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1.
用PPP技术确定南极Amery冰架的三维运动速度 总被引：11，自引：4，他引：11
基于GPS精密点定位(precise point positioning,PPP)技术,利用IGS的精密星历数据编制软件处理了在Amery冰架获取的连续5d的GPS卫星跟踪观测资料,初步获得了冰架前端观测点处的冰流速度和冰流方向。根据定位解算出的高程系列的周期变化,初步推求出观测点处的海潮周日变化参数。研究成果可为后续的物质平衡计算提供依据。 相似文献
2.
The main activities in the joint expedition between CHINARE and ANARE on Amery ice shelf are introduced. Five-day continuous GPS observation data collected on the site which locates at the frontal part of Amery ice shelf was processed with precise point positioning (PPP) technology based on precise products from IGS. Velocity of the surface ice flow on Amery can be derived from the PPP solution. Preliminary result shows that the surface ice flow velocity of the site is 2.25 meters per day, the motion direction is northeast-ward. Semidiurnal oceanic tide and diurnal oceanic tide signal of that site can be recovered from the height variation series of PPP solution. These above solutions can be used to the consequent mass balance calculation. 相似文献
3.
ZHANG Xiaohong E Dongchen 《地球空间信息科学学报》2005,8(4):251-256
The main activities in the joint expedition between CHINARE and ANARE on Amery ice shelf are introduced. Five-day continuous GPS observation data collected on the site which locates at the frontal part of Amery ice shelf was processed with precise point positioning （PPP） technology based on precise products from IGS. Velocity of the surface ice flow on Amery can be derived from the PPP solution. Preliminary result shows that the surface ice flow velocity of the site is 2.25 meters per day, the motion direction is northeastward. Semidiurnal oceanic tide and diurnal oceanic tide signal of that site can be recovered from the height variation series of PPP solution. These above solutions can be used to the consequent mass balance calculation. 相似文献
4.
中山站至A冰穹考察及沿线GPS复测结果分析 总被引：5，自引：0，他引：5
南极中山站至A冰穹（Dome-A)考察沿线布设有GPS等精度定位点，通过用高精GPS静态定位处理软件GAMIT／GLOBK对三期观测数据的处理可知，考察沿线的GPS点以8－25m/a的速度向西北方向（冰盖边缘方向）流动，越接近冰盖边缘，运动速度赵快，最快达到100m/a；而且冰川整体上以1－5m/^2的加速度流动。同时，由冰盖的流动，引起了垂直方向0－2－1m/a的沉降速度。 相似文献
5.
利用GPS技术反演海潮负荷信息，相比传统重力及甚长基线干涉测量，有着全球覆盖、测站数多、全天候、成本低等诸多优势，为海潮模型的建立提供了有效的技术手段，也对海潮负荷效应的研究有着重要的理论意义和参考价值。利用动态精密单点定位技术（precise point positioning，PPP）反演海潮负荷位移，同时构建了区域海潮负荷位移模型。利用香港连续运行参考站8 a的GPS观测数据，精密测定了11个测站的三维海潮负荷位移参数，与高精度海潮模型提供的海潮负荷位移参数进行比较，发现除K2、K1潮波外，其他潮波的均方根误差均小于2 mm。与已有的动态PPP及静态PPP结果对比发现，采用改进的重叠时段动态PPP算法可有效改善K1潮波的反演精度；该方法反演的海潮负荷位移精度可达到静态PPP反演海潮负荷位移的精度，且对于K1潮波，在东西方向，动态PPP算法的反演精度较静态PPP略有改善。利用最小二乘曲面拟合法可有效建立中国香港地区GPS区域海潮负荷位移模型，可有效弥补沿海地区因验潮站稀少而导致的海潮模型适应性差的问题。 相似文献
6.
受特殊海岸线及复杂海底地形的影响,目前发布的全球海潮模型在局部沿海地区差异较大,需利用其他大地测量手段直接测定沿海地区的海潮负荷位移参数。GPS技术因具有全天候、精度高、成本低等优势,已成为获取海潮负荷位移参数的有效手段。本文基于GPS技术监测测站三维位移变化的灵敏度高于监测48个海潮参数的灵敏度这一基本思想,改进了利用GPS精密单点定位(PPP)技术估计48个海潮调和参数的方法,直接逐历元求解三维海潮负荷位移变化,再利用调和分析方法提取主要潮波(M2、S2、N2、K2、K1、O1、P1、Q1)的海潮负荷位移建模参数(振幅与相位)。利用12个香港连续运行参考站(CORS)8年的GPS观测数据,计算各测站的海潮负荷位移建模参数。与传统方法比较,本文方法可有效加速K1潮波在东西方向的收敛。将GPS海潮负荷位移建模参数估值与中国近海海潮模型值比较,发现除S2、K2和K1潮波的均方根误差较大外,其他潮波的均方根误差均小于1.5mm。将香港2008—2014年验潮站数据反演的潮波参数与海潮模型值比较,结果表明:GPS与验潮站数据反演的潮波参数均与中国近海海潮模型及HAMTIDE2011.11A全球海潮模型符合较好,验证了GPS PPP反演海潮负荷位移的有效性。采用GPS PPP估计的8个潮波的振幅与相位值替换全球海潮模型中对应的潮波值,进行海潮负荷效应改正,可减弱GPS长时间序列中的半周年信号。 相似文献
7.
Strategies for High Precision Processing of GPS Measurements with Application to the Amery Ice Shelf,East Antarctica 总被引：3，自引：0，他引：3
A number of statistic Global Positioning System (GPS) measurement campaigns have been made on a floating Antarctic ice shelf,
the Amery Ice Shelf, as part of ongoing glaciological studies designed to investigate the ice shelf dynamics, grounding zone
definition, and ice shelf strain. Such studies ar fundamental to improving out knowledge of the Antarctic ice-sheet mass balance
and dynamical models of ice sheet/ocean interaction. This article describes two techniques used to process the statistic GPS
data. One approach uses a segmented version of the classical static methodology, and the other approach adopts a new sequential
processing technique. Both approaches yield similar results for the station coordinates and demonstrate the potential of GPS
for extracting the tidal signal on the ice shelves and giving information on the dynamical motion of the ice sheet. To verify
our results for the vertical component, we compare the ice shelf GPS tidal signal with a tidal model derived from tide gauge
measurements at nearby Beaver Lake. Comparison of the GPS results with the tide model give good agreement in amplitude at
the few cm level (GPS results always larger) but clearly shows evidence of phase propagation of the ocean tidal wave under
the ice shelf. Improving the resolution of the tides over the ice shelves will be of tremendous benefit for future satellite
missions, such as Ice, Cloud and Land Elevation Satellite (ICESAT), and the integrated use of GPS and satellite data will
be fundamental for any on-going Antarctic ice sheet mass balance studies. ? 2000 John Wiley & Sons, Inc. 相似文献
8.
针对传统事后精密单点定位技术的时间延迟问题,该文基于IGS RTS实时数据流产品,开展了实时精密单点定位技术在远海实时GPS验潮中的应用研究.对RTS改正的实时精密卫星轨道和钟差进行了精度验证和分析,给出了RT-PPP的数据处理策略以及实时GPS验潮的基本流程;组织和实施了渤海湾船载GPS验潮试验,以压力式验潮仪数据为参考,对远距离实时GPS潮汐测量结果进行了精度分析.结果表明:①以IGS最终卫星轨道和钟差产品为参考,RTS实时精密卫星轨道在X、y、Z方向的精度(RMS)均优于3 cm,卫星钟差的精度优于0.15 ns;②采用傅里叶低通滤波方法,消除波浪对潮汐观测的影响,进一步提取潮位信息.在忽略船体姿态改正的情况下,实时精密单点定位验潮相对于压力式验潮仪结果的最大偏差优于20 cm,RMS达到7.5 cm. 相似文献
9.
目前国内外许多学者利用沿海GPS站点的高精度坐标时间序列进行海潮特征信息的提取研究,已取得一定成果,但高精度坐标时间序列中不可避免地存在许多噪声,极大影响海潮特征信息的提取。基于日本GMSD站的67d的高精度PPP坐标时间序列,利用小波分析进行去噪实验,经FFT变换后,将提取的结果与FES2004海潮模型的特征值比较。实验结果表明:经小波分析后,GPS站点的时间序列精度得到提高;经小波去噪后的反演精度均有不同程度的提高,最多达到0.14mm,而海潮特征值的量级为厘米级或者亚厘米级,说明小波分析对海潮特征值的提取精度有明显提高。 相似文献
10.
A combination of GPS and GLONASS observations can offer improved reliability, availability and accuracy for precise point positioning (PPP). We present and analyze a combined GPS/GLONASS PPP model, including both functional and stochastic components. Numerical comparison and analysis are conducted with respect to PPP based on only GPS or GLONASS observations to demonstrate the benefits of the combined GPS/GLONASS PPP. The observation residuals are analyzed for more appropriate stochastic modeling for observations from different navigation systems. An analysis is also made using different precise orbit and clock products. The performance of the combined GPS/GLONASS PPP is assessed using both static and kinematic data. The results indicate that the convergence time can be significantly reduced with the addition of GLONASS data. The positioning accuracy, however, is not significantly improved by adding GLONASS data if there is a sufficient number of GPS satellites with good geometry. 相似文献
11.
In recent years, ocean tide loading displacements (OTLD) have been measured using the Global Positioning System (GPS) and
Very Long Baseline Interferometry (VLBI). This study assesses the accuracy of GPS measurements of OTLD by comparison with
VLBI measurements and estimates derived from numerical ocean tide models. A daily precise point positioning (PPP) analysis
was carried out on ∼11 years of GPS data for each of 25 sites that have previous OTLD estimates based on data from co-located
VLBI sites. Ambiguities were fixed to integer values where possible. The resulting daily estimates of OTLD, at eight principal
diurnal and semi-diurnal tidal frequencies, were combined to give GPS measurements of OTLD at each site. The 3D GPS and VLBI
measurements of OTLD were compared with estimates computed (by convolution with Green’s functions) from five modern ocean
tide models (CSR4.0, FES2004, GOT00.2, NAO99b and TPXO6.2). The GPS/model agreement is shown to be similar to the VLBI/model
agreement. In the important radial direction, the GPS/model misfit is shown to be smaller than the VLBI/model misfit for seven
of the eight tidal constituents; the exception being the K2 constituent. Fixing of GPS carrier-phase ambiguities to integer
values resulted in a marginal improvement to the GPS/model agreement. Statistically, it is shown there is no significance
to the difference between the fit of the GPS and VLBI measurements of OTLD to modelled values. Equally, differences in fit
of either the complete set of GPS or VLBI estimates to the five sets of model-derived values cannot be identified with statistical
significance. It is thus concluded that, overall, we cannot distinguish between GPS and VLBI measurements of OTLD, and that
at the global scale, present ocean tide models are accurate to within the current measurement noise of these techniques. 相似文献
12.
Some GPS points were set up and occupied and reoccupied along the traverse route from Zhongshan Station to Dome-A.The result analysis for the GPS data processed by GAMIT/GLOBK package was presented in this paper.It was indicated that the ice along the traverse route flowed with an 8-25 m/a velocity to the northwest in the last three years,which was the direction of the edge of the ice sheet.The maximum horizontal flow velocity is about 100 m/a.Moreove,due to the ice flow,a 0.2-1 m/a sedimentation rate is achieved.finally,a 1-5m/a^2 horizontal acceleration is achieved from the GPS data of the three different stages. 相似文献
13.
利用动态精密单点定位技术,分析了日本仙台大地震对日本及中国境内若干GPS基准台站的影响。结果表明,采用动态精密单点定位技术能准确地反映GPS台站的受损程度,有效地探测地震发生时刻及其震后位移。 相似文献
14.
在GPS和GLONASS观测方程中考虑硬件延迟偏差的基础上,推导了GPS/GLONASS双系统组合精密单点定位的数学模型,并分析了硬件延迟偏差对估计的未知参数的影响。利用IGS跟踪站的观测数据和动态实验数据,对组合GPS/GLONASS精密单点定位模型进行了试算,并与GPS单系统精密单点定位的结果进行了比较。 相似文献
15.
GLONASS pseudorange inter-channel biases and their effects on combined GPS/GLONASS precise point positioning 总被引：6，自引：5，他引：1
Combined GPS/GLONASS precise point positioning (PPP) can obtain a more precise and reliable position than GPS PPP. However, because of frequency division multiple access, GLONASS carrier phase and pseudorange observations suffer from inter-channel biases (ICBs) which will influence the accuracy and convergence speed of combined GPS/GLONASS PPP. With clear understanding of the characteristics of carrier phase ICBs, we estimated undifferenced GLONASS pseudorange ICBs for 133 receivers from five manufacturers and analyzed their characteristics. In general, pseudorange ICBs corresponding to the same firmware have strong correlations. The ICB values of two receivers with the same firmware may be different because of different antenna types, and their differences are closely related to frequency. Pseudorange ICBs should be provided for each satellite to obtain more precise ICBs as the pseudorange ICBs may vary even on the same frequency. For the solutions of standard point positioning (SPP), after pseudorange ICB calibration, the mean root mean square (RMS) improvements of GLONASS SPP reach up to 57, 48, and 53 % for the East, North, and Up components, while combined GPS/GLONASS SPP reach up to 27, 17, and 23 %, respectively. The combined GPS/GLONASS PPP after pseudorange ICB calibration evidently improved the convergence speed, and the mean RMS of PPP improved by almost 50 % during the convergence period. 相似文献
16.
17.
The technique of precise point positioning (PPP) is gradually becoming a popular method in GPS data-processing. In GPS observation equation, the unknown parameters can be separated into two parts: global parameters and local parameters. The global parameters include orbit, satellite clock and geodynamic parameters. The local parameters are site-occupation-spectific, such as position, tropospheric delay, etc. The formulas of local parameters are firstly derived under the network-solution and the PPP-solution conditions respectively. If the weight matrix of global parameters in PPP-solution is small enough, the cofactor matrices of local parameters are the same as that in network-solution. Then, 16 daily solutions are obtained in both PPP mode and network mode. Three sites are selected to compare the solutions. The experimental results demonstrated that the difference between two solutions in coordinates and tropospheric delays are only few millimeters. This level of difference can be neglected so that the solutions from both PPP mode and network mode can be taken as the same in the actual application. 相似文献
18.
In the precise point positioning(PPP),some impossible accurately simulated systematic errors still remained in the GPS observations and will inevitably degrade the precision of zenith tropospheric delay(ZTD) estimation.The stochastic models used in the GPS PPP mode are compared.In this paper,the research results show that the precision of PPP-derived ZTD can be obviously improved through selecting a suitable stochastic model for GPS measurements.Low-elevation observations can cover more troposphere informat... 相似文献
19.
PENG Lin LIU Yanxiong ZHOU Xinghua WU Yongting 《地球空间信息科学学报》2006,9(2):99-102
IntroductionIn GPS data-processing, the most accurate andpopular method is to solve the unknown parametersbased on a GPS network which includes many GPSsites. This mode is always called network-solution.The network-solution makes use of the spatial geom-e… 相似文献
20.
探讨了精密单点定位的基本原理、处理方法、所涉及的误差改正及数据处理中的一些关键技术;采用直接内插IGS卫星精密星历的方法代替利用IGS跟踪站进行轨道精化方法计算卫星轨道参数,对现有精密单点定位计算方法进行了简化,使之更具有实用性。最后利用自主研发的精密非差单点定位软件计算和分析了实测数据。计算结果表明,经过大约15 min的初始化后,非差相位单历元的定位结果精确度在X,Y,Z方向上均优于20 cm。 相似文献