共查询到18条相似文献，搜索用时 156 毫秒
1.
为了系统验证SINS／GPS紧组合系统的性能,基于GPS软件接收机,进行了仿真系统构建。仿真系统由轨迹发生器、GPS中频信号模拟器、IMU信号模拟器、GPS软件接收机、SINS导航解算模块、组合滤波算法和导航性能分析模块等部分构成,其中详细设计了GPS软件接收机中的捕获和跟踪算法、SINS解算以及基于伪距和伪距率的组合滤波算法。仿真结果表明：紧组合导航系统收敛性较好,能够一定程度上抑制惯导系统误差的积累,有较好的导航性能。设计的该系统满足紧组合导航系统性能验证的需要,也为后续的超紧组合研究奠定了良好的基础。 相似文献
2.
在常规单像空间后方交会的解算过程中,整体最小二乘(TLS)算法在减小地面控制点及观测变量存在的误差方面有较广泛的应用。但在解算不等精度测量时,直接采用TLS算法进行参数估计易出现解失真的情况,因此为提高解算精度,可以为不同观测值定权,进行外方位元素的计算。本文以解算全微分共线方程为研究主线,并引进协因数阵为观测值定权,尝试采用加权整体最小二乘算法(WTLS)对单像空间后方交会进行解算。实验结果表明,本文算法较最小二乘算法与整体最小二乘算法在精度和准确度方面均有较大提高,在单像空间后方交会解算中具有较好的应用前景。 相似文献
3.
针对微弱信号下GPS接收机无法测量得到完整信号发射时刻的问题,提出了一种基于模糊度搜索的辅助式GPS定位算法。基于该算法接收机不需要位同步、帧同步和解调导航电文,仅对GPS信号进行伪码相位测量,在获取卫星星历、卫星钟差参数等辅助信息的基础上完成定位解算。论文从数学上严格推导了消除信号发射时刻模糊度的条件,并对五颗以上的观测卫星建立了定位解算方程,给出了算法流程。利用实测数据仿真验证了该算法的有效性。比较表明,该算法的定位精度与常规GPS定位算法(信号发射时刻不存在模糊度)相当。 相似文献
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5.
传统的基于硬件的接收机由于芯片的封装性很难用来进行通道信号的分析研究,而基于软件无线电技术的软件接收机则很容易做到。软件接收机的跟踪通道信号统计分析可用于接收机算法的测试与比对以及卫星信号性能的分析与评估。这里搭建了GPS软件接收机L1中频数字信号处理平台,对跟踪通道输出的I、Q支路信号进行了均值、标准方差以及均方根(RMS)统计。分析了各统计值与通道对应卫星的高度角、信号强度以及噪声之间的关系。基于统计结果提出了一种估计信道信噪比的方法。最后比较了不同信号采样频率对相关三角形和导航定位解算精度的影响。 相似文献
6.
针对目前常用的超宽带算法,扩展卡尔曼滤波(EKF)在解算过程中产生的线性化误差,对定位结果产生影响,而无损卡尔曼滤波(UKF)算法可以不进行线性化过程进行解算,避免误差的产生。文中首先对UWB定位系统线性化误差进行分析,在此基础上提出UKF和TDOA相结合的定位模型,通过实验比较两种算法的定位精度。实验结果表明UKF算法定位结果相比于EKF算法在U方向上有明显提升,误差稳定在10 cm之内。同时,通过改变初始坐标偏差,来进一步比较两种算法的定位效果,结果表明,初始偏差设置为0.5 m时,UKF算法比EKF算法U方向精度提升15%;初始偏差设置为1 m时,UKF算法U方向精度提升60%以上;初始偏差设置为5 m和10 m时,UKF算法U方向精度提升可以达到90%。EKF算法会产生不可忽略的线性化误差且误差会随着初始偏差增大而增大,UKF算法则可以保持较好的定位精度和稳定性。 相似文献
7.
传统的基于硬件的接收机由于芯片的封装性很难用来进行通道信号的分析研究,而基于软件无线电技术的软件接收机则很容易做到.软件接收机的跟踪通道信号统计分析可用于接收机算法的测试与比对以及卫星信号性能的分析与评估.这里搭建了GPS软件接收机L1中频数字信号处理平台,对跟踪通道输出的I、Q支路信号进行了均值、标准方差以及均方根(RMS)统计.分析了各统计值与通道对应卫星的高度角、信号强度以及噪声之间的关系.基于统计结果提出了一种估计信道信噪比的方法.最后比较了不同信号采样频率对相关三角形和导航定位解算精度的影响. 相似文献
8.
龚涛 《测绘科学技术学报》2000,17(2):86-90
如何在线精确地求解整周模糊度,是GPS高精度动态相对定位的关键问题.在线解算取决于很多因素:基线长度、数据处理方法、接收机的性能(如双频还是单频)以及抗AS和SA的能力等.现代双频GPS接收机能获得载波相位和L1、L2频道上的精密伪距观测值,组合这4个观测值可进行单历元整周模糊度解算.文中对组合码和相位观测值在线解整周模糊度的算法进行了试验和分析,得出了很有实用意义的结论. 相似文献
9.
高性能稳健性的GPS卫星接收机仍然是当前研究和发展的热点。在高动态条件下,GNSS接收机设计总是涉及到跟踪动态性能所要求的环路带宽和噪声所要求的环路带宽一对矛盾体。以微惯性测量单元(MIMU)辅助的GPS接收机为实例,设计了MIMU辅助的GPS接收机搜索算法和跟踪算法,同时为减少GPS接收机对惯性器件的性能的依赖,设计了基于MIMU辅助的最优GPS接收机的环路带宽。通过仿真和车载试验对所设计的方法进行验证,仿真和试验结果表明,MIMU辅助的GPS接收机动态性能取决于MIMU的性能指标和环路的带宽,而抗干扰性能至少有13 dB的提高;跑车试验中,商用GPS接收机和研制的GPS接收机精度大体相当。同时系统还能够提供姿态角信息。 相似文献
10.
观测数据中常包含统计信息未知的不确定性,可能导致所建立的函数模型产生病态,影响参数估计的准确性和可靠性。文中研究GPS高程拟合模型的不确定性,将系数矩阵进行分块,对含有不确定性的区块加以限制,并将不确定度融入函数模型,利用min-max准则,运用带部分不确定性的平差算法(PULS,Least-Squares with Part of Uncertainty)解算拟合参数。实验中选取均匀分布的模拟点坐标及其高程异常值,分别运用最小二乘(LeastSquares,LS)、总体最小二乘(Total Least-Squares,TLS)以及PULS对拟合参数进行解算,结果表明,PULS得到的拟合参数精度高于LS和TLS,说明PULS在GPS高程拟合中应用的有效性。 相似文献
11.
Much of the research into multipath detection and mitigation has not considered the carrier phase delay between the line of
sight (LOS) and reflected signals. A new variable referred to as early late phase (ELP) has recently been proposed to exploit
this phase difference. It has been found that in a receiver tracking the L1 GPS signal, the probability of detecting multipath
is lower when the carrier phase difference between the LOS and a reflected signal is an integer multiple of π. Since the pseudorange
error caused by the multipath’s presence is the highest in this case, we propose to exploit the coexistence of another GPS
civilian signal, the L2C. We present an analysis of ELP for the L1 and L2C signals, and a combination of both, for detecting
multipath. The multipath detection performance has been compared using probabilities of false alarm and detection. An ideal
algorithm should have lower probability of false alarm and higher probability of detection. However, it has been found that
using dual-frequency ELP increases both probabilities. Thus, receiver operator characteristics (ROC) curves, and the area
under the ROC curves, have been used for effective comparison. It has been found that the L2C signal individually gives worse
performance than L1 because of its weaker signal strength. However, the combination of L1 and L2C gives the best overall performance,
and thus it can be claimed that ELP using dual-frequency receivers is a more effective approach for detecting multipath. 相似文献
12.
In this article, the architecture of a software Global Positioning System (GPS) receiver is described and an analysis is included
of the performance of a software GPS receiver when tracking the GPS signals in challenging environments. Results are included
that demonstrate the advantage of the software GPS receiver in tracking the GPS signals in low signal-to-noise or jamming
scenarios. Various current and previous applications of the software GPS receiver are also described. ? 2000 John Wiley &
Sons, Inc. 相似文献
13.
GPS共视接收机短期观测资料处理算法研究 总被引：1，自引：0，他引：1
提出了一种新的基于总体最小二乘数据拟合的短期观测资料处理算法 ,同时考虑测量时刻和时差测量值的不确定性 ,可提高共视接收机输出的单站数据精度。超短基线单通道共视测量数据表明 ,使用新算法后 ,可以提高原始共视数据短期稳定度 相似文献
14.
GPS Solutions - The equivalent bandwidth of a Kalman filter (KF) tracking loop for a Global Navigation Satellite System receiver is widely used to compare the performance of the KF with that of the... 相似文献
15.
Dong-Hwan Hwang Sang Heon Oh Sang Jeong Lee Chansik Park Chris Rizos 《GPS Solutions》2005,9(4):294-311
Due to their complementary features of GPS and INS, the GPS/INS integrated navigation system is increasingly being used for
a variety of commercial and military applications. An attitude determination GPS (ADGPS) receiver, with multiple antennas,
can be more effectively integrated with a low-cost IMU since the receiver gives not only position and velocity data but also
attitude data. This paper proposes a low-cost attitude determination GPS/INS integrated navigation system. The proposed navigation
system comprises an ADGPS receiver, a navigation computer unit (NCU), and a low-cost commercial MEMS IMU. The navigation software
includes a fault detection and isolation (FDI) algorithm for integrity. In order to evaluate the performance of the proposed
navigation system, two flight tests have been performed using a small aircraft. The first flight test confirmed the fundamental
operation of the proposed navigation system and the effectiveness of the FDI algorithm. The second flight test evaluated the
performance of the proposed navigation system and demonstrated the benefit of GPS attitude information in a high dynamic environment.
The flight test results show that the proposed ADGPS/INS integrated navigation unit gives reliable navigation performance
even when anomalous GPS data is provided and gives better navigation performance than a conventional GPS/INS unit. 相似文献
16.
This paper preliminarily investigates the application of unscented Kalman filter (UKF) approach with nonlinear dynamic process
modeling for Global positioning system (GPS) navigation processing. Many estimation problems, including the GPS navigation,
are actually nonlinear. Although it has been common that additional fictitious process noise can be added to the system model,
however, the more suitable cure for non convergence caused by unmodeled states is to correct the model. For the nonlinear
estimation problem, alternatives for the classical model-based extended Kalman filter (EKF) can be employed. The UKF is a
nonlinear distribution approximation method, which uses a finite number of sigma points to propagate the probability of state
distribution through the nonlinear dynamics of system. The UKF exhibits superior performance when compared with EKF since
the series approximations in the EKF algorithm can lead to poor representations of the nonlinear functions and probability
distributions of interest. GPS navigation processing using the proposed approach will be conducted to validate the effectiveness
of the proposed strategy. The performance of the UKF with nonlinear dynamic process model will be assessed and compared to
those of conventional EKF. 相似文献
17.
为了满足高动态用户及强干扰条件下的应用需求,提出了一种基于卫星信号矢量跟踪的SINS/GPS深组合导航方法,设计了基于FPGA硬件平台的实施方案。利用组合卡尔曼滤波器反馈回路取代了传统接收机中独立、并行的跟踪环路,能够同时完成所有可视卫星信号的跟踪和导航信息处理;通过矢量跟踪算法对所有可视卫星信号进行集中处理,能够增强跟踪通道对信号载噪比变化的适应能力,从而提高接收机在强干扰或信号中断条件下的跟踪性能;根据SINS导航参数和星历信息推测GPS伪码相位和多普勒频移等参数,用以辅助卫星信号的捕获和跟踪,能够大大缩短接收机的搜索捕获时间,并增强接收机在高动态条件下的跟踪性能。基于矢量跟踪的深组合方法不仅在GPS信号短暂中断期间,能够保证系统的导航精度和可靠性,而且在强干扰环境中能够维持较好的伪码相位和载波频率跟踪性能。 相似文献