共查询到20条相似文献，搜索用时 94 毫秒
1.
Calculation and accuracy evaluation of TGD from IFB for BDS 总被引：1，自引：0，他引：1
With the development of new global navigation satellite system applications, the demand of high accurate positioning navigation timing (PNT) service becomes urgent. For precise PNT, the timing group delay (TGD) is regarded as an important parameter in the satellite navigation message. Instead of using the absolute receiver hardware delay, a method based on receiver inter-frequency bias (IFB, i.e., differential receiver hardware delay between different frequencies) calibration is presented to deal with the rank deficiency of a calculation matrix and to reduce jumps in TGD solutions in BDS. The double-differenced pseudorange obtained from a pair of zero baseline receivers is used to evaluate the IFB calibration accuracy. The estimated precision of TGD is evaluated and compared with GPS TGD provided by IGS. In order to ensure the quality of assessment, a method based on the difference of dual-frequency ionospheric delay is proposed to compare the accuracy of the estimated TGD and broadcast TGD. Finally, the effect of TGD on the user equivalent range error is analyzed. The analysis result shows that for BDS IGSO satellites, the precision of TGD1, which is the differential hardware delay between B1 (1561.098 MHz) and B3 (1268.52 MHz) frequencies, is better than 0.5 ns, and for GEO and MEO satellites the TGD1 is better than 1 and 2 ns, respectively. The precision of TGD2 of all satellites, which is the differential hardware delay between B2 (1207.14 MHz) and B3 frequencies, is better than 0.5 ns. The accuracy analysis result reveals that the proposed TGD estimation method can provide better results when compared with the broadcast data. 相似文献
2.
GPS网络差分方法与实验 总被引：2，自引：1，他引：1
GPS连续运行站由于具有多种优势,所以在我国逐步建立,并开始得到广泛应用。但对于距离基准站较远,且位于基准站网一侧的情况下,该如何进行高精度的实时/快速卫星定位?本文给出了一种GPS网络差分方法,通过该方法可实现远海的高精度实时/快速GPS定位。最后,模拟远海应用情况进行实测试验,实验结果证明:在基准站距离200~300km的情况下,用户在距离基准站网400km一侧的范围内,采用双频机可实现优于2m的实时高精度定位,5min快速静态的水平精度优于1m,观测20min可到达优于0.5m的水平定位精度。 相似文献
3.
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
4.
采用IGS、MGEX、北斗地基增强网的实时观测数据,研制北斗广域精密定位服务系统,实时生成北斗高精度轨道、钟差、电离层产品,提供厘米级北斗双频PPP、分米级单频PPP、米级单频伪距定位服务。对实时产品评估分析的结果表明:北斗卫星实时轨道与钟差产品URE统计精度约为2.0cm,实时电离层精度优于4.0TECU。采用全国分布的实时测站动态定位精度(95%置信度)评估分析表明:北斗双频PPP精度存在明显的区域特征,高纬度以及西部边缘地区的定位精度平面约0.2m,高程约0.3m;中部地区定位精度平面优于0.1m,高程优于0.2m,接近GPS实时PPP精度水平;北斗与GPS融合可以提高单北斗、单GPS的定位性能,尤其是显著加快了PPP收敛时间,收敛时间缩短到20min内。另外,除边缘地区外,北斗单频PPP实现平面0.5m,高程1.0m;北斗单频伪距单点定位实现平面2.0m,高程3.0m。 相似文献
5.
GPS接收机天线相位中心偏差的三维检定研究 总被引：11，自引：1，他引：11
根据GPS接收机天线相位中心的几何关系，在超短基线相对定位法的基础上，利用旋转天线，结合精密水准测量，给出了一种天线相位中心偏差三雏检验的方法。实例表明，该方法具有较高的精度和可靠性，适合于在野外对GPS接收机天线相位中心偏差进行实际检定。 相似文献
6.
7.
实时GNSS精密单点定位(PPP)技术必须使用实时的高精度卫星精密轨道和钟差。本文研究了精密卫星钟差融合解算模型及策略,并利用滤波算法实现了北斗/GPS实时精密卫星钟差融合估计算法。仿真实时试验结果显示:获得的北斗/GPS实时钟差与GFZ事后多GNSS精密钟差(GBM)的标准差在0.15 ns左右;使用该钟差进行GPS动态PPP试验,收敛后水平精度优于5 cm,高程精度优于10 cm;使用仿真实时钟差进行的北斗动态PPP与使用GFZ事后多GNSS精密钟差开展的试验相比精度相当,可实现分米级定位。 相似文献
8.
9.
GPS RMBS(Relative Moving Baseline System)在工程中有许多重要的应用,例如,远洋编队航行、舰载飞机着舰、编队飞行、空中加油等,但在RMBS中需要伪距单点定位来提供起算点。本文讨论了伪距单点实时定位的精度,由于其精度有限,导出了该起算偏差对定位影响的模型。通过实验,其实算结果表明:由伪距实时单点定位来作为起算点,无论对于基线长还是基线分量都有影响,并且对基线分量的影响大于总基线,但对于10km范围内,其影响仍可以满足cm级高精度的相对定位要求。 相似文献
10.
北斗导航系统精密单点定位在地壳运动监测中的应用分析 总被引：1，自引：1，他引：0
主要基于7个台站观测到的BDS/GPS双模连续观测数据,时间跨度在2 a以上,利用武汉大学自主研发的PANDA软件的精密单点定位模式,对比分析了BDS/GPS双模观测数据的单系统定位精度,并探讨了BDS在地壳运动监测中的能力。通过对这些观测数据的解算及分析,结果表明,BDS在水平向的定位精度约为17 mm,垂向定位精度约为40 mm;GPS在水平向的定位精度要优于10 mm,垂向定位精度约为14 mm。基线统计结果显示,BDS检测弱信号的能力要低于GPS,但仍能够准确反映站点间基线长度和变化率特征。对比分析BDS和GPS得到的速度场,结果显示,两套速度场在水平向之间差值约为1~2 mm/a,且不存在系统性的差异。总体来看,虽然目前BDS精密单点定位精度要低于GPS,但是BDS目前仍可以用于监测形变量较大的地区地壳运动。 相似文献
11.
Phase variations of GPS receiving antennas are a significant error component in precise GPS applications. A calibration procedure
has been developed by Geo++ and the Institut für Erdmessung, which directly determines absolute phase center variations (PCVs)
without any multipath influence by field measurements. The precision and resolution of the procedure allows the determination
of reliable azimuthal variations. PCV may affect long-term static GPS differently than real-time GPS, depending on the applications.
At the same time, different antenna types are involved. Less investigations have been done on absolute PCV of rover antennas
than on geodetic antennas which, however, becomes more important due to the mixed antenna situation in GPS reference networks
and RTK networks. The concepts of the absolute PCV field calibration are summarized and emphasis is placed on a variety of
absolute PCV patterns of geodetic and rover antennas.
Electronic Publication 相似文献
12.
随着大众市场对高精度定位需求增加,基于低成本小型化设备的全球卫星导航系统(GNSS)高精度定位成为研究热点之一. 本文以低成本多系统GNSS接收机μ-blox M8P型号为例,分析其观测数据质量,研究其伪距单点定位和单频载波相对定位的定位性能和特点,为低成本GNSS接收机高精度定位应用提供参考. 实验结果表明,与测量型接收机相比,μ-blox输出GNSS观测值的载噪比略小,伪距和载波相位的测量噪声较大. 静态模式下,μ-blox的单频载波相对定位(基线长度约为430 m)可以提供厘米级的定位精度;城市环境动态模式下,其单频载波相对定位可提供亚米级至米级的定位精度. 信号受限环境下,GPS／GLONASS双系统能够提供更稳定的定位结果. 相似文献
13.
吴继忠 《武汉大学学报(信息科学版)》2012,37(5):617-620
分析了GPS天线积雪对载波信号场强、功率的影响,推导了载波信号传播延迟的简化计算公式,利用精密单点定位(PPP)计算了测站在GPS天线积雪产生和消除前后的单日解。结果显示,天线积雪使得天线相位中心产生偏移,对平面和高程方向的影响为数个cm,甚至更大。 相似文献
14.
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
15.
Absolute Positioning with Single-Frequency GPS Receivers 总被引：11，自引：3，他引：11
Ola Øvstedal 《GPS Solutions》2002,5(4):33-44
The use of precise post-processed satellite orbits and satellite clock corrections in absolute positioning, using one GPS
receiver only, has proven to be an accurate alternative to the more commonly used differential techniques for many applications
in georeferencing.
The absolute approach is capable of centimeter accuracy when using state-of-the-art, dual-frequency GPS receivers. When using
observations from single-frequency receivers, however, the accuracy, especially in height, decreases. The obvious reason for
this degradation in accuracy is the effect of unmodeled ionospheric delay.
This paper discusses the availability of some empirical ionospheric models that are publicly available and quantifies their
usefulness for absolute positioning using single-frequency GPS receivers. The Global Ionospheric Model supplied by International
GPS Service (IGS) is the most accurate one and is recommended for absolute positioning using single-frequency GPS receivers.
Using high-quality single-frequency observations, a horizontal epoch-to-epoch accuracy of better than 1 m and a vertical accuracy
of approximately 1 m is demonstrated. ? 2002 Wiley Periodicals, Inc. 相似文献
16.
提出一种基于单频码和相位观测量的单频精密单点定位方法,将每个观测量的电离层延迟量与接收机钟差、对流层天顶延迟、接收机位置、相位模糊度一起作为未知参数。采用约化参数的平方根信息滤波与平滑算法进行参数解算。该方法适用于实时定位和事后处理,且不需要外部的电离层模型。采用全球分布的32个IGS监测站16 d实测数据进行静态解算试验,结果表明E、N、U方向的RMS分别为0.023 m、0.018 m、0.059 m;基于一组机载GPS数据进行动态解算试验,得到E、N、U方向的RMS(与载波相位动态相对定位结果比较)分别为0.168 m、0.151 m、0.172 m。 相似文献
17.
18.
Time-relative positioning makes use of observations taken at two different epochs and stations with a single global positioning
system (GPS) receiver to determine the position of the unknown station with respect to the known station. The limitation of
this method is the degradation over time of the positioning accuracy due to the temporal variation of GPS errors (ionospheric
delay, satellite clock corrections, satellite ephemerides, and tropospheric delay). The impact of these errors is significantly
reduced by adding to the one-way move from the known to the unknown station, a back move to the known station. A loop misclosure
is computed from the coordinates obtained at the known station at the beginning and at the end of the loop, and is used to
correct the coordinates of the unknown station. The field tests, presented in this paper, show that using the loop misclosure
corrections, time-relative positioning accuracy can be improved by about 60% when using single frequency data, and by about
40% with dual frequency data. For a 4-min processing interval (an 8-min loop) and a 95% probability level, errors remain under
20 cm for the horizontal components and 36 cm for the vertical component with single frequency data; and under 11 cm for the
horizontal components and 29 cm for the vertical component with dual frequency data. 相似文献
19.
多传感器与道路网数据用于汽车导航的研究 总被引：4，自引：0，他引：4
对车载导航系统中GPS接收机，车论计数器和电子罗盘传感器数据与导航电子地图所提供的道路网络数据进行了综合处理，建立了道路网络数据的网络拓扑关系，在此基础上提出了基于道路网络拓扑关系，利用GPS接收机，车轮计数器和电子罗盘传感器对汽车进行实时定位的算法。最后，对导航中汽车的定位误差进行了分析。实验证明，GPS接收机，车轮计数器和电子罗盘传感器与道路网络数据综合，在导航过程中能够补偿GPS信号技失，实时、高精度、高可靠性地确定汽车的位置。 相似文献
20.
Phase center modeling for LEO GPS receiver antennas and its impact on precise orbit determination 总被引：7，自引：5，他引：7
Adrian Jäggi R. Dach O. Montenbruck U. Hugentobler H. Bock G. Beutler 《Journal of Geodesy》2009,83(12):1145-1162
Most satellites in a low-Earth orbit (LEO) with demanding requirements on precise orbit determination (POD) are equipped with
on-board receivers to collect the observations from Global Navigation Satellite systems (GNSS), such as the Global Positioning
System (GPS). Limiting factors for LEO POD are nowadays mainly encountered with the modeling of the carrier phase observations,
where a precise knowledge of the phase center location of the GNSS antennas is a prerequisite for high-precision orbit analyses.
Since 5 November 2006 (GPS week 1400), absolute instead of relative values for the phase center location of GNSS receiver
and transmitter antennas are adopted in the processing standards of the International GNSS Service (IGS). The absolute phase
center modeling is based on robot calibrations for a number of terrestrial receiver antennas, whereas compatible antenna models
were subsequently derived for the remaining terrestrial receiver antennas by conversion (from relative corrections), and for
the GNSS transmitter antennas by estimation. However, consistent receiver antenna models for space missions such as GRACE
and TerraSAR-X, which are equipped with non-geodetic receiver antennas, are only available since a short time from robot calibrations.
We use GPS data of the aforementioned LEOs of the year 2007 together with the absolute antenna modeling to assess the presently
achieved accuracy from state-of-the-art reduced-dynamic LEO POD strategies for absolute and relative navigation. Near-field
multipath and cross-talk with active GPS occultation antennas turn out to be important and significant sources for systematic
carrier phase measurement errors that are encountered in the actual spacecraft environments. We assess different methodologies
for the in-flight determination of empirical phase pattern corrections for LEO receiver antennas and discuss their impact
on POD. By means of independent K-band measurements, we show that zero-difference GRACE orbits can be significantly improved
from about 10 to 6 mm K-band standard deviation when taking empirical phase corrections into account, and assess the impact
of the corrections on precise baseline estimates and further applications such as gravity field recovery from kinematic LEO
positions. 相似文献