一种基于边缘计算的RTK定位方法

实时动态载波相位差分(Real-Time kinematic,RTK)定位是一种基于载波相位观测值的实时动态定位技术,通过架设基准站并将基准站数据与流动站数据进行差分解算获取流动站的精确位置,从而得到比传统GPS定位更为精确的结果。本文提出了一种基于边缘计算的实时动态载波相位差分定位方法 E-RTK(Edge Real-Time Kinematic),通过将RTK解算任务迁移至边缘设备,降低RTK移动端对硬件的算力需求,进而降低RTK定位的硬件成本。本文基于E-RTK进行了实现及测试,实验证明,该E-RTK定位在较低的硬件成本下,能够达到与传统RTK定位相当的精度,除此之外,在使用GPS+BEIDOU卫星数据进行解算定位时,相较于常见的GPS+GLONASS定位,其Fix速度具有较大提升。     

多参考站网络的虚拟观测值生成算法

讨论了GPS观测值误差改正方法,提出了一种基于多参考站的GPS观测值向流动站用户发布虚拟观测值的算法.该算法通过参考站的已知精确坐标和已经解算的模糊度计算参考站间双差空间相关误差,然后内插局域网内任意一点空间相关误差作为改正数.当只使用3个参考站时使用线性内插法,多于3个参考站时使用曲面拟合或最小二乘平差方法等内插方法.用内插获得的改正数改正离流动站最近的参考站(主参考站)的观测值,形成虚拟观测值,然后发送给流动站用户,流动站用户仍然应用已有的单参考站GPS定位算法进行定位.通过对江苏局域参考站网络收集的实测数据计算分析证明了本文算法的有效性,达到厘米级定位精度.     

基于GPS技术的铁路既有线中线测量研究

结合改建线路襄渝线工程,采用GPS静态定位进行控制测量,并在此基础上研究采用GPS-RTK技术进行线路中线测量.实践表明,这种作业方法可以省掉许多不必要的中间环节,最大限度地减少外业工作量,从而使整个勘测工期达到最短.     

Reference station network based RTK systems-concepts and progress

The limitation of single base "real-time kinematic"(RTK) techniques is the distance between base receiver and the rover receiver due to distance-dependent biases, namely orbit bias,ionosphere bias and troposphere bias. Techniques have been developed to overcome this distance dependence using a network of GPS reference stations spread over a wide geographic area. Because the measurement biases will be modelled and corrected for, the positioning accuracy will be almost independent of the inter-receiver distance.Since the mid-1990s investigators have been investigating the optimal means of processing reference receiver data, and then providing generally referred to as Network-RTK. In 1993 the International Association of Geodesy (IAG) established a Special Study Group on"Wide Area Modelling for Precise Satellite Positioning" . This paperfocusses on the progress made during the last few years in designing Network-RTK architectures and the associated data processing algorithms and issues. Although many university investigators have been researching the fundamental challenges in functional and stochastic modelling, currently there is only one commercially available Network-RTK product, the Trimble VRS. However, with the use of the Internet as the primary data communication link, it is predicted that various sites around the world, over the next few years.     

基于车载GPS定位误差分布规律的地图匹配算法

针对目前车载GPS定位信息地图匹配技术的主要缺陷,即GPS定位点的道路纵向位置修正效果较差,特别是对GPS独立定位的情况而言,修正精度很低,通过分析车载GPS定位误差的特点及其分布规律设计了一种地图匹配算法,重点提高车载GPS定位点在道路纵向的修正精度.采用长春市局部路网的地理信息为基础,采集车载GPS实测数据完成了算法的实证分析.结果表明,所提出的地图匹配算法应用效果理想,尤其是将车载GPS定位点的道路纵向位置修正精度提高了2.5 m以上,从而可满足车载GPS数据用户更高水平的信息需求.     

GPS网络RTK误差改正数生成算法精度分析

分析了GPS网络RTK系统的误差改正数生成算法的现状,通过模拟网络RTK区域网,采用不同的算法和网形进行试验,计算了误差改正数的内插质量因子,并进行了分析、比较。结果表明,各种算法在计算内插流动站误差时是有效的,其中线性组合法和线性内插法可获得较优结果,同时证明了流动站在网络中的位置和所选基准站网形的不同对算法模型的计算精度有较大影响。     

一种全球导航卫生系统钟差估计优化方案的量化研究

摘要：针对卫星钟差解算策略的优化问题，本文基于BERNESE GNSS数据处理软件，设计了卫星估计钟差解算方案。提出了“单位时间误差梯度”的概念，量化了解算精密钟差的效率。采用基于TIN的选站法选取参考站，利用历元参数在历元间的独立性，分步解算各类参数。既减少了因大量历元参数存在引起的时间迟滞，又消除了单历元观测离群值对非历元参数估计的影响，从而提高了GNSS卫星钟差估计效率。利用IGS跟踪站作为参考站对以上解算过程进行实验，结果表明估计钟差与IGS精密钟差的符合精度达到0.1ns，陆态网精密单点定位（PPP）动态解最大偏差小于10cm，能够满足动态定位厘米级的精度要求，为估计钟差时参考站的数量和几何分布的选择提供了参考。     

Using quasi ionosphere-free post-processing algorithm on the medium-range kinematic high accuracy GPS relative positioning

We utilize Quasi Ionosphere-Free (QIF) post-processing algorithm to account for ionosphere delay and use addition parameters to solve for tropospheric bias. Then the estimated integer ambiguities and troposphere parameters are fixed to acquire kinematic relative positions at every epoch.Using kinematic relative positioning, data from the Taiwan continuous GPS network (TCGN) are utilized to analyze the co-seismic displacements associated with the 21 September 1999 Chi-Chi earthquake (ML=7.3). The station near the highest peak of Taiwan, Yushan (YUSN) and a station ineastem Taiwan, Fenglin (FLNM) show significant co-seismic displacements of 18 and 12 cm in the north direction as well as 16 and 24 cm in the west direction, respectively. Comparing the co-seismic displacements estimated from daily solutions with those from kinematic results, the differences are less than 2 cm in the horizontal components. The impact of the major aftershocks occurred immediately after the mainshock can be identified from the kinematic positioning. The same algorithm is also applied to study the 1 Hz sampling rate data related to 31 March 2002 off Hualien earthquake (ML=6.8), seven stations of the TCGN are analyzed to study the co-seismic deformation. With the higher sampling rate data, the instantaneous ground motion caused by the propagation of seismic waves can be observed.     

VRS技术在建筑红线定位测量中的应用

VRS(虚拟参考站)技术是GPS(全球定位系统)网络RTK(实时动态定位)技术的一种,它与传统测量技术和传统RTK技术相比有很多优点。文中结合武汉市建筑红线定位测量的实践,探讨了VRS技术在建筑红线定位测量中应用的控制加密、实地放线等问题。实践应用分析证明,利用VRS技术不仅能提高精度,保证工作的质量,还能大幅提高工作效率。     

矿山变形监测中常规RTK精度提高方法研究

矿山变形监测是矿山安全开采与可持续发展的重要组成部分.基于GPS RTK技术,利用实地采集的观测数据,以静态相对定位结果作为参考,分析对中杆倾斜量对于RTK流动站水平和垂直点位精度的影响.研究结果表明,对中杆倾斜误差对RTK水平定位精度影响较大,但对垂直误差影响很小;采用三脚架模式,可获得毫米级的平面定位精度;而高程精度与点间高差相关性较大,只能达到厘米级的精度.