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1.
北斗三号卫星之间及卫星与锚固站之间在Ka频段的伪距测量为其提供了一种不依赖于地面监测站的独立定轨和时间同步能力。本文针对星间链路分时测量的特点,采用分段一次多项式对卫星钟差进行建模,直接利用原始的星地和星间单程Ka伪距实现一体化定轨和时间同步并同时解算锚固站设备硬件时延。利用北斗三号8颗卫星和2个锚固站的实测Ka伪距数据进行验证,结果表明:在利用导航电文的预报钟速信息进行修正的情况下,星间Ka伪距残差RMS为0.052 m;R方向卫星轨道确定和预报精度(RMS)分别为0.016、0.033 m;卫星钟差估计和预报精度(95%)分别为0.038、0.992 ns;解算得到的锚固站收发设备时延之和的稳定性优于0.5 ns。试验还展示了该方法的适应能力:在没有预报钟速信息的极端情况下,虽然星间Ka伪距残差RMS增大了242%,但R方向轨道确定和预报精度仍分别达到0.021、0.041 m,钟差估计和预报精度分别达到0.040、1.092 ns。 相似文献
2.
星间单程伪距联合监测站数据确定北斗三号卫星轨道和钟差 总被引：1，自引：1，他引：0
提出利用原始单程星间伪距数据联合地面监测站载波相位和伪距数据同时确定北斗卫星轨道和钟差的方法。该方法引入时间窗概念,用多项式表示卫星钟差,从而能够直接对非同时观测的原始单程伪距数据进行平差处理。收集中国境内的6个iGMAS监测站和星间测距数据对北斗三号卫星进行轨道和钟差确定试验。结果表明,轨道重叠段互差在R、T和N方向的RMS分别为0.078、0.321和0.375 m,钟差重叠段互差的RMS和STD分别达到0.589和0.519 ns。相比于仅用国内监测站数据的结果,轨道和钟差的改进幅度分别超过80%和60%。星间链路单程伪距残差的平均RMS为0.083 m,星间链路信号发射和接收设备时延偏差估值的平均稳定度分别为0.53和0.72 ns。 相似文献
3.
《测绘科学技术学报》2013,(6)
星间链路收发天线的时延零值是星间测距时延的组成部分,其标定精度影响星间的测距精度,从而影响编队飞行的星座系统性能。提出的星间链路天线时延标定方法,利用星座系统配置多个星间链路天线特点,取待测天线两两组合,通过星间链路发射机和星间链路接收机组成测试系统,测量组合时延。根据各组合时延值、测试通道的零值校准结果以及收发天线的空间传播时延,通过数据处理得到各测试天线收发星间链路信号时的绝对时延。提出的测试方法不需要专门的校准天线,采用与星间链路传输信号体制一致的测试信号,测试结果能真实反映星间链路信号传输时延。试验系统的测试结果表明,采用提出方法的天线时延标定精度可以优于0.5 ns。 相似文献
4.
5.
为提升区域地面监测站条件下北斗卫星定轨精度,面向日益丰富的北斗星载数据和即将实现的星间链路技术,提出了联合运用地面监测站数据、低轨卫星星载数据与星间链路数据的北斗卫星精密定轨方法。讨论了低轨卫星星载数据与星间链路数据增强对于导航卫星精密定轨的影响,重点从低轨卫星数量、轨位分布及星间链路等方面进行了仿真分析。结果表明:加入少量低轨卫星与区域监测站联合定轨即可显著提高导航卫星定轨精度约73%,钟差解算精度略有改进但不明显;同等数量且均匀分布的低轨星座,其轨位分布对联合定轨精度影响不大;加入星间链路数据可大幅提升导航卫星定轨精度,且改进效率高于低轨卫星。 相似文献
6.
介绍了卫星信号内部时延的定义以及在GPS导航电文NAV和CNAV中所给出的各种时延差参数,推导了采用不同的卫星信号测距时应采用的各种卫星钟差模型。 相似文献
7.
《测绘科学》2020,(4)
针对北斗二号系统和北斗三号系统导航电文播发现状,该文从导航电文结构、导航电文内容和播发方式等方面对二者间的差异进行了比对分析,着重比较分析了卫星星历参数、卫星钟差钟差、数据有效性标识、设备群延迟参数、设备延迟参数、电离层改正、完好性等导航电文参数,并结合导航电文实际应用,给出了广播星历拟合精度、卫星钟差拟合精度、系统定位精度评估结果。结果表明:北斗卫星广播星历拟合残差为厘米级,18参数广播星历拟合精度略优于16参数的拟合精度;加入星间链路钟差后,MEO卫星的钟差测定精度虽与仅星地观测的钟差精度基本相当,但明显提高了卫星钟差预报精度;北斗二号与北斗三号联合定位精度较仅北斗二号卫星定位精度有所提升。 相似文献
8.
目前,BDS-3卫星上已全部搭载星间链路设备,可利用星间双向测量数据分离卫星相对钟差和相对几何距离解耦卫星轨道和钟差,再把星间距离作为观测量结合地面测量数据进行星地星间联合定轨。人卫激光测距(SLR)技术不受载波相位模糊度、钟差等因素的影响,数据处理过程相对于GNSS技术的数据处理更简单,可以作为一种独立于GNSS观测技术的测量手段。所有BDS卫星上已搭载激光角反射器,因此本文利用2020年1月北斗星间链路数据及少量SLR数据对11颗BDS-3卫星(MEO/IGSO/GEO)进行联合精密定轨试验。分析结果表明,基于SLR和星间链路的3类轨道类型的BDS-3卫星定轨精度相当,轨道精度径向为4.2 cm,三维精度为30.2 cm;卫星轨道预报12 h和24 h MEO卫星三维精度约40.0 cm,IGSO三维精度优于60.0 cm;GEO卫星三维精度约1.0 m。在精密定轨的同时解算地球自转参数(ERP),由于激光数据量少,极移精度约3.0 mas,日长变化精度为0.35 ms。利用少量SLR观测数据和星间链路测量数据联合可以实现导航卫星的高精度定轨,如果能够对BDS卫星加强激光观测,有助于提升轨道精度,为BDS自主可控空间基准参数解算提供参考。 相似文献
9.
多星座数据融合处理时,由于接收机钟差和信号传播延迟的影响,导致信号发射时刻的卫星位置不能精确求定。在定位解算里,可以通过星间差分消除与光速有关的接收机钟差影响,然而与卫星径向速度有关的接收机钟差项却得不到消除。该文详细分析了多星座接收机不同钟差值的产生原因,推导了卫星径向速度对站星距的影响,提出了一种针对多星座的单基准站接收机钟差估计方法,通过统一修正各星座卫星位置,有效消除了与卫星速度有关的接收机钟差项的误差,并且适用于存在1ms时钟跳跃的接收机,实现多星座融合的高精度定位。 相似文献
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11.
A technique for obtaining clock measurements from individual GNSS satellites at short time intervals is presented. The methodology developed in this study allows for accurate satellite clock stability analysis without an ultra-stable clock at the ground receiver. Variations in the carrier phase caused by the satellite clock are isolated using a combination of common GNSS carrier-phase processing techniques. Furthermore, the white phase variations caused by the thermal noise of the collection and processing equipment are statistically modeled and removed, allowing for analysis of clock performance at subsecond intervals. Allan deviation analyses of signals collected from GPS and GLONASS satellites reveal distinct intervals of clock noise for timescales less than 100 s. The clock data collected from GPS Block IIA, IIR, IIR-M, and GLONASS satellites reveal similar stability performance at time periods greater than 20 s. The GLONASS clock stability in the 0.6–10 s range, however, is significantly worse than GPS. Applications that rely on ultra-stable clock behavior from the GLONASS satellites at these timescales may therefore require high-rate corrections to estimate and remove oscillator-based errors in the carrier phase. 相似文献
12.
在GNSS高精度数据处理中,卫星钟差往往是决定结果精度的核心因素之一。采用20 Hz的双频观测数据对GNSS星载原子钟0.05~100 s平滑时间下的短期稳定性进行分析,通过星间单差的方法消除接收机钟差,采用无电离层组合及夜间观测避免电离层高阶项短期变化的影响,同时采用经验模型和映射函数来进行对流层延迟改正。通过Lag 1自相关函数分析了影响GNSS卫星钟稳定性的主要噪声类型,并使用阿伦方差计算分析GPS、GLONASS及BDS各自系统内不同卫星组合之间的钟差。结果表明,GPS、GLONASS及BDS系统钟差稳定性0.05秒稳均可达到10-10量级,秒稳可达10-11量级。可以认定,GPS、GLONASS及BDS在短期内的稳定性量级相当,从而验证了基于星间单差的BDS掩星数据处理方案的可行性。 相似文献
13.
Chinese BeiDou navigation satellite system is in official service as a regional constellation with five geostationary earth orbit (GEO) satellites, five inclined geosynchronous satellite orbit (IGSO) satellites and four medium earth orbit (MEO) satellites. There are mainly two methods for precise orbit determination of the BeiDou constellation found in the current literatures. One is the independent single-system method, where only BeiDou observations are used without help from other GNSS systems. The other is the two-step GPS-assisted method where in the first step, GPS data are used to resolve some common parameters, such as station coordinates, receiver clocks and zenith tropospheric delay parameters, which are then introduced as known quantities in BeiDou processing in the second step. We conduct a thorough performance comparison between the two methods. Observations from the BeiDou experimental tracking stations and the IGS Multi-GNSS Experiment network from January 1 to March 31, 2013, are processed with the Positioning and Navigation Data Analyst (PANDA) software. The results show that for BeiDou IGSO and MEO satellites, the two-step GPS-assisted method outperforms the independent single-system method in both internal orbit overlap precision and external satellite laser ranging validation. For BeiDou GEO satellites, the two methods show close performances. Zenith tropospheric delays estimated from the first method are very close to those estimated from GPS precise point positioning in the second method, with differences of several millimeters. Satellite clock estimates from the two methods show similar performances when assessing the stability of the BeiDou on board clocks. 相似文献
14.
Initial results of centralized autonomous orbit determination of the new-generation BDS satellites with inter-satellite link measurements 总被引：3，自引：0，他引：3
Chengpan Tang Xiaogong Hu Shanshi Zhou Li Liu Junyang Pan Liucheng Chen Rui Guo Lingfeng Zhu Guangming Hu Xiaojie Li Feng He Zhiqiao Chang 《Journal of Geodesy》2018,92(10):1155-1169
Autonomous orbit determination is the ability of navigation satellites to estimate the orbit parameters on-board using inter-satellite link (ISL) measurements. This study mainly focuses on data processing of the ISL measurements as a new measurement type and its application on the centralized autonomous orbit determination of the new-generation Beidou navigation satellite system satellites for the first time. The ISL measurements are dual one-way measurements that follow a time division multiple access (TDMA) structure. The ranging error of the ISL measurements is less than 0.25 ns. This paper proposes a derivation approach to the satellite clock offsets and the geometric distances from TDMA dual one-way measurements without a loss of accuracy. The derived clock offsets are used for time synchronization, and the derived geometry distances are used for autonomous orbit determination. The clock offsets from the ISL measurements are consistent with the L-band two-way satellite, and time–frequency transfer clock measurements and the detrended residuals vary within 0.5 ns. The centralized autonomous orbit determination is conducted in a batch mode on a ground-capable server for the feasibility study. Constant hardware delays are present in the geometric distances and become the largest source of error in the autonomous orbit determination. Therefore, the hardware delays are estimated simultaneously with the satellite orbits. To avoid uncertainties in the constellation orientation, a ground anchor station that “observes” the satellites with on-board ISL payloads is introduced into the orbit determination. The root-mean-square values of orbit determination residuals are within 10.0 cm, and the standard deviation of the estimated ISL hardware delays is within 0.2 ns. The accuracy of the autonomous orbits is evaluated by analysis of overlap comparison and the satellite laser ranging (SLR) residuals and is compared with the accuracy of the L-band orbits. The results indicate that the radial overlap differences between the autonomous orbits are less than 15.0 cm for the inclined geosynchronous orbit (IGSO) satellites and less than 10.0 cm for the MEO satellites. The SLR residuals are approximately 15.0 cm for the IGSO satellites and approximately 10.0 cm for the MEO satellites, representing an improvement over the L-band orbits. 相似文献
15.
Daniela Thaller Rolf Dach Manuela Seitz Gerhard Beutler Maria Mareyen Bernd Richter 《Journal of Geodesy》2011,85(5):257-272
Satellite Laser Ranging (SLR) observations to Global Navigation Satellite System (GNSS) satellites may be used for several
purposes. On one hand, the range measurement may be used as an independent validation for satellite orbits derived solely
from GNSS microwave observations. On the other hand, both observation types may be analyzed together to generate a combined
orbit. The latter procedure implies that one common set of orbit parameters is estimated from GNSS and SLR data. We performed
such a combined processing of GNSS and SLR using the data of the year 2008. During this period, two GPS and four GLONASS satellites
could be used as satellite co-locations. We focus on the general procedure for this type of combined processing and the impact
on the terrestrial reference frame (including scale and geocenter), the GNSS satellite antenna offsets (SAO) and the SLR range
biases. We show that the combination using only satellite co-locations as connection between GNSS and SLR is possible and
allows the estimation of SLR station coordinates at the level of 1–2 cm. The SLR observations to GNSS satellites provide the
scale allowing the estimation of GNSS SAO without relying on the scale of any a priori terrestrial reference frame. We show
that the necessity to estimate SLR range biases does not prohibit the estimation of GNSS SAO. A good distribution of SLR observations
allows a common estimation of the two parameter types. The estimated corrections for the GNSS SAO are 119 mm and −13 mm on
average for the GPS and GLONASS satellites, respectively. The resulting SLR range biases suggest that it might be sufficient
to estimate one parameter per station representing a range bias common to all GNSS satellites. The estimated biases are in
the range of a few centimeters up to 5 cm. Scale differences of 0.9 ppb are seen between GNSS and SLR. 相似文献
16.
分析了 目前广播星历精度评估中存在的问题,详细论述了广播星历精度评估过程中对精密星历进行天线相位中心改正的取值方法,提出了利用单颗星单日钟差均值作二次差对广播星历钟差的系统性偏差进行改正的方法.选取2019-09-01-2019-11-01 共计62天的多模 GNSS 实验(multi-GNSS experiment,... 相似文献
17.
Xiaopeng Gong Shengfeng Gu Yidong Lou Fu Zheng Maorong Ge Jingnan Liu 《Journal of Geodesy》2018,92(7):797-809
Global navigation satellite systems (GNSS) are acting as an indispensable tool for geodetic research and global monitoring of the Earth, and they have been rapidly developed over the past few years with abundant GNSS networks, modern constellations, and significant improvement in mathematic models of data processing. However, due to the increasing number of satellites and stations, the computational efficiency becomes a key issue and it could hamper the further development of GNSS applications. In this contribution, this problem is overcome from the aspects of both dense linear algebra algorithms and GNSS processing strategy. First, in order to fully explore the power of modern microprocessors, the square root information filter solution based on the blocked QR factorization employing as many matrix–matrix operations as possible is introduced. In addition, the algorithm complexity of GNSS data processing is further decreased by centralizing the carrier-phase observations and ambiguity parameters, as well as performing the real-time ambiguity resolution and elimination. Based on the QR factorization of the simulated matrix, we can conclude that compared to unblocked QR factorization, the blocked QR factorization can greatly improve processing efficiency with a magnitude of nearly two orders on a personal computer with four 3.30 GHz cores. Then, with 82 globally distributed stations, the processing efficiency is further validated in multi-GNSS (GPS/BDS/Galileo) satellite clock estimation. The results suggest that it will take about 31.38 s per epoch for the unblocked method. While, without any loss of accuracy, it only takes 0.50 and 0.31 s for our new algorithm per epoch for float and fixed clock solutions, respectively. 相似文献
18.
Dae Hee Won Eunsung Lee Moonbeom Heo Sangkyung Sung Jiyun Lee Young Jae Lee 《GPS Solutions》2014,18(2):177-187
In urban canyons, buildings and other structures often block the line of sight of visible Global Navigation Satellite System (GNSS) satellites, which makes it difficult to obtain four or more satellites to provide a three-dimensional navigation solution. Previous studies on this operational environment have been conducted based on the assumption that GNSS is not available. However, a limited number of satellites can be used with other sensor measurements, although the number is insufficient to derive a navigation solution. The limited number of GNSS measurements can be integrated with vision-based navigation to correct navigation errors. We propose an integrated navigation system that improves the performance of vision-based navigation by integrating the limited GNSS measurements. An integrated model was designed to apply the GNSS range and range rate to vision-based navigation. The possibility of improved navigation performance was evaluated during an observability analysis based on available satellites. According to the observability analysis, each additional satellite decreased the number of unobservable states by one, while vision-based navigation always has three unobservable states. A computer simulation was conducted to verify the improvement in the navigation performance by analyzing the estimated position, which depended on the number of available satellites; additionally, an experimental test was conducted. The results showed that limited GNSS measurements can improve the positioning performance. Thus, our proposed method is expected to improve the positioning performance in urban canyons. 相似文献
19.
Due to the limited frequency stability and poor accuracy of typical quartz oscillators built-in GNSS receivers, an additional receiver clock error has to be estimated in addition to the coordinates. This leads to several drawbacks especially in kinematic applications: At least four satellites in view are needed for navigation, high correlations between the clock estimates and the up-coordinates. This situation can be improved distinctly when connecting atomic clocks to GNSS receivers and modeling their behavior in a physically meaningful way (receiver clock modeling). Recent developments in miniaturizing atomic clocks result in so-called chip-scale atomic clocks and open up the possibility of using stable atomic clocks in GNSS navigation. We present two different methods of receiver clock modeling, namely in an extended Kalman filter and a sequential least-squares adjustment for code-based GNSS navigation using three different miniaturized atomic clocks. Using the data of several kinematic test drives, the benefits of clock modeling for GPS navigation solutions are assessed: decrease in the noise of the up-coordinates by up to 69 % to 20 cm level, decrease in minimal detectable biases by 16 %, and elimination of spikes and subsequently decrease in large position errors (35 %). Hence, a more robust position is obtained. Additionally, artificial partial satellite outages are generated to demonstrate position solutions with only three satellites in view. 相似文献
20.
针对大型桥梁桥塔与基站高程差异较大,残余对流层延迟成为影响全球卫星导航系统(GNSS)监测成功率与精度的主要因素之一。该文基于随机过程理论,对桥梁监测GNSS残余对流层湿延迟进行参数估计,有效地提高了桥梁塔顶监测GNSS模糊度固定率。通过采用对流层经验模型改正对流层干延迟,将基准站和塔顶观测站对流层湿延迟组成相对对流层湿延迟,并联合位置参数和模糊度参数建立双差卡尔曼模型,最后利用最小二乘模糊度降低相关平差法(LAMBDA)对双差模糊度进行固定,并估计位置参数与相对对流层延迟参数。实验结果表明,该方法可以有效估计相对对流层延迟,有效提高GNSS模糊度固定率。 相似文献