共查询到19条相似文献,搜索用时 484 毫秒
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电离层延迟误差是单频接收机的主要定位误差之一。电离层延迟误差具有多变性,不易准确描述。本文探讨了几种常用单频接收机电离层延迟改正模型,Bent模型IRI模型、Klobuchar模型、NeQuick模型以及IGGSH模型。并利用单频GPS接收机实测数据统计分析各模型对定位误差的修正效果,为单频接收机用户选择合适的电离层改正模型提供参考。 相似文献
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本文对单频GPS系统中载波相位平滑伪距算法进行研究,改进了传统平滑器,以消弱电离层延迟影响为基础,设计获得影响平滑器的各个因素的方案,用软件实现该平滑器并且进行动态实验验证,证明了该平滑算法的可行性和有效性。 相似文献
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电离层传播延迟是C/A码GPS导航定位的主要误差源之一,本文提出了一种利用C/A码GPS接收机实现电离层延迟实时双频改正的方法,并对实现这一方法的电路框图的原理进行了分析,从理论上说明其可行性。 相似文献
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精密单点定位(Precise Point Positioning, PPP)利用接收机收到的载波相位测量值进行定位,载波相位整周模糊度的固定影响着PPP的收敛速度和定位精度。采用B2a信号替代B2I信号,与B1I、B3I组成三频信号观测值组合,在此基础上对传统Boot-strapping方法加以改进,提出了一种改进的三频模糊度解算方法。该方法采用了超宽巷-超宽巷-宽巷-窄巷的解算策略,通过比较选择波长较长、电离层延迟较小、测量噪声较小的三频观测值组合,分别用于解算超宽巷组合、宽巷组合和窄巷组合的模糊度。当电离层延迟无法忽略时,所提方法通过引入额外的伪距观测量来消除在解算组合模糊度的过程中出现的电离层参数和几何参数的影响。实验表明,所提方法与传统方法在完成一次模糊度解算的时间上相差无几,但是相比于传统方法,所提方法具有更高的模糊度解算成功率。 相似文献
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基于削弱实时动态精密单点定位多路径效应的目的,首先分析了多路径误差的产生原理,利用信噪比与高度角的关系判断多路径产生的来源,利用TEQC软件量化多路径误差的大小.其次分析了一般导航定位中的设置截止高度角法减少多路径效应在实时动态精密单点定位中的作用,试验表明这种方法并不适用于精密单点定位.基于Estimate SETC模型和Iono-Free LC对多路径效应对电离层改正的影响进行了研究,发现当多路径效应显著时,双频电离层改正会带来更大的误差,不利于精密单点定位的高精度解算.最后根据实际数据解算结果,在多路径效应显著的情况下,建议选用精确的模型改正消除电离层误差,而不使用双频消除电离层延迟法. 相似文献
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GPS信号的多普勒效应分析 总被引:1,自引:1,他引:0
给出了GPS信号多普勒效应以及利用多普勒观测量计算电离层总电子含量的计算公式。利用这些公式及GPS接收机的多普勒观测量对运动多普勒和电离层引起的介质多普勒进行了分析,给出了利用多普勒观测量计算的电离层总电子含量。结果表明:GSP的运动多普勒在正负几千赫兹之间,与运动多普勒相比,GPS信号的介质多普勒要小得多,其量级在10^-2赫兹;利用GPS多普勒观测量可计算电离层总电子含量,其相对变化精度要高于利用伪距观测量的计算结果,但低于利用伪距+载波相位观测量的计算结果。 相似文献
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电离层高频反射回波的多普勒频移观测是研究电离层扰动的一个重要方法.利用电离层垂直探测中的组合脉冲控制和回波相位测量分析方法,开发并实现了一种电离层扰动观测模式.实验观测表明,新开发的观测模式在电离层高频反射回波为窄带信号的情况下,可实时获得高精度多普勒频高图,并给出电离层扰动速度的时空变化曲线,能够满足电离层扰动观测研究的需要. 相似文献
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Zhang Mengyang Lu Baowei Song Wenmiao 《电子科学学刊(英文版)》1999,16(1):66-72
The ionospheric time delay is one of the main error sources in C/A code GPS navigation and positioning applications. In this paper, a method is proposed for real-time dual-frequency ionospheric time-delay correcting using a C/A code GPS receiver, and the principle of the circuit block diagram for this method is analyzed with its feasibility theoretically demonstrated. 相似文献
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The need for precise position and navigation aids in many areas of industry is becoming increasingly apparent. There are many errors associated with the navigation solution of the global positioning system (GPS), including satellite ephemeris error, satellite clock error, ionospheric delay, tropospheric delay, multipath, receiver measurement error and selective availability (SA). Noise can create an error between centimeters to several meters. In this paper, the proposed technique applied to smooth noise for GPS receiver positioning data is based upon the analysis of wavelet transform (WT), bilateral filter (BF) and diffusivity function. The WT is a powerful tool of signal processing for its multiresolutional possibilities. BF is a local, non-linear and non-iterative technique. It is applied to approximation subband. We decompose a GPS positioning data into low-frequency and high-frequency components and apply BF on the approximation coefficients and diffusivity function on the detail coefficients at each decomposition level for data smoothing. A single-frequency and low-cost commercial GPS receiver manufactured by Rockwell Company is used to test our method. The experimental results on measurement data demonstrate the effectiveness of the proposed method; so that the total root mean square (RMS) error reduces to less than 0.29 m with SA on and 0.15 m with SA off using Daubechie wavelet. 相似文献
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伴随着北斗卫星导航系统的发展成熟,采用多个卫星导航系统可以获得更多的观测卫星进行电离层闪烁监测,极大提高监测的性能,因此利用GPS系统与北斗系统结合进行电离层闪烁监测成为趋势。文中介绍了所研制的GPS/BD双模电离层闪烁监测系统,它可以实时地监测分析GPS卫星L1/L2频点与北斗卫星B1/B2频点信号的电离层幅度闪烁指数和电离层相位闪烁指数,并可显示和存储各项观测数据。文中对电离层闪烁监测系统的硬件、系统嵌入式软件和电离层闪烁监测上位机软件的设计进行了介绍,对消趋势滤波器的设计和闪烁指数的计算进行了详细的讨论,并在最后给出了系统运行测试结果。 相似文献
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高动态GPS卫星信号模拟器关键技术分析及应用 总被引:19,自引:1,他引:18
介绍了高动态GPS卫星信号模拟器的组成,阐述了模拟器的工作原理,给出了在研模拟器的主要技术指标,分析了模拟器研制涉及到的部分关键技术:高动态信号的产生与精度控制、电离层延迟误差模拟、多径信号模拟和差分数据产生,最后列举了高动态GPS卫星信号模拟器的几种应用。 相似文献
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The global positioning system (GPS), with its ability to provide time synchronization with accuracy to 200 ns over the wide area, provides an ideal tool for performing time tagging in electric power systems. The observed GPS pseudo-range varies from the true range because of range measurement errors. GPS errors sources are ionospheric delays, atmospheric delays, troposphericelays, multi-path effects and dilution of precision etc., affecting the GPS signals as they travel from satellite to user on Earth. In this paper neural models has been presented are for more accurate GPS timing in electric power systems with a single-frequency GPS receiver. The proposed methods use back-propagation (BP), extended Kalman filter (EKF) and particle swarm optimization (PSO) training algorithms, which achieves the optimal training criterion. We use actual data to evaluate the performance of the proposed methods. An experimental test setup is designed and implemented for this purpose. Results using the three methods are discussed. The experimental results obtained from a coarse acquisition (C/A)-code single-frequency GPS receiver are provided to confirm the efficacy of the approaches to give high accurate timing. The GPS timing RMS error using neural network based on PSO learning algorithm reduces to less than 105 and 36 ns, before and after SA, respectively. 相似文献
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With the development of the Ground Positioning System (GPS) modernization and the expectable implementation of Galileo, people pay more and more attention to civil applications on multi-frequency signals. This paper proposes a new and advanced positioning algorithm for the dual-frequency satellite navigation receivers, concerning the various influences of all the ranging error sources and taking advantage of the Klobuchar single-frequency ionospheric model. The paper also presents positioning precision prov... 相似文献