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1.
Zhouzheng Gao Tuan Li Hongping Zhang Maorong Ge Harald Schuh 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(9):2393-2405
Since China’s BeiDou satellite navigation system (BDS) began to provide regional navigation service for Asia-Pacific region after 2012, more new generation BDS satellites have been launched to further expand BDS’s coverage to be global. In this contribution, precise positioning models based on BDS and the corresponding mathematical algorithms are presented in detail. Then, an evaluation on BDS’s real-time dynamic positioning and navigation performance is presented in Precise Point Positioning (PPP), Real-time Kinematic (RTK), Inertial Navigation System (INS) tightly aided PPP and RTK modes by processing a set of land-borne vehicle experiment data. Results indicate that BDS positioning Root Mean Square (RMS) in north, east, and vertical components are 2.0, 2.7, and 7.6?cm in RTK mode and 7.8, 14.7, and 24.8?cm in PPP mode, which are close to GPS positioning accuracy. Meanwhile, with the help of INS, about 38.8%, 67.5%, and 66.5% improvements can be obtained by using PPP/INS tight-integration mode. Such enhancements in RTK/INS tight-integration mode are 14.1%, 34.0%, and 41.9%. Moreover, the accuracy of velocimetry and attitude determination can be improved to be better than 1?cm/s and 0.1°, respectively. Besides, the continuity and reliability of BDS in both PPP and RTK modes can also be ameliorated significantly by INS during satellite signal missing periods. 相似文献
2.
利用广播星历计算导航卫星的速度向量是GNSS高精度实时测速的必要条件.本文分析了仅以卫星位置向量为观测量的北斗广播星历的速度计算精度.从广播星历拟合过程出发,推导了北斗18参数模型的速度向量计算公式.基于北斗13颗在轨卫星一年的实际轨道数据,分析了全年广播星历计算卫星速度向量的精度.结果表明,利用18参数模型计算的速度误差最大在10-4m·-1量级;在相同拟合时段条件下,地球静止轨道（GEO）和倾斜地球同步轨道（IGSO）卫星的速度精度相当,高于中圆地球轨道（MEO）卫星.通过对位置残差序列分析,得出位置残差误差较小且变化趋势平稳是广播星历计算速度精度较高的原因.分析和计算结果验证了仅用位置观测量拟合北斗广播星历算法的有效性. 相似文献
3.
用户测距误差（URE）与用户设备误差（UEE）是影响定位精度的主要因素.民航是北斗系统的高端用户,监测其对民航机场的覆盖性和服务性能十分必要.本文根据华东、华南、华北、西北地区4个民航机场观测站的北斗实测数据,分析了各机场卫星的可见性.根据URE的解算方法、电离层修正模型、对流层修正模型以及定位精度的评估方法,给出了对应的性能评估结果.研究发现：可见星数均在6～14颗,满足定位要求; 95%置信度下,电离层延迟优于7.50m,对流层延迟优于13.28m,地球静止轨道卫星（GEO）、倾斜地球同步轨道卫星（IGSO）、中圆轨道卫星（MEO）卫星的URE值分别优于2.36m,1.72m,2.59m,满足北斗规范的要求;95%置信度下,定位精度水平方向优于3.63m,垂直方向优于6.98m.结果表明北斗系统在民航机场监测站的覆盖性及服务性能良好. 相似文献
4.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(1):221-234
Due to the limited number and uneven distribution globally of Beidou Satellite System (BDS) stations, the contributions of BDS to global ionosphere modeling is still not significant. In order to give a more realistic evaluation of the ability for BDS in ionosphere monitoring and multi-GNSS contributions to the performance of Differential Code Biases (DCBs) determination and ionosphere modeling, we select 22 stations from Crustal Movement Observation Network of China (CMONOC) to assess the result of regional ionospheric model and DCBs estimates over China where the visible satellites and monitoring stations for BDS are comparable to those of GPS/GLONASS. Note that all the 22 stations can track the dual- and triple-frequency GPS, GLONASS, and BDS observations. In this study, seven solutions, i.e., GPS-only (G), GLONASS-only (R), BDS-only (C), GPS + BDS (GC), GPS + GLONASS (GR), GLONASS + BDS (RC), GPS + GLONASS + BDS (GRC), are used to test the regional ionosphere modeling over the experimental area. Moreover, the performances of them using single-frequency precise point positioning (SF-PPP) method are presented. The experimental results indicate that BDS has the same ionospheric monitoring capability as GPS and GLONASS. Meanwhile, multi-GNSS observations can significantly improve the accuracy of the regional ionospheric models compared with that of GPS-only or GLONASS-only or BDS-only, especially over the edge of the tested region which the accuracy of the model is improved by reducing the RMS of the maximum differences from 5–15 to 2–3 TECu. For satellite DCBs estimates of different systems, the accuracy of them can be improved significantly after combining different system observations, which is improved by reducing the STD of GPS satellite DCB from 0.243 to 0.213, 0.172, and 0.165 ns after adding R, C, and RC observations respectively, with an increment of about 12.3%, 29.4%, and 32.2%. The STD of GLONASS satellite DCB improved from 0.353 to 0.304, 0.271, and 0.243 ns after adding G, C, and GC observations, respectively. The STD of BDS satellite DCB reduced from 0.265 to 0.237, 0.237 and 0.229 ns with the addition of G, R and GR systems respectively, and increased by 10.6%, 10.4%, and 13.6%. From the experimental positioning result, it can be seen that the regional ionospheric models with multi-GNSS observations are better than that with a single satellite system model. 相似文献
5.
北斗系统作为我国自行研制的导航系统,具有独特的混合星座特性,其反射事件在海洋上的空间分布和覆盖性能的研究成果较少。针对上述问题,模拟了北斗三号(Beidou System 3,BDS3)以及全球定位系统(Global Positioning System,GPS)空间星座,模拟不同性能参数的低轨接收卫星,在此仿真系统的基础上,计算反射事件在各仿真场景下的海洋覆盖率以及同时发生反射事件的卫星数量。结果表明:BDS3与GPS相比具有更大的反射事件海洋覆盖率,覆盖性能更优;仿真周期7天与1天相比,前者卫星产生的反射事件海洋覆盖率约为后者5倍;低轨道卫星(Low Earth Orbit,LEO)轨道高度越高,天线波束角度越大,反射事件海洋覆盖率越大; 3颗LEO卫星下同时发生反射事件卫星数的平均值约为单颗LEO卫星的3倍。可通过设计多星组网来提高反射事件海洋覆盖率。研究结果对星载反射技术海洋遥感应用方面有一定的参考价值。 相似文献
6.
针对目前高轨GPS信号可用性差及定位精度低的特点, 对GPS/北斗组合系统的 高轨卫星定位技术进行研究, 对比分析了单GPS系统与GPS/北斗组合系统的卫 星可见性和几何精度因子. 结果表明, GPS/北斗组合系统比单GPS系统的卫星可 见性好, 且定位精度高. 同时通过提出在星载接收机上采用高精度原子钟, 可实现三星定位, 降低对接收机的技术要求. 相似文献
7.
全球导航卫星系统反射测量（GNSS-R）是一种新兴的海面风速遥感技术,对GNSS-R反演风速进行详细定量分析是该技术从科学研究走向业务应用的必要条件。 以气旋全球导航卫星系统（CYGNSS）的风速数据为例,利用时空匹配的浮标风速和欧洲中期天气预报中心（ECMWF）的预报风速数据,详细分析了CYGNSS遥感风速的气候态特征和时空分布特征。基于三配对数据分析方法,阐明了CYGNSS遥感风速的固有误差,并提出了相应的风速标定系数。研究表明：GYGNSS的中低风速（w <10 m·s–1）精度较好,但高风速的误差显著增大;风速误差具有良好的时间一致性,但呈现明显的空间分布不均匀现象;总体而言,CYGNSS风速的固有误差约为1.79 m·s–1。研究结果一方面可为CYGNSS风速数据的业务应用提供参考,另一方面也为进一步标定CYGNSS的反射测量信号提供依据。 相似文献
8.
北斗卫星导航信号采用三个频点工作,可以利用伪距双频组差方法解算电离层电子含量,为实时监视中国区域电离层变化提供新的技术手段.中国中低纬度处于电离层赤道异常变化区,在北纬20°±5°区域时常发生较大梯度的电离层变化.利用北斗实时多频伪距和相位观测数据,采用相位平滑伪距方法计算电离层穿刺点电子含量,分析通过北斗系统GEO卫星监测的电离层周日变化特性;采用多面函数方法拟合中国区域1°×1°分辨率的电离层延迟量,每5min绘制一幅中国区域电离层图,观测区域所有电离层穿刺点拟合残差RMS为2.778TECU;分析北斗系统实时监测中国区域电离层异常情况,当发生电离层异常变化时,相邻两天的VTEC（Vertical Total Electronic Content）峰值相差约60TECU. 相似文献
9.
Hui Lei ZhiGang Li XuHai Yang WenJun Wu Xuan Cheng Ying Yang ChuGang Feng 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
A new strategy of precise orbit determination (POD) for GEO (Geostationary Earth Orbit) satellite using SATRE (SAtellite Time and Ranging Equipment) is presented. Two observation modes are proposed and different channels of the same instruments are used to construct different observation modes, one mode receiving time signals from their own station and the other mode receiving time signals from each other for two stations called pairs of combined observations. Using data from such a tracking network in China, the results for both modes are compared. The precise orbit determination for the Sino-1 satellite using the data from 6 June 2005 to 13 June 2005 has been carried out in this work. The RMS (Root-Mean-Square) of observing residuals for 3-day solutions with the former mode is better than 9.1 cm. The RMS of observing residuals for 3-day solutions with the latter mode is better than 4.8 cm, much better than the former mode. Orbital overlapping (3-day orbit solution with 1-day orbit overlap) tests show that the RMS of the orbit difference for the former mode is 0.16 m in the radial direction, 0.53 m in the along-track direction, 0.97 m in the cross-track direction and 1.12 m in the 3-dimension position and the RMS of the orbit difference for the latter mode is 0.36 m in the radial direction, 0.89 m in the along-track direction, 1.18 m in the cross-track direction and 1.52 m in the 3-dimension position, almost the same as the former mode. All the experiments indicate that a meter-level accuracy of orbit determination for geostationary satellite is achievable. 相似文献
10.
在信号传播与接收的过程中对电离层延迟进行改正可以提升卫星导航定位的精度, 电离层经验模型, 如国际参考电离层(International Reference Ionosphere, IRI)模型和IRI-Plas (IRI Extended to Plasmasphere)模型在估计电离层参数时得到广泛应用. 基于太阳活动低年2021年全球135个GNSS站的双频观测数据, 提取了垂直总电子含量(VTEC)和倾斜总电子含量(STEC)作为评价基准, 评估了同化GIM TEC数据的IRI-Plas 2020模型、未同化外部TEC的IRI-Plas 2020模型和IRI-2020模型. 针对不同模型与GNSS观测值之间的精度差异做了详细评估与分析, 分析了电离层纬度变化、日变化与季节变化规律, 探究了两种模型在不同地磁情况下的精度表现. 结果表明, 两种模型均能很好地表现电离层特征, 其中同化GIM TEC的IRI-Plas模型值精度最高, 由于模型计算高度范围的限制, 导致IRI模型值偏低, 未同化外部TEC的IRI-Plas模型值偏高. 同时, 两种模型的误差都表现出纬度变化, 通常随着纬度的增加而下降, 这些变化还显示出季节性趋势. 相似文献
11.
利用全球卫星导航系统(GNSS)进行导航定位具有全球、全天候、实时和高精度的优点,应用于高地球轨道(HEO)卫星的定位,能够提供精确的轨道和姿态确定,并且可以克服目前主要利用地面测控系统对HEO卫星进行定位的设备复杂、投资高等缺点,使得自主导航成为可能.本文对利用GNSS的高轨卫星定位相关技术进行了研究,分析了单一GNSS系统和多个GNSS组合系统的卫星可见性、动态性和几何精度因子(GDOP).通过仿真分析表明,利用组合GNSS系统并通过提高GNSS接收机灵敏度的方法,可以解决GNSS进行HEO卫星定位的相关问题,并能保证HEO卫星定位精度的要求. 相似文献
12.
Wendong Meng Haifeng Zhang Peicheng Huang Jie Wang Zhongping Zhang Ying Liao Yang Ye Wei Hu Yuanming Wang Wanzhen Chen Fumin Yang Ivan Prochazka 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
High-precision time synchronization between satellites and ground stations plays the vital role in satellite navigation system. Laser time transfer (LTT) technology is widely recognized as the highest accuracy way to achieve time synchronization derived from satellite laser ranging (SLR) technology. Onboard LTT payload has been designed and developed by Shanghai Astronomical Observatory, and successfully applied to Chinese Beidou navigation satellites. By using the SLR system, with strictly controlling laser firing time and developing LTT data processing system on ground, the high precise onboard laser time transfer experiment has been first performed for satellite navigation system in the world. The clock difference and relative frequency difference between the ground hydrogen maser and space rubidium clocks have been obtained, with the precision of approximately 300 ps and relative frequency stability of 10E−14. This article describes the development of onboard LTT payload, introduces the principle, system composition, applications and LTT measuring results for Chinese satellite navigation system. 相似文献
13.
北斗卫星导航系统(BDS)中GEO卫星频繁的轨道机动对高精度、实时不间断的导 航服务需求提出了更高要求, 如何在短弧跟踪条件下提高GEO卫星轨道快速 恢复能力, 是提升导航系统服务精度的关键因素. 针对该问题, 本文提出了基 于机动力模型的动力学定轨方法, 尝试利用高精度的C波段转发式测距数据, 辅 以机动期间的遥测遥控信息建立机动力模型, 联合轨控前后的观测数据进行动 力学长弧定轨. 利用BDS中GEO卫星实测数据进行了定轨试验与分析, 结果表明, 恢复期间需要采用解算机动推力的定轨方法, 联合机动前、机动期间和机 动后4h数据定轨的轨道位置精度在20m量级, 径向精度优于2.5m. 该方 法克服了短弧跟踪条件下动力学法定轨和单点定位中的诸多问题, 提供了解决 GEO卫星机动后轨道快速恢复问题的技术方法. 相似文献
14.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(1):518-528
Due to the special geographical location and extreme climate environment, the polar regions (Antarctic and Arctic) have an important impact on global climate change. Atmospheric weighted mean temperature (Tm) is a crucial parameter in the retrieval of precipitable water vapor (PWV) from the zenith wet delay (ZWD) of ground-based Global Navigation Satellite System (GNSS) signal propagation. In this paper, the correlation between weighted mean temperature and surface temperature (Ts) is studied firstly. It is shown that the correlation coefficients between Tm and Ts are 0.93 in the Antarctic and 0.94 in the Arctic. The linear regression Tm model and quadratic function Tm model of the Antarctic and the Arctic are established respectively using the radiosonde profiles of 12 stations in the Antarctic and 58 stations in the Arctic from 2008 to 2015. The accuracies of the linear regression Tm model, the quadratic function Tm model and GPT2w Tm model which is a state-of-the-art global Tm model are verified using the radiosonde profiles from 2016 to 2018 in the Antarctic and Arctic. Root Mean Square (RMS) errors of the linear regression Tm model, the quadratic function Tm model and GPT2w Tm model in the Antarctic are 3.07 K, 2.87 K and 4.32 K respectively, and those in the Arctic are 3.53 K, 3.38 K and 4.82 K, which indicates that the quadratic function Tm model has a higher accuracy compared to linear regression Tm model, and the accuracies of the two regional Tm models are better than that of GPT2w Tm model in the polar regions. In order to better evaluate the accuracy of Tm in the PWV retrieval, the PWV values of radiosondes are used for comparisons as the reference value. The RMS errors of PWV derived from the two Tm models are similar for 1.28 mm in the Antarctic and 1 mm in the Arctic respectively. In addition, the spatial and temporal variation characteristics of Tm are analyzed in the polar regions by spectral analysis of Tm data using fast Fourier transform. The results show that the Tm has obvious seasonality and annual periodicity in the polar regions, and the maximum difference between warm season and cold season is about 63 K. After comparing and analyzing the influences of latitude, longitude and elevation on the Tm in the polar regions, it is found that latitude and elevation have a greater influence on the Tm than the longitude. As the latitude and elevation increase, the Tm decreases, and vice versa in the polar regions. 相似文献
15.
GRO（Global Navigation Satellite System Radio Occultation）和LRO（Low Earth Orbit Radio Occultation）联合组网探测地球大气是无线电掩星探测技术的主要发展方向.本文根据掩星事件的数学判据,仿真分析了LEO卫星主要轨道参数对GRO和LRO掩星事件数量和全球分布情况的影响.研究表明：卫星轨道越低GRO掩星事件越多;轨道倾角在30°和75°之间时,GRO掩星事件较多,全球覆盖率也较大;利用极轨卫星进行LRO掩星探测时,LRO掩星事件较均匀地分布在各纬度带.研究成果对GRO和LRO联合星座设计具有参考价值. 相似文献
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17.
星间时标误差的自主测量对于中国自主研发地球重力卫星具有重要意义. 提出利用双向时间传递法实现重力卫星时标误差的自主测量, 设计了测量方案, 建立了包含卫星运动导致的链路非对称、电离层效应、设备零值以及随机测时误差在内的测量模型. 结合地球重力卫星相关特性, 分析了时标误差测量中各误差源的影响及相应的误差校正方法. 以GRACE重力卫星为例, 利用提出的方法和校正措施, 星间时标误差自主测量精度可以达到0.62ns, 其中误差主要来自系统零值标定误差和随机测时误差. 相似文献
18.
Rui Tu Hongping Zhang Maorong Ge Guanwen Huang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
This paper proposes a method of real-time monitoring and modeling the ionospheric Total Electron Content (TEC) by Precise Point Positioning (PPP). Firstly, the ionospheric TEC and receiver’s Differential Code Biases (DCB) are estimated with the undifferenced raw observation in real-time, then the ionospheric TEC model is established based on the Single Layer Model (SLM) assumption and the recovered ionospheric TEC. In this study, phase observations with high precision are directly used instead of phase smoothed code observations. In addition, the DCB estimation is separated from the establishment of the ionospheric model which will limit the impacts of the SLM assumption impacts. The ionospheric model is established at every epoch for real time application. The method is validated with three different GNSS networks on a local, regional, and global basis. The results show that the method is feasible and effective, the real-time ionosphere and DCB results are very consistent with the IGS final products, with a bias of 1–2 TECU and 0.4 ns respectively. 相似文献