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1.
Removing attitude-related variations in the line-of-sight for kinematic GPS positioning 总被引：1，自引：1，他引：0
Stavros A. Melachroinos Mayaba Tchalla Richard Biancale Yves Menard 《GPS Solutions》2011,15(3):275-285
We are presenting a method for removing attitude-related variations (ATTRVs) in dynamic 1 Hz GPS positioning. The ATTRVs are
separated into vertical and horizontal components. These result from the translational and rotational motions of the vehicle,
which is a marine research vessel in our case. We have developed new observation equations that use corrected pseudoranges
and carrier phases to account for ATTRVs. In the present contribution, we are only focusing on the vertical signals. These
modeled ATTRVs are included as corrections in the line-of-sight (LoS) to each GPS satellite in the RINEX data sets using a
new software called RNXATTCOR. Precise IGS sp3-orbits are used as inputs together with precise lever arm coordinates of the
onboard GPS antennas, observations from the marine inertial navigation system and a priori 3D position of the vessel. The
corrected RINEX data sets are then processed using kinematic processing or sequential processing in Precise Point Positioning
(PPP) mode. The reduction of the standard deviation from a running mean in the final processed GPS time series is about 95%.
The current method is being proposed for marine geodesy science applications such as along-track calibration/validation of
altimetry products, and also for applications related to offshore kinematic high precision GPS positioning such as drilling,
offshore platforms stability, marine pipeline positioning, earthquake monitoring and tsunami detection. 相似文献
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Altti Jokinen Shaojun Feng Wolfgang Schuster Washington Ochieng Chris Hide Terry Moore 《地球空间信息科学学报》2013,16(3):141-148
Traditional positioning methods, such as conventional Real Time Kinematic (cRTK) rely upon local reference networks to enable users to achieve high-accuracy positioning. The need for such relatively dense networks has significant cost implications. Precise Point Positioning (PPP) on the other hand is a positioning method capable of centimeter-level positioning without the need for such local networks, hence providing significant cost benefits especially in remote areas. This paper presents the state-of-the-art PPP method using both GPS and GLONASS measurements to estimate the float position solution before attempting to resolve GPS integer ambiguities. Integrity monitoring is carried out using the Imperial College Carrier-phase Receiver Autonomous Integrity Monitoring method. A new method to detect and exclude GPS base-satellite failures is developed. A base-satellite is a satellite whose measurements are differenced from other satellite’s measurements when using between-satellite-differenced measurements to estimate position. The failure detection and exclusion methods are tested using static GNSS data recorded by International GNSS Service stations both in static and dynamic processing modes. The results show that failure detection can be achieved in all cases tested and failure exclusion can be achieved for static cases. In the kinematic processing cases, failure exclusion is more difficult because the higher noise in the measurement residuals increases the difficulty to distinguish between failures associated with the base-satellite and other satellites. 相似文献
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全球导航卫星系统（GNSS）参考网多用于估计卫星轨道/钟差、监测地表形变和速度场、确定精密地球自转参数等方面。相关数据处理模式包括：双差基线解（DD）和非差精密单点定位（PPP）等。本文首先从GNSS基本观测方程出发,通过选取两组基准参数,导出了上述两模式下的列满秩观测方程,然后分析了它们的不足,例如：相位偏差在DD模式中吸收了钟差,丧失了时不变特性;模糊度在PPP模式中吸收了相位偏差,失去了整数性。基于上述分析,本文提出了一种新的参考网数据处理方案,以充分融合DD和PPP模式的优势。它的关键策略是精选基准参数,以达到消秩亏的目的,具体优点体现在：相位偏差独立可估,若合理约束为时不变参数,可充分减少参数个数,提高网解精度;待估模糊度具备整周特性,经由模糊度固定,可改善网解可靠性。 相似文献
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在精细考虑伪距和载波相位硬件偏差时变特性的基础上,导出了更为严谨的非差非组合观测方程,并给出了非组合模式下两类GNSS偏差的数学表达形式.基于此,本文详细研究了3种常用的三频精密单点定位(PPP),即无电离层两两组合IF1213、单个无电离层组合IF123与非组合UC123函数模型的独立参数化方法,系统分析了3种PPP... 相似文献
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Currently, the GNSS computing modes are of two classes: network-based data processing and user receiver-based processing. A GNSS reference receiver station essentially contributes raw measurement data in either the RINEX file format or as real-time data streams in the RTCM format. Very little computation is carried out by the reference station. The existing network-based processing modes, regardless of whether they are executed in real-time or post-processed modes, are centralised or sequential. This paper describes a distributed GNSS computing framework that incorporates three GNSS modes: reference station-based, user receiver-based and network-based data processing. Raw data streams from each GNSS reference receiver station are processed in a distributed manner, i.e., either at the station itself or at a hosting data server/processor, to generate station-based solutions, or reference receiver-specific parameters. These may include precise receiver clock, zenith tropospheric delay, differential code biases, ambiguity parameters, ionospheric delays, as well as line-of-sight information such as azimuth and elevation angles. Covariance information for estimated parameters may also be optionally provided. In such a mode the nearby precise point positioning (PPP) or real-time kinematic (RTK) users can directly use the corrections from all or some of the stations for real-time precise positioning via a data server. At the user receiver, PPP and RTK techniques are unified under the same observation models, and the distinction is how the user receiver software deals with corrections from the reference station solutions and the ambiguity estimation in the observation equations. Numerical tests demonstrate good convergence behaviour for differential code bias and ambiguity estimates derived individually with single reference stations. With station-based solutions from three reference stations within distances of 22–103 km the user receiver positioning results, with various schemes, show an accuracy improvement of the proposed station-augmented PPP and ambiguity-fixed PPP solutions with respect to the standard float PPP solutions without station augmentation and ambiguity resolutions. Overall, the proposed reference station-based GNSS computing mode can support PPP and RTK positioning services as a simpler alternative to the existing network-based RTK or regionally augmented PPP systems. 相似文献
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简要介绍了天宝GNSS原始观测数据和RINEX格式数据的特点,对目前可用的天宝GNSS原始数据转换为RINEX格式的软件进行了详细的说明,并利用Python语言实现了批量转换,满足了测绘、国土等行业对于大量天宝观测数据转换的需求。 相似文献
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目前尚无一种GNSS数据质量检测软件可以兼容RINEX格式第二版和第三版、同时兼容四大导航卫星系统,严重滞后于GNSS的发展。基于MATLAB语言研发了一种新的数据质量检测软件BQC,不仅可以处理单观测文件,还可以对多个观测文件进行批处理;可以输出四大导航卫星系统的卫星角度位置、多径误差、电离层延迟、载噪比和周跳等信息及统计报告,在批处理模式下还可对多观测文件的数据质量进行比对;与TEQC相比具有较强的兼容性、算法优越性和直观性。随着四大导航系统的逐步完善和RINEX格式第三版的推广使用,该软件将会为GNSS的建设成果检验工作提供一种有力的支撑工具。 相似文献
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Both static and kinematic testings are investigated by using IGS 5min, 30s and 5s-interval precise satellite clock products
in precise point positioning (PPP) solution. Test results show that the sampling rate of IGS satellite clock has very little
effect on the static PPP solution. All the three types of sampling intervals of precise satellite clock can satisfy mm-cm
level of positioning accuracy; higher sampling rate has no significant improvement for PPP solution. However, sampling rate
of satellite clock has a significant impact on the PPP solution in kinematic PPP. The higher the interval of satellite clock,
the better the accuracy achieved. The accuracy of kinematic PPP achieved by using 30s-interval precise satellite clock is
improved by nearly 30–50 percent with respect to the solution by using 5min-interval precise satellite clock, but using 5s
and 30s-interval satellite clock can almost produce the same accuracy of kinematic solution. Moreover, the use of precise
satellite clock products from different analysis centers may also produce more or less effect on the PPP solution. 相似文献
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Both static and kinematic testings are investigated by using IGS 5min, 30s and 5s-interval precise satellite clock products in precise point positioning (PPP) solution. Test results show that the sampling rate of IGS satellite clock has very little effect on the static PPP solution. All the three types of sampling intervals of precise satellite clock can satisfy mm-cm level of positioning accuracy; higher sampling rate has no significant improvement for PPP solution. However, sampling rate of satellite clock has a significant impact on the PPP solution in kinematic PPP. The higher the interval of satellite clock, the better the accuracy achieved. The accuracy of kinematic PPP achieved by using 30s-interval precise satellite clock is improved by nearly 30–50 percent with respect to the solution by using 5min-interval precise satellite clock, but using 5s and 30s-interval satellite clock can almost produce the same accuracy of kinematic solution. Moreover, the use of precise satellite clock products from different analysis centers may also produce more or less effect on the PPP solution. 相似文献
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刘涛 《测绘与空间地理信息》2007,30(4):116-120
结合工程实例论述了国内外精密单点定位技术的研究现状,采用精密单点定位软件TriP处理静态观测数据,分析结果表明精密单点定位技术的定位精度和作业方法非常适合1∶10 000比例尺地形图测绘工作,将在新疆基础测绘工作中得到广泛应用。 相似文献
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本文基于非差精密单点定位(PPP)和双差定位模式,采用研制的UNIP软件和GAMIT/TRACK运动学分析模块,对GPS技术在地震监测中的应用进行研究。利用IGS不同精度和时延的星历和钟差产品,分析了卫星轨道和钟差对两种软件动态定位结果的影响;采用不同的数据处理方案,分别提取GPS同震地表形变信息。结果表明:GAMIT/TRACK模块精密动态定位的实时性,更适用于地震等突发事件中的GPS快速响应;如果能够提供精确的卫星钟差,UNIP软件的高程精度明显优于GAMIT/TRACK模块,技术将更显优势。 相似文献
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针对当前智能手机的全球卫星导航系统(GNSS)原始数据质量不佳导致常规精密单点定位(PPP)模型无法有效利用以及缺少智能手机PPP模型测试分析资料等问题,该文以载波加钟差的改进精密单点定位模型为基础,扩展至相应的载波加钟速模型、UofC模型、无模糊度模型、载波二次差模型及星间差分模型,简述了各个模型的特点,并利用华为P10智能手机的GNSS原始数据,测试并分析了各个模型定位精度情况:星间差分PPP模型在短期内(10 min)定位精度最优,平面中误差在1.8 m左右,高程2.1 m左右;改进模型与载波加钟速模型定位精度相当,UofC模型精度稍差;无模糊度模型与载波二次差模型需在Kalman滤波过程中采用降权方式防止其发散,定位精度取决于前期历元的数据质量。 相似文献
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GLONASS precise point positioning (PPP) performance is affected by the inter-frequency biases (IFBs) due to the application of frequency division multiple access technique. In this contribution, the impact of GLONASS pseudorange IFBs on convergence performance and positioning accuracy of GLONASS-only and GPS + GLONASS PPP based on undifferenced and uncombined observation models is investigated. Through a re-parameterization process, the following four pseudorange IFB handling schemes were proposed: neglecting IFBs, modeling IFBs as a linear or quadratic polynomial function of frequency number, and estimating IFBs for each GLONASS satellite. One week of GNSS observation data from 132 International GNSS Service stations was selected to investigate the contribution of simultaneous estimation of GLONASS pseudorange IFBs on GLONASS-only and combined GPS + GLONASS PPP in both static and kinematic modes. The results show that considering IFBs can speed up the convergence of PPP using GLONASS observations by more than 20%. Apart from GLONASS-only kinematic PPP, the positioning accuracy of GLONASS-only and GPS + GLONASS PPP is comparable among the four schemes. Overall, the scheme of estimating IFBs for each GLONASS satellite outperforms the other schemes in both convergence time reduction and positioning accuracy improvement, which indicates that the GLONASS IFBs may not strictly obey a linear or quadratic function relationship with the frequency number. 相似文献
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采用GNSS精密单点定位(PPP)技术和时钟驯服技术,构建了基于PPP的云平台高精度授时方案,研制了搭载多系统GNSS接收机板卡、恒温晶振(OCXO)和数字信号处理器(DSP)的授时原理样机。利用协同精密定位平台分析中心(武汉)提供的5 s间隔卫星轨道和钟差产品,采用PPP技术实时解算授时终端坐标和钟差,通过驯服恒温晶振输出亚纳秒精度的1 PPS,实现了长时间高精度的授时能力。本文通过短基线比较和与UTC绝对时间基准比较,验证了精密单点授时精度(RMS)优于1 ns。 相似文献
17.
BDS/GPS精密单点定位收敛时间与定位精度的比较 总被引：5，自引：1，他引：4
采用武汉大学卫星导航定位技术研究中心发布的北斗精密卫星轨道和钟差,在TriP 2.0软件的基础上实现了BDS PPP定位算法,并利用大量实测数据进行了BDS/GPS静态PPP和动态PPP浮点解试验。结果表明,BDS静态PPP的收敛时间约为80min,动态PPP的收敛时间为100min;对于3h的观测数据,静态PPP收敛后定位精度优于5cm,动态PPP收敛后水平方向优于8cm,高程方向约12cm;与GPS PPP类似,东分量上定位精度较北分量稍差。当前由于BDS的全球跟踪站有限,精密轨道和钟差精度不如GPS,因此BDS PPP的收敛时间较GPS长,但收敛后可实现厘米至分米级的绝对定位。 相似文献
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Kinematic positions of Low Earth Orbiters based on GPS tracking are frequently used as pseudo-observations for single satellite gravity field determination. Unfortunately, the accuracy of the satellite trajectory is partly limited because the receiver synchronization error has to be estimated along with the kinematic coordinates at every observation epoch. We review the requirements for GPS receiver clock modeling in Precise Point Positioning (PPP) and analyze its impact on kinematic orbit determination for the two satellites of the Gravity Recovery and Climate Experiment (GRACE) mission using both simulated and real data. We demonstrate that a piecewise linear parameterization can be used to model the ultra-stable oscillators that drive the GPS receivers on board of the GRACE satellites. Using such a continuous clock model allows position estimation even if the number of usable GPS satellites drops to three and improves the robustness of the solution with respect to outliers. Furthermore, simulations indicate a potential accuracy improvement of the satellite trajectory of at least 40 % in the radial direction and up to 7 % in the along-track and cross-track directions when a 60-s piecewise linear clock model is estimated instead of epoch-wise independent receiver clock offsets. For PPP with real GRACE data, the accuracy evaluation is hampered by the lack of a reference orbit of significantly higher accuracy. However, comparisons with a smooth reduced-dynamic orbit indicate a significant reduction of the high-frequency noise in the radial component of the kinematic orbit. 相似文献