共查询到19条相似文献,搜索用时 93 毫秒
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论文介绍了GPS/GLONASS组合静态相位相对定位模型,将GLONASS双差观测方程的模糊度参数表示成参考卫星的单差模糊度和双差模糊度参数;用误差分析法证明了单差模糊度按实参数估计不影响基线解算精度,而GLONASS双差模糊度必须按整参数进行解算;用Helmert方差分量估计确定GPS和GLONASS观测值的合理权比。实际观测数据处理结果表明:GPS/GLONASS组合定位较单一系统解算的基线精度均有提高,尤其比GLONASS单系统的解算精度有显著提高,比GPS单系统的精度也有适当提高,其中单历元基线解算精度约提高了10%,当单一系统的可用卫星数少于4颗时,GPS/GLONASS组合定位更具有应用价值。 相似文献
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进行独立参数化时,GNSS观测方程的双差、单差与非差观测方程理论上是等价的。利用按高度角定权的模型以及不同测站跟踪不同数量卫星的等价观测方程,实现基于简化等价观测方程的GPS/GLONASS组合多基线解算,包括多基线模糊度的固定、基线向量的解算与精度分析,并用多个测站的GPS/GLONASS同步实测载波相位和码伪距观测数据完成多基线解算分析。计算结果表明,由于多个测站的同时作用导致几何强度增强,降低模糊度间的相关性,有利于模糊度的快速解算;同时简化等价观测方程,提高法方程的形成速度,解算的基线精度也优于单基线解算模式。 相似文献
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采用频分多址技术(FDMA),GLONASS系统双差模糊度固定存在两个问题:不同卫星波长不一致,双差后不能保持模糊度整数特性;共视卫星频率不同,不同卫星之间存在大小不同的频间偏差(IFB)。传统的双差不能很好处理GLONASS相对定位模糊度固定问题。文中考虑将双差所涉及的两颗卫星的站间单差模糊度分别求解,不受共视卫星波长不一致的影响。同时采用参数估计法消除不同厂商接收机的频间偏差影响。试验结果表明采用文中方法可以正确固定GLONASS模糊度,并且达到与GPS相当的解算精度,GPS/GLONASS组合定位精度和可靠性也比GPS单系统有所提高。 相似文献
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针对常规GNSS解算模糊度存在的问题,该文提出了一种新的GNSS宽巷模糊度单历元求解算法。利用单历元双频码伪距观测值和载波相位观测值得到双差宽巷模糊度浮点解,将所有浮点宽巷模糊度分别向上、向下取整建立模糊度搜索空间;将模糊度空间中的所有备选组合代入双差宽巷观测方程中进行最小二乘解算,其中单位权中误差最小的组合就是最优的宽巷模糊度组合;然后对最优组合进行正确性检验以确定宽巷模糊度。确定宽巷模糊度后,可以利用宽巷观测值和载波观测值求出基础模糊度整周解。实验表明,该文提出的模糊度固定方法具有较高的成功率和可靠性,静态数据中模糊度固定成功率达到98.84%,动态数据中模糊度固定成功率达到了99.60%。 相似文献
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北斗卫星导航系统双差网络RTK方法 总被引:1,自引:1,他引:0
针对北斗卫星导航系统常规实时动态差分(RTK)定位中,整周模糊度的快速解算和流动站位置信息的解算精度问题,该文研究了一种北斗卫星导航系统双频双差网络RTK方法,首先解算参考站网B1、B2载波相位整周模糊度,利用固定的参考站网载波相位整周模糊度计算参考站的观测误差,使用区域误差内插法计算流动站的综合误差影响,改正流动站的观测误差并进行流动站的整周模糊度解算,最后使用实测数据进行算法实验。实验结果表明,该文的方法可以利用北斗卫星导航系统双频观测数据实现网络RTK流动站的厘米级定位。 相似文献
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大范围网络RTK基准站间整周模糊度实时快速解算 总被引:1,自引:0,他引:1
网络RTK是目前实现高精度实时动态定位的重要手段之一,而网络RTK高精度定位的关键问题是基准站间整周模糊度的实时快速准确固定。对于大范围网络RTK,由于基准站间距离的增加,电离层延迟误差、对流层延迟误差和卫星轨道误差相关性降低,导致基准站间整周模糊度不能快速准确地固定,因此本文提出了一种大范围网络RTK基准站间整周模糊度固定算法。该算法首先利用L1、L2载波相位观测值和P1、P2伪距观测值解算基准站间的双差宽巷模糊度;然后采用Saastamoinen模型和Chao映射函数模型相结合解算双差对流层延迟误差,并将双差宽巷模糊度作为L1、L2双差载波相位整周模糊度的约束关系来确定L1、L2双差载波相位整周模糊度;最后采用CORS站的实测数据进行试验,并将本文的试验结果同GAMIT软件的解算结果进行比对,结果表明该算法可以快速准确地实现单历元双差载波相位整周模糊度的固定。 相似文献
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为解决DUFCOM方法单历元解算GPS双差整周模糊度因观测卫星数多导致解算效率低而影响GPS高频数据实时动态解算这一问题,同时考虑到DC算法解算效率高的优点,对观测卫星进行筛选分级处理,提出了一种快速确定算法。算例表明,该算法可避免在应用DUFCOM方法中二级卫星对一级卫星双差整周模糊度解算效率的影响,使得GPS单历元确定双差整周模糊度的效率显著提高,达到了GPS高频数据实时动态解算的目的。 相似文献
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虚拟参考站(VRS)技术是目前GPS网络RTK系统研究领域的热点之一,而参考站间整周模糊度的在线解算则是VRS/RTK的关键技术。本文针对中长基线的整周模糊度解算,采用两步法求解:一是提出了采用消电离层伪距组合和双频相位组合法求解宽巷模糊度,该方法既不需要高精度的P码,也不需要顾及电离层的影响;二是对于解算L1双差模糊度,探讨了采用序贯最小二乘法解算模糊度,提出一种改进的序贯最小二乘方法,本方法既能削弱模糊度解算过程中法方程的病态性,又不影响模糊度固定时间,并结合算例进行了分析。 相似文献
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Influence of ambiguity precision on the success rate of GNSS integer ambiguity bootstrapping 总被引:1,自引:0,他引:1
P. J. G. Teunissen 《Journal of Geodesy》2007,81(5):351-358
In this contribution, we study the dependence of the bootstrapped success rate on the precision of the GNSS carrier phase
ambiguities. Integer bootstrapping is, because of its ease of computation, a popular method for resolving the integer ambiguities.
The method is however known to be suboptimal, because it only takes part of the information from the ambiguity variance matrix
into account. This raises the question in what way the bootstrapped success rate is sensitive to changes in precision of the
ambiguities. We consider two different cases. (1) The effect of improving the ambiguity precision, and (2) the effect of using
an approximate ambiguity variance matrix. As a by-product, we also prove that integer bootstrapping is optimal within the
restricted class of sequential integer estimators. 相似文献
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Andrew Sowter 《The Photogrammetric Record》2003,18(104):308-324
Interferometric SAR (InSAR) has established itself as a useful technique for precise cloud-independent topographic surveying and for the monitoring of topographic change at sub-centimetric accuracies. Despite this, measurements of the phase are still only available modulo 2 π and this leads to an ambiguity problem that is usually not explicitly resolved.
This paper presents a generalised method for the precise determination of the phase ambiguity that is independent of datum and projection biases. The method is based on those applied to Global Navigation Satellite Systems (GNSS) signals and shows that the far-field approximation is insufficient for precise positioning. Geometric similarities between InSAR and radargrammetry are highlighted. The solution presented allows the geolocation of a target to an accuracy limited only by the accuracy of the transmit–receive time of the sensor. 相似文献
This paper presents a generalised method for the precise determination of the phase ambiguity that is independent of datum and projection biases. The method is based on those applied to Global Navigation Satellite Systems (GNSS) signals and shows that the far-field approximation is insufficient for precise positioning. Geometric similarities between InSAR and radargrammetry are highlighted. The solution presented allows the geolocation of a target to an accuracy limited only by the accuracy of the transmit–receive time of the sensor. 相似文献
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首先指出了基于传统的假设检验理论的三步法在评价模糊度整数解正确性时存在的理论缺陷,然后介绍了模糊度归整域的概念和可容许整数估计的定义,并在可容许整数估计原定义的基础上给出了更为严密的新定义。最后,基于这个可容许整数估计的新定义,讨论了模糊度成功率的概念及其计算公式。从理论上讲,只有模糊度的成功率才是评价模糊度整数解正确性的严密尺度。 相似文献
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A new approach to GPS ambiguity decorrelation 总被引:13,自引:1,他引:12
Ambiguity decorrelation is a useful technique for rapid integer ambiguity fixing. It plays an important role in the least-squares
ambiguity decorrelation adjustment (Lambda) method. An approach to multi-dimension ambiguity decorrelation is proposed by
the introduction of a new concept: united ambiguity decorrelation. It is found that united ambiguity decorrelation can provide
a rapid and effective route to ambiguity decorrelation. An approach to united ambiguity decorrelation, the HL process, is
described in detail. The HL process performs very well in high-dimension ambiguity decorrelation tests.
Received: 9 March 1998 / Accepted: 1 June 1999 相似文献
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In this paper, the capability of the integer ambiguity method to find the absolute position of InSAR data is demonstrated. A radargrammetric model is used for the space triangulation. The method is demonstrated using ERS data of the Thames region and the results are compared to GPS measurements and a digital elevation model. The GPS stations, not visible in the image, are located on the InSAR data using a simple range-Doppler algorithm and an analysis of their positions is undertaken. The results are consistent with other methods but with the advantage that the radargrammetric model is very simple. The results also highlight the problems of integrating GPS data with InSAR data in urban areas where a GPS station may not be representative of the dominant scatterers within a resolution cell, and they suggest methods that might be applied in future to reduce this problem. The model should help the integration of InSAR data with other geometric survey data. 相似文献
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P. J. G. Teunissen 《Journal of Geodesy》1997,71(6):370-383