共查询到20条相似文献，搜索用时 343 毫秒
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针对GNSS接收机检定费用较高、检定机构数量少且检定周期长的问题,该文提出了一种简易快速的GNSS接收机检定方法。该方法根据GNSS接收机天线相位中心的几何关系,通过自设简易检定场,利用相对定位法及超短基线法分别检测接收机天线的相位中心偏差和内部噪声水平,并编写了相应的计算程序对检测数据进行快速的处理。4次独立实验结果表明:该文实验方案具有较高的精度和可靠性,适用于快速对GNSS接收机天线相位中心偏差和内部噪声水平进行自检。 相似文献
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GNSS接收机天线相位中心偏差是仪器的一项重要指标,在日常检测、校准过程中往往会遇到相位中心误差超限情况,究竟是仪器本身问题还是测量数据问题？现主要分析GLONASS信号在GNSS接收机天线相位中心检测、校准过程中,由于数据的稳定性对检测、校准结果带来的误差和影响. 相似文献
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魏来 《测绘与空间地理信息》2015,(2):207-208
通过GNSS天线相位中心偏差差值实验,对不同天线类型、不同机构的天线相位中心偏差进行组合,通过对数据比较分析,采用统一机构的天线相位中心偏差参数可有效降低天线相位中心偏差对GNSS点位精度的影响. 相似文献
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在精密定位中,GNSS接收机天线相位中心变化是必须进行改正的影响因素。目前成熟的微波暗室法和自动机器人法,对于一般用户而言,不具备相关实验条件,而野外相对法相对简单、易操作。为此,本文利用相对检测法,对GNSS接收机天线相位中心变化进行检测。实例表明,此方法可获得精度优于±3 mm的检测结果,因此可利用此方法对其他类型天线PCV值进行检测,也可借鉴此方法对北斗接收机天线相位中心变化进行检测。同时论文分析了影响检测精度,提出了有益改进建议。 相似文献
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GPS接收机天线相位中心与其几何中心不重合性构成了GPS接收机天线相位中心误差,如何减少相位中心偏移是天线设计和GPS数据处理中的重要问题。本文在分析GPS接收机天线相位中心在垂直方向上偏差的检测原理的基础上,讨论GPS天线相位中心垂直分量偏差对GPS高程精度的影响,应用实例得出一些有益的结论。 相似文献
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本文介绍了ＧＰＳ接收机使用的各种形式天线，ＧＰＳ接收机的相位中心，以及如何减小相位中心偏差，进一步提高测量精度。 相似文献
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根据多年GPS接收机检验工作实践经验,详细论述了GPS接收机天线相位中心一致性检测方法、原理和具体步骤,并对测地型GPS静态测量和RTK测量精度检测和计算方法、导航型GPS接收机的定位误差检测和计算方法作了阐述。 相似文献
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《International Journal of Digital Earth》2013,6(1):80-87
Abstract Cultures throughout the world are associating with the rivers. People depend upon the rivers and their tributaries for food, water, transport, and many other aspects of their daily lives. Unfortunately, human beings have not calculated the accurate lengths for the great rivers even today. The lengths of the rivers are very different in popular textbooks, magazines, atlases and encyclopedias, etc. To accurately determine the lengths of the principal rivers of the world, the combination of satellite image analysis and field investigations to the source regions is proposed in this paper. The lengths of the Nile, Amazon, Yangtze, Mississippi, Yellow, Ob, Yenisey, Amur, Congo and Mekong, with lengths over or close to 5000 km, were calculated using the proposed method. The results may represent the most reliable and accurate lengths of the principal rivers of the world that are currently achievable. 相似文献
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软科学这一术语是70年代在国外提出的.然而30多年以来,它在国外不仅未得到普遍的承认,而且对软科学的定义也还未能达成大体上一致的共识.而在改革开放后的中国,出于决策科学化和民主化的需要,经过一些领导人的提倡和支持,特别是通过1986年召开的软科学座谈会及1994年召开的全国软科学工作会议,软科学事业得到了蓬勃的发展.据初步统计,截止1998年底全国共有软科学研究机构1224个,研究人员32655人,初步形成了一支较为强大的研究队伍,并取得了数百项覆盖多个领域的研究成果,为支持各级各类的决策发挥了一定的作用. 相似文献
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Tobias Nilsson Benedikt Soja Kyriakos Balidakis Maria Karbon Robert Heinkelmann Zhiguo Deng Harald Schuh 《Journal of Geodesy》2017,91(7):857-866
The very long baseline interferometry (VLBI) Intensive sessions are typically 1-h and single-baseline VLBI sessions, specifically designed to yield low-latency estimates of UT1-UTC. In this work, we investigate what accuracy is obtained from these sessions and how it can be improved. In particular, we study the modeling of the troposphere in the data analysis. The impact of including external information on the zenith wet delays (ZWD) and tropospheric gradients from GPS or numerical weather prediction models is studied. Additionally, we test estimating tropospheric gradients in the data analysis, which is normally not done. To evaluate the results, we compared the UT1-UTC values from the Intensives to those from simultaneous 24-h VLBI session. Furthermore, we calculated length of day (LOD) estimates using the UT1-UTC values from consecutive Intensives and compared these to the LOD estimated by GPS. We find that there is not much benefit in using external ZWD; however, including external information on the gradients improves the agreement with the reference data. If gradients are estimated in the data analysis, and appropriate constraints are applied, the WRMS difference w.r.t. UT1-UTC from 24-h sessions is reduced by 5% and the WRMS difference w.r.t. the LOD from GPS by up to 12%. The best agreement between Intensives and the reference time series is obtained when using both external gradients from GPS and additionally estimating gradients in the data analysis. 相似文献
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In this letter, we are trying to resolve the electromagnetic problem for the movements of the superconducting particles of the protoplanetary cloud in the magnetic field of Saturn. The force of levitation (Meissner-Ochsenfeld phenomenon) is introduced to the field of planetary science for the first time. It is shown from our theoretical analysis that rings of Saturn might have a superconducting origin, and rings might levitate within magnetic equator plane of the planet. 相似文献
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