特点,提出了一种基于单站多系统的GNSS硬件延迟的估算方法——单站三角分解与差分消元法,并将该方法应用于河北保定站2015—2017年GNSS系统硬件延迟的求解中.通过对估算的GNSS系统硬件延迟进行分析显示:单站三角分解与差分消元法具有计算速度快、独立性好的特点;在北斗系统上硬件延迟的求解效果优于GPS、GLONASS系统,硬件延迟求解的结果整体上比利用欧洲定轨中心全球电离层地图校正的结果大2.50~3.00TECU左右;同时,该方法在消除GNSS系统硬件延迟后,获得的垂直总电子含量(Total Electron Content,TEC)能较好地反映电离层TEC的周日变化、日出增强、半年变化、年变化和春秋分不对称性等特征. | 熊波 李肖霖 万卫星 佘承莉 胡连欢 丁锋 赵必强 | 2019 | 地球物理学报2019，62，4： | 5 |
| 7 | Acquisition algorithm assisted by AGC control voltage for DSSS signals显示文摘An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm. | SHEN YuYao WANG YongQing LIU MinLi WU SiLiang | 2015 | Science China(Technological Sciences)2015，58，12： | 4 |
| 8 | 基于等离子体GCPM模型对电离层薄壳模型高度的仿真研究显示文摘在基于GPS数据提取电离层总电子含量(TEC)的过程中,电离层薄壳高度的选择对解算电离层垂直TEC的精度有很大的影响.但由于不可能获得一个真实的从电离层D层到GPS卫星高度的电子密度剖面,关于电离层薄壳高度的选择一直是基于GPS数据解算电离层TEC方法中关注的一个问题.本文利用等离子体GCPM模型,对太阳活动高年(2002)和太阳活动低年(2008)情况下电离层有效薄壳高度的选择进行了仿真计算.结果表明,最佳的薄壳高度在2002年为560km,而在2008年为695km.通过对全球八个具有代表性地点的仿真计算,揭示了有效薄壳高度更复杂的变化特点.在白天,最佳薄壳的高度变化不大(500km至750km);但在夜晚,最佳薄壳高度变化范围很大,甚至可以超过2000km.此外,本文还对不同卫星仰角的情况下斜向TEC转换为垂直TEC的误差进行了分析,结果表明:随着卫星仰角的增加,薄壳模型带来的转换误差基本上是单调减少的.因而,在实际应用中,尽可能地采用大仰角的卫星数据有助于提高解算的电离层垂直TEC的精度.最后,对全球不同地点的电离层TEC的仿真研究表明,在电子密度水平梯度较大的地区,应用电离层薄壳模型时会导致电子密度较高处的TEC被高估,而电子密度较低处的TEC被低估,在分析基于GPS数据提取的电离层TEC空间变化时要认识到这一点. | 郭佳鹏 张东和 郝永强 肖佐 | 2014 | 地球物理学报2014，57，11： | 3 |
| 9 | Research on assessment method of intrasystem and intersystem of the global navigation satellite system显示文摘The global navigation satellite system(GNSS) has become an important space infrastructure. Following GPS and GLONASS, Europe and China have been building their own global navigation satellite system, respectively, GALILEO and Compass. In order to consolidate the leadership of GPS in the globe, United States is gradually upgrading the traditional GPS. Simultaneously, Russia is also intensively restoring full performance of GLONASS. With the advancement of international satellite navigation system, satellite navigation frequency resources are already in short supply, and the design and use of the navigation signals are more sophisticated and complex due to commercial, disaster relief and other reasons. Since there may be many navigation signals in the same basic bandwidth, the coexistence of multiple systems and the combined application make intersystem mutual interference become the focus research. Under this background, the satellite navigation system mutual interference evaluation system needs to be established urgently to meet and support the compatibility and interoperability of the GNSS system. In the paper, through the performance analysis of the GNSS signal acquisition, carrier tracking, data demodulation and code tracking, the equivalent carrier to noise ratio model based on spectrum isolation coefficient is established, and the theoretical system of the GNSS signal mutual interference is proposed according to the mechanism, and the mutual interference of GPS, GALILEO and Compass system is analyzed and assessed. | ZHANG JianJun XUE Ming XIE Jun | 2015 | Science China(Technological Sciences)2015，58，10： | 3 |
| 10 | A regional ionospheric TEC mapping technique over China and adjacent areas: GNSS data processing and DINEOF analysis显示文摘A technique is developed to derive two-dimensional maps of total electron content(TEC) over China and adjacent areas using Global Navigation Satellite System(GNSS) data from the Crustal Movement Observation Network of China(CMONOC) and the International Global Navigation Satellite System Service(IGS). A revised self-calibration of pseudo-range errors(SCORE) algorithm is used to derive the TEC and to determine the Differential Code Biases(DCBs) simultaneously. The accuracy and validity of this technique is verified in two ways. Firstly, the estimated TEC is compared with the results derived using DCBs from Center for Orbit Determination of Europe(CODE) under different solar activity conditions and seasons; secondly, sample TEC along the receiver-to-satellite ray paths are simulated by Ne Quick model and are reprocessed by this TEC derivation technique to make the accuracy test. Two-dimensional maps of vertical TEC of ionospheric pierce points(IPPs) are obtained accordingly with a time resolution of 30 s. The data interpolating empirical orthogonal functions(DINEOF) technique is then used to make the extrapolation for the unknown or missing data points. The optimal EOF modes for data reconstruction are specified via cross-validation method. The regional TEC distribution over China and adjacent areas is scaled into grid size of 1? × 1? for each 5 min, which can well reflect the characteristic of large-scale regional variations and temporal evolution as well as the small-scale local features of ionosphere. | A Ercha HUANG WenGeng LIU SiQing SHI LiQin GONG JianCun CHEN YanHong SHEN Hua | 2015 | Science China(Information Sciences)2015，58，10： | 3 |
| 11 | 电离层周日变化对解算GPS硬件延迟稳定性的影响显示文摘针对电离层周日变化特征分析了其可能对SCORE方法估算的硬件延迟稳定性的影响.利用BJFS以及XIAM台站的GPS观测数据,解算了位于太阳活动高年(2001年)和太阳活动低年(2009年)的卫星硬件延迟并分析了估算的硬件延迟的稳定性.研究发现,电离层周日变化对估算的硬件延迟稳定性具有一定影响,但是利用不同台站所得到的卫星硬件延迟稳定性在昼夜不同时间上的解算结果存在一定差异.电离层周日变化对利用BJFS台站数据解算的硬件延迟稳定性日夜差异较为明显,在太阳活动高年利用ⅪAM台站数据解算的硬件延迟日夜稳定性差异不很明显,由于XIAM台站处于电离层赤道异常峰附近,夜间电离层变化很大,因此对比中纬度地区,电离层周日变化对赤道异常峰附近地区硬件延迟稳定性解算结果的影响相对较小,但在太阳活动低年,其影响仍较为显著. | 李灵樨 张东和 郝永强 萧佐 | 2015 | 空间科学学报2015，35，2： | 2 |
| 12 | Some Investigations on the Ionosphere during 2012–2014 in China显示文摘In this national biannual report, we will outline some recent progresses in ionospheric studies conducted by Chinese scientists since 2012. The mentioned aspects include: the solar activity control of the ionosphere; couplings between the ionosphere, lower atmosphere and plasmasphere;ionospheric climatology and disturbances; ionospheric irregularities and scintillation; models, data assimilation and simulations; unusual phenomena of the ionosphere; possible seismic signatures presented in ionospheric observations, and some methodology progresses. These progresses will enhance our ability to observe the ionosphere, provide more reasonable understanding about the states of the ionosphere and underlying fundamental processes, and stimulate ionospheric modeling, forecasting and related applications. | LIU Libo CHEN Yiding LE Huijun LIU Jing WAN Weixing | 2014 | 空间科学学报2014，34，5： | 0 |
| 13 | 北京地区电离层COSMIC掩星与垂测仪探测临界频率数据对比显示文摘使用COSMIC掩星和垂测仪,探测2011—2012年北京地区电离层临界频率数据,比较不同探测手段获取的电离层特征参量随地方时和地磁季节相关性的变化。研究表明:2组数据具有较好的相关性;标准偏差随地方时变化,日出时6:00 LT开始增大,日落时16:00LT到次高值,19:00LT达最大值后开始下降;标准偏差随地磁季节变化,夏季最小,冬季最大。分析认为,电子密度在垂直和水平方向上的梯度变化,造成掩星反演误差增大,可能导致了数据相关性在不同地磁季节和地方时刻的相应变化。 | 马新欣 刘晓灿 焦立果 | 2017 | 地震地磁观测与研究2017，38，3： | 0 |
| 14 | 2012年北大北京本校站电离层TEC和闪烁指数集显示文摘电离层总电子含量(TEC)和闪烁指数是电离层形态学研究的重要参数。基于二者描述电离层状态,对电离层研究有十分重要的意义。2012年北大北京本校站(116.30°E,39.99°N)电离层TEC和闪烁指数是根据GPS伪距及载波相位观测数据、信号功率、信噪比获得的。该数据集包含电离层垂直TEC、幅度闪烁指数和相位闪烁指数。通过这一数据可以得到电离层TEC同太阳活动、磁暴、电离层暴之间的关系,以及电离层不规则体的逐日变化和暴时特征。本数据集能够为我国众多空间环境相关的研究与工程项目提供数据保障。 | 李灵樨 张东和 邹自明 钟佳 胡晓彦 纪珍 郝永强 | 2016 | 中国科学数据(中英文网络版)2016，1，3： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员