共查询到20条相似文献，搜索用时 46 毫秒
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高性能原子钟钟差建模及其在精密单点定位中的应用 总被引：2，自引：2，他引：0
鉴于当前许多IGS跟踪站均配置有高性能原子钟的现状,本文首先采用修正Allan方差法分析了不同IGS跟踪站的接收机钟随机噪声的时域特性,进而评估了不同类型接收机的短期稳定度及钟差建模的可行性,然后利用IGS站配有氢原子钟的观测数据,在精密单点定位算法中,通过对钟差参数进行短时建模约束接收机钟差的随机变化,进而改进精密单点定位(PPP)的定位性能。试验结果表明钟差建模方法显著降低了高程分量参数、天顶对流层延迟参数与接收机钟差参数之间的相关性,GNSS高程分量的精度可提高50%。该方法对于提升PPP技术在地壳形变监测、低轨卫星定轨、水汽监测及预报等高精度GNSS地学领域的应用水平具有一定意义。 相似文献
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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
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讨论了基于精密单点定位技术来实现无已知控制点的海岛礁平面控制测量,分别从观测数据时段长度和数据采样间隔两个方面分析精密单点定位的静态解算精度及收敛情况,计算结果表明,IGS跟踪站的PPP(Precise Point Positioning)单天解在平面方向的精度为mm级,高程方向的精度为2~3cm;同时,还得出了PPP技术应用于静态控制测量的采样率以及静态解的收敛时间。最后用静态数据精密单点定位的结果同Gamit网解求较差计算出两者之差值。试验证明,静态精密单点定位技术能够用于高精度海岛礁平面控制测量。 相似文献
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GPS非差相位精密单点定位技术探讨 总被引：77，自引：12，他引：77
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15min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20cm。 相似文献
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对基于历元间差分相位和非差伪距观测值的混合差分卫星钟差估计方法进行了改进,实现了多模全球导航卫星系统（Global Navigation Satellite System,GNSS）卫星钟差联合快速估计。选择了全球分布的50个跟踪站进行实验,对卫星钟差精度进行了分析和精密单点定位（Precise Point Positioning,PPP）验证。结果表明:多模卫星钟差与武汉大学提供的最终精密卫星钟差互差优于0.2 ns,精密单点定位结果与武汉大学发布的最终精密卫星轨道和钟差产品的定位精度相当。 相似文献
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随着IGS星历产品的种类和精度不断提高,精密单点定位对星历有了更多的选择。本文对IGS星历和广播星历进行了精度对比,同时介绍了相位平滑伪距的原理,着重通过对伪距单点定位和相位平滑伪距单点定位与广播星历I、GU星历和IGS最终星历的组合对国内IGS跟踪站(shao)进行单点定位的分析,证明了伪距平滑后的定位精度有了明显的提高,使用IGU星历比广播星历定位精度也有所提高。 相似文献
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采用Landsat TM数据分析了阿克苏河—塔里木河断面水质污染状况,通过波段的DN值和常规监测数据建立能反映水质状况的
污染物监测模型。结果发现,将2000年常规监测数据代入模型后,与遥感数据的结果基本吻合| 重建阿克苏河—塔里木河的连续水体
污染变化曲线,得出污染物浓度随着远离上游而增加。 相似文献
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Piyoosh Rautela Ramesh Chandra Lakhera 《International Journal of Applied Earth Observation and Geoinformation》2000,2(3-4)
The area around Sataun in the Sirmur district of Himachal Pradesh, India (falling between the rivers Giri and Tons; both tributaries of the Yamuna River) was studied for landslide vulnerability on behalf of the inhabitants. The study was made using extensive remote sensing data (satellite and airborne). It is well supported by field evidence, demographic and infrastructural details and aided by Geographic Information System (GIS) based techniques. Field observations testify that slope, aspect, geology, tectonic planes, drainage, and land use all influence landslides in the region. These parameters were taken into consideration using the statistical approach of landslide hazard zonation. Using the census data of 1991, vulnerability of the populace to the landslide hazard was accessed. As most of the infrastructure in the region is concentrated around population centres, population data alone was used for vulnerability studies. 相似文献
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ZHAN F. Benjamin 《地球空间信息科学学报》2011,(1)
Although it is well known that coseismic gravity changes take place during an earthquake, previous research has not yielded convincing evidence demonstrating that significant gravity changes occur before large earthquakes. Furthermore, even if we suspect that gravity changes occur before large earthquakes, we have yet to demonstrate how to consistently observe these changes for useful earthquake forecast that would bring benefits to society. We analyzed ground gravity survey data obtained in 1998, 2000, 200... 相似文献
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GNSS系统及其技术的发展研究 总被引：3，自引：1，他引：2
阐述了国际上卫星导航系统的总体发展,对美、俄、欧、中的四大全球系统,以及相关的区域系统和增强系统进行了简单的介绍,研究分析了GNSS系统及其技术的发展趋势,同时分析了我国Compass全球系统面临的机遇和挑战,并提出了我国未来工作的建议. 相似文献
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“4D”技术及其应用 总被引：13，自引：0，他引：13
介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。 相似文献
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《International Journal of Digital Earth》2013,6(1):66-87
Abstract Virtual Australia is not a well-defined or agreed concept. This discussion paper conceptualises Virtual Australia as a ‘virtual [digital] model containing and representing all non-trivial objects and their contextual environment – from blue sky to bedrock – in real world Australia’. It describes a scenario for Virtual Australia, one or two decades from now, in which the locations and conditions of non-trivial objects and their environment are updated automatically through a combination of remote sensing and wireless communication technologies in support of a ‘Supranet’. It then examines the concept of the ‘Supranet’ – a pervasive information network based largely on wireless technology linking the physical world to a virtual model in real time – and develops and discusses three principal characteristics of the Supranet: the ability to have or collect specific information (know); the ability to process information (think); and the ability to communicate that information. If, in the near future, any or all non-trivial devices are to some extent able to know, think and communicate, the potential for object autonomy will be realised. 相似文献
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Toward seamless indoor-outdoor applications: Developing stakeholder-oriented location-based services
Kohei OGAWA Edward VERBREE Sisi ZLATANOVA Naohiko KOHTAKE Yoshiaki OHKAMI 《地球空间信息科学学报》2011,14(2):109-118
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders. 相似文献