共查询到19条相似文献，搜索用时 375 毫秒
1.
随着GPS和GLONASS系统的现代化以及Galileo和BeiDou卫星导航系统的建设,GNSS正朝多频多系统的方向发展。本文对BeiDou B2/Galileo E5b短基线紧组合相对定位的模型与算法进行了研究,详细推导了BeiDou B2/Galileo E5b短基线紧组合相对定位的模型与算法,并对其定位性能进行了分析。重点分析了BeiDou B2与Galileo E5b频点的接收机间差分系统间偏差的长期稳定性,结果表明:基线两端的接收机类型(包括固件版本)相同时,差分系统间偏差接近于0;基线两端的接收机类型不同时,差分系统间偏差较大,但具有长期稳定性,因此能够事先标定并作为改正数用于后续的定位中。最后基于BeiDou B2/Galileo E5b单频单历元相对定位试验对系统间紧组合模型的定位效果进行了比较验证。结果表明,相对于传统的松组合模型,使用改正系统间偏差的紧组合模型能够显著提高模糊度固定的成功率,尤其是在遮挡比较严重、单系统可观测到的卫星数较少的情况下,模糊度固定成功率可以提高10%~25%。 相似文献
2.
针对精密单点定位(Precise Point Positioning,PPP)动态定位精度低、收敛速度慢等问题,本文采用PPP/INS紧组合系统来达到改善PPP动态定位性能的目的。本文对PPP/INS紧组合的观测方程、误差补偿模型、参数估计模型等进行详细推导。通过车载实验采集的卫星观测数据和不同等级的惯性数据,对动态PPP及PPP/INS紧组合的定位定姿性能进行分析,评估不同等级惯性传感器对PPP/INS紧组合定位精度和收敛速度的影响。实验结果表明:PPP/INS紧组合在北—东—高方向的位置RMS相对于PPP分别改善了70.2%、29.1%和16.8%,达到4.8 cm、12.3 cm和7.4 cm。在卫星跟踪条件良好时,惯性传感器性能对PPP/INS紧组合定位精度影响不大;而在卫星观测条件不足时,惯性传感器性能对PPP/INS紧组合定位精度影响明显。此外,仿真和恶劣条件下的数据结果表明,PPP/INS初始定位精度与收敛速度随惯性传感器性能提高而改善明显。 相似文献
3.
ISB是多系统PPP数据处理中必须要考虑的一项误差,因此有必要对BDS/GPS短期ISB建模和预报进行研究。为了提高ISB预报精度,针对等权LS(least square)估计ISB模型参数时忽略了拟合数据权重不同的问题,提出了采用Kalman滤波对模型参数进行估计,并根据ISB拟合数据距预报时刻的远近调整Kalman滤波拟合数据的方差。本文采用7d的ISB数据进行建模,根据所建模型预报第8天的ISB值,并对预报精度和定位结果进行了验证。进行试验的4个测站Kalman拟合模型的ISB预报精度比LS拟合模型分别提高了29.7%、11.5%、43.5%和32.0%。采用Kalman拟合模型的ISB预报值作为先验约束,PPP平均定位精度在E和U方向上比采用LS拟合模型预报值分别多提高了2.7%和0.9%,比不加ISB先验约束在E、N、U方向分别提高了10.6%、26.3%和3.4%。 相似文献
4.
为解决不同GNSS间信号差异引起的多GNSS RTK/INS紧组合导航应用中卫星系统间模糊度固定失败的问题,本文提出顾及ISB/IFB的多GNSS RTK/INS紧组合导航方法,以进一步发挥多GNSS在复杂环境下的互补性和灵活性。本文推导了顾及ISB/IFB的多GNSS RTK/INS紧组合导航观测方程,给出了综合利用抗差估计方法和粒子群优化的ISB/IFB参数估计方法。试验结果表明,顾及ISB/IFB参数可以在一定程度上提高卫星系统间模糊度固定成功率;结合抗差估计方法提高卡尔曼状态估计浮点解精度,可显著提高多GNSS RTK/INS紧组合导航系统在复杂环境下的系统间模糊度固定成功率与导航精度。 相似文献
5.
为评估北斗三号卫星(BDS-3)信号质量及定位性能,针对BDS-3各频点,使用码减相位和双差相位两种组合观测值分析伪距和相位观测精度;评估了BDS-3和GPS同频观测值之间的系统间偏差;分析了BDS-3/GPS松紧组合单频RTK的定位性能。结果表明,同频条件下,BDS-3伪距观测噪声比GPS更低,相位观测噪声在同一水平;在同类型接收机间,BDS-3/GPS的ISB服从均值为0的正态分布;在RTK定位性能上,单系统仅可实现51～57%的模糊度固定率,多系统可实现90%以上的固定率,改正ISB后的紧组合RTK比松组合RTK在固定率和定位精度上有3.4%和3.2%的提升。总体而言,BDS-3信号质量较好,可与GPS兼容互操作,能够进一步提升GNSS的定位性能。 相似文献
6.
《武汉大学学报(信息科学版)》2020,(1)
北斗全球卫星导航系统(简称北斗三号系统,BDS-3)的试验星播发了与GPS L1/L5、欧洲的伽利略(Galileo)系统E1/E5a/E5b频率重叠的新体制信号B1C/B2a/B2b,这为GPS/Galileo/BDS-3试验星重叠频率的紧组合相对定位提供了条件。首先评估了GPS/Galileo/BDS-3试验星重叠频率差分系统间偏差(differential inter-system bias,DISB)的大小与时域稳定性,结果表明,相同类型接收机的DISB接近于0,在紧组合相对定位中可以忽略其影响。然后初步评估了GPS/Galileo/BDS-3试验星短基线单历元紧组合相对定位性能,结果表明,相较于传统的松组合模型,紧组合模型能够显著提高模糊度固定的成功率与可靠性。尤其是在单系统可观测卫星数较少、仅单频观测值可用的情形下,模糊度固定成功率可提高约25%～45%。 相似文献
7.
提出了一种北斗卫星导航系统BDS长距离相对定位方法。在该方法的观测量随机模型中,考虑了BDS的GEO卫星伪距观测量中的系统性多路径变化趋势项的影响;并采用基于非组合观测值的DSOP(Double Station Observation Processing)方法进行数据解算。分别对BDS单系统和BDS/GPS组合相对定位解算结果进行了分析,实验结果都表明采用该方法能够显著提高定位结果的收敛速度。 相似文献
8.
多模全球导航卫星系统（Global Navigation Satellite System,GNSS）精密单点定位（precise point positioning,PPP）存在系统间偏差（inter-system bias,ISB）,构建了顾及系统间偏差的多模GNSS融合PPP算法,对多星座实验（the multi-GNSS experiment,MGEX）监测网中的7个测站观测数据进行静态解算,获得Galileo、GLONASS、北斗与全球定位系统之间的ISB值。分析结果表明,四系统PPP融合定位在水平分量和高程分量的精度分别为8.9 mm、5.3 mm和10.9 mm,体现出较高的融合定位精度。不同系统ISB值在单天内的稳定性较好,均优于0.12 ns。从多天ISB序列看,ISB存在不规律跳变,变化幅度可达近20 ns。不同类型接收机ISB存在一定差异,同一类型接收机结果相近。综合来看,Galileo ISB值最稳定且结果最优,北斗与GLONASS结果相当。 相似文献
9.
在捷联惯导(SINS)和GPS卫星接收机进行紧耦合的研究中,采用差分定位进行紧耦合的方法比较成熟,而关于精密单点定位(PPP)与捷联惯导紧耦合的研究还比较少。本文对精密单点定位与捷联惯导紧组合系统进行了Matlab仿真,利用数学解析的方法产生机载运动轨迹,通过设置系统的参数,获得仿真SINS和GPS数据;然后,通过PPP/SINS紧组合系统的仿真程序解算,将定位结果与PPP的结果比较,表明PPP/SINS紧组合导航定位的结果比PPP的精度和可靠性好,而且收敛的速度更快,同时也验证了算法的正确性。最后,分析了不同等级惯导对定位精度的影响。 相似文献
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11.
北斗三号卫星导航系统（BeiDou-3 navigation satellite system, BDS-3）已全面建成并向全球用户提供可靠的定位、导航和授时（positioning, navigation and timing, PNT）服务。为了实现与其他全球卫星导航系统（global navigation satellite system, GNSS）的兼容性和互操作性,BDS-3在BDS-2的基础上调制了B1C和B2a两个新信号,与伽利略系统（Galileo）的E1和E5a实现了频率的复用。系统间偏差（inter-system bias, ISB）对于实现不同GNSS之间的融合处理至关重要,为此提出了基于单差模型的ISB估计与应用算法,并对BDS-3与Galileo重叠频率之间的ISB进行了分析。基于可跟踪BDS-3新信号的几类接收机,揭示了BDS-3和Galileo之间的ISB的特性,在此基础上分析了BDS-3和Galileo组合的实时动态（real-time kinematic, RTK）定位性能。结果表明,基于相同类型的接收机B1C-E1和B2a-E5a之间是不存在ISB... 相似文献
12.
Teng Liu Yunbin Yuan Baocheng Zhang Ningbo Wang Bingfeng Tan Yongchang Chen 《Journal of Geodesy》2017,91(3):253-268
A joint-processing model for multi-GNSS (GPS, GLONASS, BDS and GALILEO) precise point positioning (PPP) is proposed, in which raw code and phase observations are used. In the proposed model, inter-system biases (ISBs) and GLONASS code inter-frequency biases (IFBs) are carefully considered, among which GLONASS code IFBs are modeled as a linear function of frequency numbers. To get the full rank function model, the unknowns are re-parameterized and the estimable slant ionospheric delays and ISBs/IFBs are derived and estimated simultaneously. One month of data in April, 2015 from 32 stations of the International GNSS Service (IGS) Multi-GNSS Experiment (MGEX) tracking network have been used to validate the proposed model. Preliminary results show that RMS values of the positioning errors (with respect to external double-difference solutions) for static/kinematic solutions (four systems) are 6.2 mm/2.1 cm (north), 6.0 mm/2.2 cm (east) and 9.3 mm/4.9 cm (up). One-day stabilities of the estimated ISBs described by STD values are 0.36 and 0.38 ns, for GLONASS and BDS, respectively. Significant ISB jumps are identified between adjacent days for all stations, which are caused by the different satellite clock datums in different days and for different systems. Unlike ISBs, the estimated GLONASS code IFBs are quite stable for all stations, with an average STD of 0.04 ns over a month. Single-difference experiment of short baseline shows that PPP ionospheric delays are more precise than traditional leveling ionospheric delays. 相似文献
13.
Characterization of between-receiver GPS-Galileo inter-system biases and their effect on mixed ambiguity resolution 总被引：12，自引：6，他引：6
The Global Positioning System (GPS) and Galileo will transmit signals on similar frequencies, that is, the L1–E1 and L5–E5a frequencies. This will be beneficial for mixed GPS and Galileo applications in which the integer carrier phase ambiguities need to be resolved, in order to estimate the positioning unknowns with centimeter accuracy or better. In this contribution, we derive the mixed GPS + Galileo model that is based on “inter-system” double differencing, that is, differencing the Galileo phase and code observations relative to those corresponding to the reference or pivot satellite of GPS. As a consequence of this, additional between-receiver inter-system bias (ISB) parameters need to be solved as well for both phase and code data. We investigate the size and variability of these between-receiver ISBs, estimated from L1 and L5 observations of GPS, as well as E1 and E5a observations of the two experimental Galileo In-Orbit Validation Element (GIOVE) satellites. The data were collected using high-grade multi-GNSS receivers of different manufacturers for several zero- and short-baseline setups in Australia and the USA. From this analysis, it follows that differential ISBs are only significant for receivers of different types and manufacturers; for baselines formed by identical receiver types, no differential ISBs have shown up; thus, implying that the GPS and GIOVE data are then fully interoperable. Fortunately, in case of different receiver types, our analysis also indicates that the phase and code ISBs may be calibrated, since their estimates, based on several datasets separated in time, are shown to be very stable. When the single-frequency (E1) GIOVE phase and code data of different receiver types are a priori corrected for the differential ISBs, the short-baseline instantaneous ambiguity success rate increases significantly and becomes comparable to the success rate of mixed GPS + GIOVE ambiguity resolution based on identical receiver types. 相似文献
14.
多全球导航卫星系统（Global Navigation Satellite System,GNSS）系统联合精密定轨需要考虑系统间及频率间偏差的影响。推导了多GNSS定轨系统间偏差（inter system bias,ISB）/频率间偏差（inter frequency bias,IFB）解算模型,以GPS系统硬件延迟为基准,给出了一种消除ISB/IFB秩亏的约束方法。试验数据结果表明,各系统ISB/IFB均表现出良好的稳定性及同一系统各卫星时间序列的一致性,BDS ISB的标准差为0.36 ns,Galileo ISB的标准差为0.18 ns,GLONASS IFB的标准差为0.51 ns;在接收机类型相同的情况下,不同跟踪站的ISB比较接近,但仍可达到ns级差异;GLONASS IFB在同一跟踪站相同频道号的卫星及不同跟踪站相同频道号卫星均表现出了良好的一致性。 相似文献
15.
Particle filter-based estimation of inter-system phase bias for real-time integer ambiguity resolution 总被引：2，自引：2，他引：0
Although double-differenced (DD) observations between satellites from different systems can be used in multi-GNSS relative positioning, the inter-system DD ambiguities cannot be fixed to integer because of the existence of the inter-system bias (ISB). Obviously, they can also be fixed as integer along with intra-system DD ambiguities if the associated ISBs are well known. It is critical to fix such inter-system DD ambiguities especially when only a few satellites of each system are observed. In most of the existing approaches, the ISB is derived from the fractional part of the inter-system ambiguities after the intra-system DD ambiguities are successfully fixed. In this case, it usually needs observations over long times depending on the number of observed satellites from each system. We present a new method by means of particle filter to estimate ISBs in real time without any a priori information based on the fact that the accuracy of a given ISB value can be qualified by the related fixing RATIO. In this particle filter-based method, the ISB parameter is represented by a set of samples, i.e., particles, and the weight of each sample is determined by the designed likelihood function related to the corresponding RATIO, so that the true bias value can be estimated successfully. Experimental validations with the IGS multi-GNSS experiment data show that this method can be carried out epoch by epoch to provide precise ISB in real time. Although there are only one, two, or at most three Galileo satellites observed, the successfully fixing rate increases from 75.5% for GPS only to 81.2%. In the experiment with five GPS satellites and one Galileo satellites, the first successfully fixing time is reduced to half of that without fixing the inter-system DD ambiguities. 相似文献
16.
Dennis Odijk Nandakumaran Nadarajah Safoora Zaminpardaz Peter J. G. Teunissen 《GPS Solutions》2017,21(2):439-450
Knowledge of inter-system biases (ISBs) is essential to combine observations of multiple global and regional navigation satellite systems (GNSS/RNSS) in an optimal way. Earlier studies based on GPS, Galileo, BDS and QZSS have demonstrated that the performance of multi-GNSS real-time kinematic positioning is improved when the differential ISBs (DISBs) corresponding to signals of different constellations but transmitted at identical frequencies can be calibrated, such that only one common pivot satellite is sufficient for inter-system ambiguity resolution at that particular frequency. Recently, many new GNSS satellites have been launched. At the beginning of 2016, there were 12 Galileo IOV/FOC satellites and 12 GPS Block IIF satellites in orbit, while the Indian Regional Navigation Satellite System (IRNSS) had five satellites launched of which four are operational. More launches are scheduled for the coming years. As a continuation of the earlier studies, we analyze the magnitude and stability of the DISBs corresponding to these new satellites. For IRNSS this article presents for the first time DISBs with respect to the L5/E5a signals of GPS, Galileo and QZSS for a mixed-receiver baseline. It is furthermore demonstrated that single-frequency (L5/E5a) ambiguity resolution is tremendously improved when the multi-GNSS observations are all differenced with respect to a common pivot satellite, compared to classical differencing for which a pivot satellite is selected for each constellation. 相似文献
17.
Navigation applications will benefit significantly from the improved reliability, availability, and accuracy offered by combining BeiDou Navigation Satellite System (BDS) and Global Positioning System (GPS). In the BDS/GPS navigation data fusion model, the effect of inter-system bias (ISB) must be considered. We present a detailed analysis of the pseudorange measurements for BDS and GPS and demonstrate the existence of code ISB in BDS/GPS measurements. The ISB mainly consists of the time system offset, the coordinate system difference, and the inter-system hardware delay bias. A method based on statistical hypothesis testing is proposed to assess the stability and difference of the BDS–GPS ISB. Real data from 18 stations equipped with six types of receivers are used to compute the ISB. The results illustrate that (a) receiver-dependent ISBs are evident and comparatively consistent, with the maximum ISB observed in our experiments being ?1516 ns, (b) these receiver-dependent ISBs exhibit great stability in terms of their standard deviation and intra-day variation, and (c) the estimated ISBs for each BDS satellite type with respect to GPS are consistent. 相似文献
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19.
The integration of GPS with GLONASS may be considered a major milestone in satellite-based positioning, because it can dramatically
improve the reliability and productivity of said positioning. However, unlike GPS, GLONASS satellites transmit signals at
different frequencies, which result in significant complexity in terms of modeling and ambiguity resolution for integrated
GPS and GLONASS positioning systems. In this paper, a variety of mathematical and stochastic modeling methodologies and ambiguity
resolution strategies are analyzed, and some remaining research challenges are identified. The exercise, of developing mathematical
models and processing methodologies for integrated systems based on more than one satellite system, is a valuable one as it
identified crucial issues concerned with the combination of any two or more microwave positioning systems, be they satellite-based
or terrestrial. Hence these are experiences that can be applied to future projects that might integrate GPS with Galileo,
or GLONASS and Galileo, or all three. ? 2001 John Wiley & Sons, Inc. 相似文献