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Orbit determination and time synchronization for a GEO/IGSO satellite navigation constellation with regional tracking network

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Science china(Physics,Mechanics & Astronomy) 2011年第6期54卷 1089-1097页

作者： zhou shanshi {2. xiaogong WU bin LIU Li QU WeiJing GUO Rui HE Feng CAO YueLing Wu XiaoLi Z{2. LingFeng SHI Xin TAN HongLi shanghai astronomical {2. Chinese Academy of SciencesShanghai 200030China Graduate University of chinese academy of sciences Beijing 100049China Beijing Global Information Application and Development Center Beijing 100094China

Aiming at regional services,the space segment of COMPASS (Phase I) satellite navigation system is a constellation of Geostationary Earth Orbit (GEO),Inclined Geostationary Earth Orbit (IGSO) and Medium Earth Orbit (MEO) *** orbit determination (POD) for the satellites is limited by the geographic distribution of regional tracking *** time synchronization (TS) system is developed to supplement the regional tracking network,and satellite clock errors and orbit data may be obtained by simultaneously processing both tracking data and TS ***,inconsistency between tracking system and TS system caused by remaining instrumental errors not calibrated may decrease navigation *** the other hand,POD for the mixed constellation of GEO/IGSO/MEO with the regional tracking network leads to parameter estimations that are highly *** example of correlation is found between GEO's orbital elements and its clock *** estimate orbital elements and clock errors for a 3GEO+2.GSO constellation in this study using a multi-satellite precise orbit determination (MPOD) strategy,with which clock error elimination algorithm is applied to separate orbital and clock estimates to improve numerical *** Laser Ranging (SLR) data are used to evaluate User Ranging Error (URE),which is the orbital error projected on a receiver's line-of-sight ***-way radio-wave time transfer measurements are used to evaluate clock *** with data from the regional tracking network,we conclude that the fitting of code data is better than 1 m in terms of Root-Mean-Square (RMS),and fitting of carrier phase is better than 1 *** orbital evaluation,difference between computed receiver-satellite ranging based on estimated orbits and SLR measurements is better than 1 m (RMS).For clock estimates evaluation,2.hour linear-fitting shows that the satellite clock rates are about 1.E-10 s/s,while receiver clock rates a

关键词： POD time synchronization clock errors elimination SLR evaluation

SIS accuracy and service performance of the BDS-3 basic system

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Science china(Physics,Mechanics & Astronomy) 2020年第6期63卷 105-116页

作者： JinPing Chen xiaogong hu ChengPan Tang {2. zhou YuFei Yang JunYang Pan hui Ren YueXin Ma QiuNing Tian bin Wu Yang Yu Beijing Satellite Navigation Center Beijing 100094China shanghai astronomical {2. Chinese Academy of SciencesShanghai 200030China shanghai Key Laboratory for Space Positioning and Navigation Shanghai 200030China

On December 2.,2.18,the basic system of the third-generation BeiDou navigation satellite system(BDS-3)completed the deployment of its constellation of 18 MEO networking satellites as well as the construction of the operation control system(OCS)and began to provide basic navigation services to users *** with BDS-2.BDS-3 aims to offer users better navigation signals and higher precision with a series of new *** example,the spaceborne atomic clock of BDS-3 is upgraded for higher performance,the Ka-band inter-satellite link is adopted for inter-satellite ranging and communication,and new B1C and B2. signals are broadcast in addition to B1I and B3I signals(compatible with BDS-2..In addition,a 9-parameter model based on a spherical harmonic function is employed for ionospheric delay *** the observation data from 18 satellites of the basic system,this paper conducts a comprehensive evaluation of the pseudorange measurement characteristics,signal-in-space(SIS)accuracy of navigation messages and global service capability of *** results indicate that the pseudorange measurement multipath effect and observation noise of BDS-3 satellites are better than those of BDS-2.additionally,with the support of inter-satellite links,the user range error(URE)of the BDS-3 satellite broadcast ephemeris is better than 10 cm,the precision of the broadcast clock parameter is better than 1.5 ns,and the SIS accuracy is better than 0.6 m *** from the traditional Klobuchar model,the BeiDou global broadcast ionospheric delay correction model(BDGIM)can provide ionospheric delay corrections better than 70%for worldwide single-frequency *** service capability evaluation of the basic system consists mainly of the accuracy improvement of the B1I and B3I signals according to BDS-2.as well as the global positioning accuracy of the new *** results prove that the BDS-3 basic system has achieved the design goal;that is,both the hori

关键词： BDS-3 SIS URE multipath effect broadcast ephemeris broadcast clock ionospheric model positioning accuracy

The Establishment And Precision Analysis Of Global Ionospheric Model Of COMPASS System

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The Establishment And Precision Analysis Of Global Ionospher...

第四届中国卫星导航学术年会

作者： Xiuqiang Gong Nan Xing shanshi zhou Yueling Cao {2. hu bin Wu shanghai astronomical {2. Chinese Academy of Sciences

Ionospheric delay is one of the main error sources affecting the positioning and timing precision of satellite navigation system for single frequency users. china’s regional satellite navigation system uses ionospheric puncture point data of monitoring stations to fit the 8 parameters of klobuchar model in geographic coordinate system,and broadcasts them to users through the navigation message which is valid for two hours. Long-term monitoring shows that this model can correct the ionospheric delay up to 74% in service area around china. Due to the lack of ionospheric measured data in the southern hemisphere and high latitudes of the northern hemisphere , this model can not guarantee the correction accuracy in equatorial belt and high latitudes. This paper improves the klobuchar model expressed in the form of 9 parameters. Not only this model can keep the ionospheric double-peak characteristic but also ensure global fitting precision. In order to obtain real-time ionospheric data outside regional monitoring network, this paper examines the precision of forecasting model based on ionosphere spherical harmonic coefficient. According to the results of comparison,the model in this paper can correct the ionospheric delay for the next 2. hours up to 72. in china. Globally, the correction accuracy reaches 70% in the north hemisphere, while 69% in the south hemisphere. As a result, the correction precision of the model is better than the model broadcasted by GPS.

关键词： COMPASS. Ionosphere. Klobuchar. Amplitude. Spherical harmonics. Magnetic symmetry

Research on Performance Evaluation of the Beidou Satellite Clock and Prediction of Satellite Clock Bias

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Research on Performance Evaluation of the Beidou Satellite C...

第七届中国卫星导航学术年会

作者： XU Xueqing zhou shanshi Shi Si {2. xiaogong zhou Yonghong shanghai astronomical {2. Chinese Academy of sciences Key Laboratory of Planetary sciences Chinese Academy of Sciences Graduate University of chinese academy of sciences

Satellite clock bias(SCB) is provided by the in orbit atomic clock, which is the key to satellite navigation system. Firstly, the time reference of the satellite navigation system is realized by the SCB, and the SCB prediction accuracy will also affect the positioning accuracy of real-time navigation users. With the development of our Beidou satellite navigation system(BDS), the performance requirement of the satellite clock and accuracy requirement of the SCB prediction is higher and higher, so this paper will study on performance evaluation of BDS atomic clock and the prediction of SCB exclusively. In order to show the results objectively and effectively, we selects two data processing centers of the Geo ForschungsZ entrum Potsdam(GBM), and SHAO Analysis Center(SHA), to obtain the same time BDS clock bias sequence as the base data, for a comparative analysis. Firstly, the performance of the atomic clock is evaluated by statistics of the Allen variance. Meanwhile, we establish the model for each SCB sequence according to the characteristic of the atomic clock, by using a combined method of least squares and auto-regressive model(LS+AR), to predict and assess the SCB with root mean square error(RMS). Results show that the performance of BDS in orbit atomic clock is stable, with the day stability in the order of 10;And the atomic clock performance is related to the SCB prediction accuracy, that is shown as better performance with higher prediction accuracy;Mean while the LS+AR method model and predict SCB series based on the performance of different atomic clocks respectively, which can improve the SCB prediction accuracy effectively.

关键词： Atomic clock performance Allen variance SCB prediction Least squares Auto-regressive model

Precise Orbit and Clock Offset Determination of LEO Navigation Satellites Based on Multi-constellation and Multi-frequency Spaceborne GNSS Data

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Precise Orbit and Clock Offset Determination of LEO Navigati...

第十四届中国卫星导航年会

作者： Junjun Yuan Ertao Liang Liqian Zhao Kai Li Chengpan Tang shanshi zhou {2. hu shanghai astronomical {2. Chinese Academy of Sciences Space Star Technology Co. Ltd. shanghai Key Laboratory of Space Navigation and Positioning Techniques Shanghai Astronomical Observatory Chinese Academy of Sciences

With massive low earth orbit(LEO) satellites, LEO navigation enhancement system is important to improve the service performance of GNSS system. The high precision orbit and clock offset calculation of LEO satellites is one key to establish the stable and reliable space-time reference. Based on GPS/BDS/GALILEO data measured by LEO navigation satellites, this paper determines the precise LEO orbit and clock offset, and evaluates the precision of LEO orbit and clock offset solution. The orbit determination accuracy using GPS(L1/L2., GPS(L1/L5), BDS(B1C/B2.), and GALILEO(E1/E5a)combination is 2.42. 2.93, 2.67, and 2.87 cm, respectively. The clock offset solution accuracy using the above four combination is 0.167, 0.194, 0.186, and0.180 ns, respectively. These results can provide high-quality product for navigation enhancement system services.

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北斗广播电文钟差模型精度评估及改善策略

测绘学报 2021年第2期50卷 181-188页

作者：巩秀强袁俊军胡小工王彬陈俊平周善石中国科学院上海天文台上海200030 中国科学院大学北京100049 上海市空间导航与定位技术重点实验室上海200030

星载原子钟是北斗卫星导航系统(BDS)的核心设备,其钟差模型是北斗广播电文的重要组成部分,模型精度直接影响BDS的服务性能。本文采用星地双向时频传递(TWSTF)钟差测量为参考,评估了BDS广播电文钟差模型精度,结果表明BDS广播电文钟差模... 详细信息

星载原子钟是北斗卫星导航系统(BDS)的核心设备,其钟差模型是北斗广播电文的重要组成部分,模型精度直接影响BDS的服务性能。本文采用星地双向时频传递(TWSTF)钟差测量为参考,评估了BDS广播电文钟差模型精度,结果表明BDS广播电文钟差模型精度优于2.ns(数据龄期小于12.h)。针对BDS广播电文钟差参数解算问题,结合BDS地面段的钟差模型解算策略,本文提出进一步提升精度的多种策略。对于1 h时长的短期预报,本文提出加权线性模型与混合区间线性模型的钟差拟合预报方法,短期预报精度可提高2.%以上;对于预报时长大于6 h的中长期预报,本文采用谱分析钟差时间序列,并根据谱分析结果构造预报模型,与简单的二次多项式模型预报相比,预报6 h精度提高13%,预报12.h平均提高了2.%;对于IGSO/MEO卫星,本文提出将TWSTF的设备时延值作为参数估算,使钟差模型在设备切换后精度提高18%。最后,利用本文提出的改进策略对2.17年1月—6月的钟差数据重新处理,获得了新的广播电文钟差模型时间序列。利用新的广播电文钟差模型进行北斗监测接收机定位,结果表明,N、E、U 3个方向精度分别提高14.2.%、2..39%、14.91%,显著提升了BDS广播电文钟差服务性能。

关键词： BDS 广播电文钟差 TWSTF 精度评估谱分析精度提升

Accuracy analyses of precise orbit determination and timing for COMPASS/Beidou-2.4GEO/5IGSO/4MEO constellation

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Accuracy analyses of precise orbit determination and timing ...

第四届中国卫星导航学术年会

作者： shanshi zhou {2. hu Jianhua zhou Junping CHEN Xiuqiang GONG Chengpan TANG bin WU Li LIU Rui GUO Feng HE Xiaojie LI Hongli TAN shanghai astronomical {2. Chinese Academy of Sciences

Up to the end of October 2.12. 14 COMPASS/Beidou-2.regional satellite navigation satellites are fully operational. Different with Global Positioning System （GPS）, the space segment of COMPASS consists of Geostationary Earth Orbit （GEO） satellites, Inclined Geosynchronous Satellite Orbit （IGSO） satellites and Medium Earth Orbit （MEO） satellites, and navigation information is provided by monitoring stations limited in regional area. Besides, attitude control mode is different for each type of satellites. The predictability of satellite attitude will make broadcast ephemeris precisely predicted. In this study, satellite telemetry data are compared with nominal attitude to assess the accuracy of satellite attitude prediction. Experiments show that the accuracy is different for each type satellites, and overall prediction accuracy is better than 1°. The analyses of pseudo-range multipath noise for receivers from different manufacturers show that the random noise characteristics is significantly for the US and European manufacturers’ receivers, and the magnitude is larger than domestic manufacturers’, but strong daily repeatability of multipath noise characteristics is displayed for domestic receivers. The accuracy of precision orbit determination （OD） for COMPASS using regional and global monitoring stations data are compared to evaluate the impact of monitoring stations’ distribution on the accuracy of satellite OD. Satellite Leaser Range （SLR） residuals are adopted to assess the satellite orbit accuracy in station line-of-sight direction. The results show that the accuracy of satellite orbit overlap is about 0.2., 1.2. and 0.6m in R/T/N direction for regional monitor network, the accuracy for MEO overlap is slightly worse than two other type satellites, and the SLR residual is better than 1m. The two-way satellite time frequency transfer （TWSTFT） observations are adopted to evaluate the accuracy of satellite clock error estimations. Experiments show that the standard d

关键词： COMPASS/Beidou-2 Satellite attitude Multi-path noise POD Timing

Fitting Method and Accuracy Analysis of Broadcast Ephemeris in Hybrid Constellation

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Fitting Method and Accuracy Analysis of Broadcast Ephemeris ...

第五届中国卫星导航学术年会

作者： Feng He xiaogong hu Li Liu hua huang shanshi zhou Shan Wu Li Gu He Zhao Xiao Liu Beijing Satellite Navigation center shanghai astronomical {2. Chinese Academy of Sciences

Broadcast ephemeris parameter is an important reflection of navigation system service performance. In hybrid constellation, GEO, IGSO and MEO satellites have different dynamic characteristics which lead to different fitting performances. In this article, the basic physical meaning of ephemeris parameters are analyzed, and the evaluation for the variation characteristics of fitting parameters is carried on. Several improved algorithms are proposed from the aspect of mathematical processing, which effectively eliminates the unsuitability in the parameter fitting of GEO. The fitting accuracy of 3 types of satellites are analyzed based on the 16‐parameter model, and then the evaluation of fitting performance is completed. It is proved in the experiments: the high accuracy can be realized for the 3 types of satellites, and even the accuracy is prior to 1cm for most time. For GEO, the accuracy can be sub‐centimeter, while the accuracy can be millimeter for IGSO and MEO satellites. In summary, the 16‐parameter model is enough to meet the centimeter level application requirement .

关键词： hybrid constellation ephemeris fitting biased estimate satellite navigation

BDS监测站坐标确定及对定轨精度的影响分析

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武汉大学学报（信息科学版） 2020年第10期45卷 1501-1507页

作者：赵立谦胡小工周善石唐成盼杨宇飞中国科学院上海天文台上海200030 中国科学院大学北京100049 信息工程大学河南郑州450001

对北斗监测站(框架点)坐标的计算方法进行探讨,提出精密单点定位和联合MGEX数据网解两种处理方案确定北斗地面监测网各站在国际地球参考架下的精密坐标。利用北斗观测数据对两种方案进行验证,特别分析了地面监测网各站坐标精化对北斗导... 详细信息

对北斗监测站(框架点)坐标的计算方法进行探讨,提出精密单点定位和联合MGEX数据网解两种处理方案确定北斗地面监测网各站在国际地球参考架下的精密坐标。利用北斗观测数据对两种方案进行验证,特别分析了地面监测网各站坐标精化对北斗导航卫星区域网定轨精度的提升。初步计算结果表明:精密单点定位处理方案得到的各地面监测站坐标水平和高程的重复性分别为2.3 cm和3.4 cm,联合MGEX北斗数据网解处理方案得到的坐标水平和高程重复性分别为0.8 cm和2.2.cm。利用网解方案对监测站坐标进行更新后:IGSO(inclined geosynchronous orbit)卫星3D重叠弧段精度平均提升15.4%,MEO(medium earth orbit)卫星3D重叠弧段精度平均提升2..8%;北斗二号卫星平均激光检核残差由0.39 m降至0.2. m,平均精度提升38%;北斗三号卫星平均激光检核残差由0.2. m降至0.18 m,平均精度提升2.%。

关键词：北斗监测站精密单点定位网解区域网定轨精度重复性