共查询到20条相似文献，搜索用时 31 毫秒
1.
高精度GPS城市沉降监测网的数据处理与精度分析 总被引：4，自引：1，他引：4
为了研究用GPS观测取代常规的水准测量方法来监测城市沉降变化的可行性，在宁波市建立了有7个点组成的GPS基准网和14个点组成的GPS监测网。在观测中采取了一定的措施，以获得高精度的高程分量。用Bernese软件对数据进行处理时顾及到对流层延迟的影响，采用Saastamoinen模型，获得了mm级的高程精度，这将有助于提高沉降监测的效率。 相似文献
2.
GPS信号对流层延迟改正新模型研究 总被引：7，自引：0，他引：7
为削弱对流层对GPS精密定位的影响，从大气折射率入手将大气分为3层，建立了大气折射率模型，并导出了对流层天顶延迟模型。利用IGS跟踪站的实测数据进行了验证，实验证明了新模型的有效性。 相似文献
3.
GPS/VRS 参考站网络的对流层误差建模技术研究 总被引：5，自引：1，他引：4
在虚拟参考站(VRS)技术中,参考站与流动站间的高程差异会引起对流层误差改正数中存在系统偏差影响,使对流层改正精度降低。在常规网络内插改正模型的基础上,借助先验对流层模型,提出了一种能自主修正高程偏差的距离相关对流层网络内插模型(MHDIM)。基于四川GPS连续运行参考站网络(Sichuan GPS Reference Station Network-SGRSN)实际测试数据的分析表明,对于地形变化较大的中长距离稀疏GPS/VRS参考站网络(如流动站与参考站间高程差异大于500m),应用MHDIM模型可使对流层延迟误差改正精度提高到2到3cm并实现cm级网络RTK定位结果,适用于GPS/VRS参考站网络cm级实时动态定位要求。 相似文献
4.
无气象要素的GPS对流层延迟推算可降水量的研究 总被引：2，自引：0，他引：2
本文针对武汉地区GPS气象网资料,进行了GPS对流层延迟直接推算可降水量的研究。在武汉东湖站GPS对流层延迟与无线电探空可降水量的比较中,两者具有很好的相关性,相关系数达到了0.93;推导了对流层延迟直接推算可降水量的模型,对模型结果进行了检验,在武汉东湖站的对流层延迟转换的可降水量与无线电探空可降水量的比较中,均方根为7.8mm,相关性为0.91,这说明了在没有气象数据的地区对流层延迟直接推算的可降水量可以作为气象短期预报的参考。 相似文献
5.
我国高精度GPS陆海垂直运动监测网的数据处理 总被引：4，自引：0，他引：4
为了分离海平面与验潮站所在陆地的垂直运动并获得海平面变化的绝对信息 ,对由沿海 5个验潮站组成的高精度 GPS陆海垂直运动监测网的 1998年一期观测数据 ,采用 GAMIT和 GL OBK软件进行了处理 ,并顾及了影响高程因素中由于方位不对称引起的大气延迟及改进的 Niell模型。最终 GPS监测网达到了毫米级的高程精度。 相似文献
6.
7.
Steffen Schön 《GPS Solutions》2007,11(2):107-117
GPS is a promising tool for real-time monitoring of deformations of slopes or large structures. However, remaining systematic
effects in GPS phase observations after double differencing and application of a priori models affect the resulting coordinates.
They complicate the proper separation of the actual deformations from pseudo-deformations induced by the systematic effects.
This paper shows that for small monitoring networks (baseline lengths <5 km) only affine distortions of the network geometry
are generated by the remaining distance dependent systematic effects, e.g. unmodelled tropospheric and ionospheric propagation
effects, or satellite orbit errors. Hence, a generic correction model is given by a three-dimensional affine transformation
involving a maximum of 12 transformation parameters. For the determination of these parameters, four high quality GPS stations
are necessary which are not affected by the actual deformations to be monitored. Based on the analysis of network geometries
of synthetic GPS networks with large height differences and considering the physics of the GPS observations it is shown, however,
that less than 12 parameters are sufficient for the computation of the corrections. The proposed 8 parameter model was applied
to the GPS monitoring network of the Gradenbach landslide. For this small network with large height differences, it was shown
that the distortions can be reduced by about 75%. 相似文献
8.
电离层延迟是单频GPS地面沉降监测点的最主要误差源,如何削弱该误差的影响是提高单双频混合地面沉降监测系统精度的关键。采用中国广州南沙单双频混合GPS地面沉降监测网数据进行处理分析,结果表明,在低纬度地区即使基线较短,电离层延迟对单频GPS监测精度影响仍然较大,影响程度随基线长度增加而增大,而且在时间域上有明显的季节性变化规律:2、3月份与8、9月份电离层影响较为显著。利用双频点数据从观测值域对单频点电离层延迟误差进行改正,监测精度提高了57%,改善效果明显。 相似文献
9.
Precise estimation of residual tropospheric delays using a regional GPS network for real-time kinematic applications 总被引：7，自引：0，他引：7
A new method called Trop_NetAdjust is described to predict in real time the residual tropospheric delays on the GPS carrier
phase observables using the redundant measurements from a network of GPS reference stations. This method can not only enhance
the effectiveness and reliability of real-time kinematic users within the network, but also provide a valid approach to tropospheric
parameter variation forecasting. Trop_NetAdjust is theoretically based upon LS prediction criteria and enables the prediction
of residual tropospheric delays remaining after a standard model has been applied to the raw GPS measurements. Two cases are
analyzed, namely a first case when the delay is required for an existing satellite at a new point within the network and a
second case when the delay is required for a new satellite. Field tests were conducted using data collected in a network of
11 reference stations covering a 400×600 km region in southern Norway. The results were analyzed in the measurement domain
(ionospheric-free double-difference residuals) and showed improvements of 20 to 65% RMS errors using Trop_NetAdjust. The estimates
of the Trop_NetAdjust prediction accuracy were also obtained using the covariance analysis method. The agreement was consistently
better than 30% when compared with data from a real network.
Received: 28 February 2000 / Accepted: 9 January 2001 相似文献
10.
During past decades, precise point positioning (PPP) has been proven to be a well-known positioning technique for centimeter or decimeter level accuracy. However, it needs long convergence time to get high-accuracy positioning, which limits the prospects of PPP, especially in real-time applications. It is expected that the PPP convergence time can be reduced by introducing high-quality external information, such as ionospheric or tropospheric corrections. In this study, several methods for tropospheric wet delays modeling over wide areas are investigated. A new, improved model is developed, applicable in real-time applications in China. Based on the GPT2w model, a modified parameter of zenith wet delay exponential decay wrt. height is introduced in the modeling of the real-time tropospheric delay. The accuracy of this tropospheric model and GPT2w model in different seasons is evaluated with cross-validation, the root mean square of the zenith troposphere delay (ZTD) is 1.2 and 3.6 cm on average, respectively. On the other hand, this new model proves to be better than the tropospheric modeling based on water-vapor scale height; it can accurately express tropospheric delays up to 10 km altitude, which potentially has benefits in many real-time applications. With the high-accuracy ZTD model, the augmented PPP convergence performance for BeiDou navigation satellite system (BDS) and GPS is evaluated. It shows that the contribution of the high-quality ZTD model on PPP convergence performance has relation with the constellation geometry. As BDS constellation geometry is poorer than GPS, the improvement for BDS PPP is more significant than that for GPS PPP. Compared with standard real-time PPP, the convergence time is reduced by 2–7 and 20–50% for the augmented BDS PPP, while GPS PPP only improves about 6 and 18% (on average), in horizontal and vertical directions, respectively. When GPS and BDS are combined, the geometry is greatly improved, which is good enough to get a reliable PPP solution, the augmentation PPP improves insignificantly comparing with standard PPP. 相似文献
11.
对流层延迟是GPS定位的主要误差源之一，一直是高精度GPS定位的障碍。本文针对湿分量延迟计算复杂，影响因素多，经模型改正后也不理想的现实情况，巧妙的使用IGS产品推算对流层延迟湿分量，进一步削弱了GPS定位中对流层延迟的影响，得出了一些有益的结论。 相似文献
12.
Manuela Krügel Daniela Thaller Volker Tesmer Markus Rothacher Detlef Angermann Ralf Schmid 《Journal of Geodesy》2007,81(6-8):515-527
The combination of tropospheric parameters derived from different space-geodetic techniques has not been of large interest
in geodesy so far. However, due to the high correlation between station coordinates and tropospheric parameters, the latter
should not be neglected in combinations. This paper deals with the comparison and combination of tropospheric parameters derived
from global positioning system (GPS) and very long baseline interferometry (VLBI) observations stemming from a 15-day campaign
of continuous VLBI observations in 2002 (CONT02). The observation data of both techniques were processed homogeneously to
avoid systematic differences between the solutions. We compared the tropospheric estimates of GPS and VLBI at eight co-location
sites and found a very good agreement in the temporal behavior of the tropospheric zenith path delays (ZPD), reflected by
correlation factors up to 0.98. Following this, a combination of the tropospheric parameters was performed. We demonstrate
that the combination of tropospheric parameters leads to a stabilization of combined station networks. This becomes visible
in the improvement of the repeatabilities of the station height components. Furthermore, the potential use of independent
data from water vapor radiometers (WVRs) to validate space-technique-derived tropospheric parameters was investigated. Correlation
coefficients of 0.95 or better were estimated between the tropospheric parameters of WVR and GPS or VLBI. Additionally, the
utility of the tropospheric parameters for validation of local tie vectors was investigated. Both tropospheric zenith delays
and tropospheric gradients were found to be very suitable to validate the height component and the horizontal components of
the local tie, respectively. 相似文献
13.
Hadas Tomasz Teferle Felix Norman Kazmierski Kamil Hordyniec Pawel Bosy Jaroslaw 《GPS Solutions》2017,21(3):1069-1081
GPS Solutions - In GNSS data processing, the station height, receiver clock and tropospheric delay (ZTD) are highly correlated to each other. Although the zenith hydrostatic delay of the... 相似文献
14.
以华南沿海地区短基线GNSS-C级网为例,使用GAMIT软件,分别采用对流层延迟估计与对流层延迟不估计的解算策略,选取丘陵地区、海岛地区、平原地区三个区域短基线向量数据作为样例,比较分析两种策略在不同地理环境下的短基线数据解算精度,并结合整个短基线全球卫星导航系统（GNSS）控制网的数据进行解算分析．试验结果显示,对流层延迟估计与对流层延迟不估计的解算策略在三个区域的基线U分量精度均良好,但后者精度优于前者．整网的基线重复性方面,对流层延迟估计与对流层延迟不估计的解算策略精度均良好,但前者精度略优于后者. 相似文献
15.
A grid-based tropospheric product for China using a GNSS network 总被引：1，自引：0，他引：1
Tropospheric delay accounts for one source of error in global navigation satellite systems (GNSS). To better characterize the tropospheric delays in the temporal and spatial domain and facilitate the safety-critical use of GNSS across China, a method is proposed to generate a grid-based tropospheric product (GTP) using the GNSS network with an empirical tropospheric model, known as IGGtrop. The prototype system generates the GTPs in post-processing and real-time modes and is based on the undifferenced and uncombined precise point positioning (UU-PPP) technique. GTPs are constructed for a grid form (\(2.0{^{\circ }}\times 2.5{^{\circ }}\) latitude–longitude) over China with a time resolution of 5 min. The real-time GTP messages are encoded in a self-defined RTCM3 format and broadcast to users using NTRIP (networked transport of RTCM via internet protocol), which enables efficient and safe transmission to real-time users. Our approach for GTP generation consists of three sequential steps. In the first step, GNSS-derived zenith tropospheric delays (ZTDs) for a network of GNSS stations are estimated using UU-PPP. In the second step, vertical adjustments for the GNSS-derived ZTDs are applied to address the height differences between the GNSS stations and grid points. The ZTD height corrections are provided by the IGGtrop model. Finally, an inverse distance weighting method is used to interpolate the GNSS-derived ZTDs from the surrounding GNSS stations to the location of the grid point. A total of 210 global positioning system (GPS) stations from the crustal movement observation network of China are used to generate the GTPs in both post-processing and real-time modes. The accuracies of the GTPs are assessed against with ERA-Interim-derived ZTDs and the GPS-derived ZTDs at 12 test GPS stations, respectively. The results show that the post-processing and real-time GTPs can provide the ZTDs with accuracies of 1.4 and 1.8 cm, respectively. We also apply the GTPs in real-time kinematic GPS PPP, and the results show that the convergence time of the PPP solutions is shortened. These results confirm that the GTPs can act as an efficient information source to augment GNSS positioning over China. 相似文献
16.
GPS定位中的对流层模型分析 总被引：1，自引：0，他引：1
系统地分析对流层延迟特性在GPS导航中造成的定位误差，并主要介绍目前卫星定位领域主要应用的一些对流层折射修正模型。基于霍普尔德模型和萨斯塔莫宁模型，提出一种在缺少实测气象参数条件下，使用的简单对流层延迟修正模型。利用Matlab仿真软件对静态和动态接收机实测数据进行分析。结果表明，无气象参数的简单修正模型可以消除70％左右的对流层影响，有效地提高GPS的定位精度。 相似文献
17.
A new approach for deformation monitoring of super high-rise building using GPS/BDS technology is proposed for the case when prior coordinates are known and the baseline is short but has a large height difference. The approach is based on the ambiguity function method (AFM). Considering that the double-differenced (DD) troposphere delay residual error cannot be ignored, the relative zenith tropospheric delay (RZTD) parameter is introduced into the original AFM equation. Thus, the RZTD and 3D coordinate parameters are together obtained through the modified AFM (MAFM). Due to the low computational efficiency of conventional AFM, an improved particle swarm optimization (IPSO) algorithm is used to search the four optimal parameters X/Y/Z/RZTD and replaces the grid search method. In this study, GPS/BDS deformation monitoring data for buildings with approximately 290 m height difference were used to verify the feasibility of the proposed MAFM. Numerical results show a single-epoch average computation time of approximately 0.3 s, which meets the requirements of near-real-time dynamic monitoring. The average accuracy of the GPS single-epoch RZTD solution is better than 1 cm, the combined GPS/BDS MAFM performance outperforms the GPS-only system, and using multi-epoch observations can further improve the accuracy of the RZTD solution. After RZTD correction, GPS/BDS monitoring precision can be improved, particularly the height dimension, whose precision is improved by approximately 6 cm. 相似文献
18.
A method based on multi-antennae linked to a common GPS receiver is proposed. The goal of the technique is to improve height determination for baselines a few kilometres in length. The advantage of this technique resides in the elimination of relative clock parameters in the between-antenna single difference observations. Because single difference observations are free of clock errors more geometrical strength remains to determine the baseline components. This statement is valid as long as intercable biases can be carefully calibrated. For millimetre height determination, the intercable calibration must be done at the same level of accuracy. Under this assumption it is shown that in general the height standard deviation improves by a factor of about three compared to standard GPS data processing. With the proposed method, the effect of relative tropospheric zenith delay errors becomes a bit smaller (in absolute value), compared to standard data processing. To absorb this error, a relative tropospheric zenith delay parameter may be estimated. Even with this additional parameter in the solution the height standard deviation remains two times smaller than the results of standard processing techniques (without tropospheric zenith delay parameter), and at least five times smaller than in the results obtained from standard processing including one tropospheric zenith delay parameter. 相似文献
19.