共查询到18条相似文献,搜索用时 62 毫秒
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目的 从利用GPS提取区域电离层总电子含量(total electron content,TEC)的基本原理出发,解决了伪距观测值优化以及硬件延迟(DCB)处理问题,并将提取的TEC信息与欧洲定轨中心(CODE)计算的全球电离层(GIM)模型内插值应用在单频精密单点定位中,进行电离层延迟改正实验。结果表明,利用本文提取的TEC值进行单频精密单点定位电(PPP)离层延迟改正时,点位精度能提高到0.2~0.4m左右,明显优于利用GIM内插值的改正精度。 相似文献
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电离层参量的提取是开展电离层研究的基础,而数据同化技术则是获取电离层参量的一种重要手段。以NeQuick模型的输出作为背景场,Kalman滤波作为同化算法,利用数据同化技术实现区域电离层TEC重构,结果表明,数据同化方法重构的倾斜总电子含量(TEC)和垂直TEC与实测值较为一致。相比NeQuick模型及全球电离层地图(GIM)数据,数据同化方法重构得到的TEC的平均误差和标准差均有明显的降低,实测数据验证了数据同化技术在区域TEC重构中的精度和可靠性。 相似文献
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为了分析与评估国际GNSS监测评估系统(iGMAS)全球电离层TEC格网产品精度,该文基于iGMAS及IGS各电离层分析中心发布的全球电离层TEC格网产品,进行了精度比较分析,结果表明:iGMAS与IGS、CODE、JPL、ESOC、UPC等IGS电离层工作组发布的全球电离层TEC格网产品,在全球、不同纬度带和欧洲等不同区域均表现出较高的一致性和强相关性,互差为0~2.0 TECU;JPL分析中心GIM的内符合精度约为2.5 TECU,iGMAS、IGS、CODE、ESOC和UPC等分析中心GIM的内符合精度均小于1.5 TECU;在2~8 TECU的精度范围内,iGMAS全球电离层TEC格网产品的精度总体与IGS、CODE、JPL、ESOC、UPC等IGS电离层工作组的精度相当。 相似文献
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GAMIT/GLOBK是全球应用最广泛的高精度GPS数据处理软件之一,不仅在高精度定位方面得到应用,而且在全球地壳板块运动监测、电离层监测和GPS气象学等领域也得到广泛应用。本文介绍了在Windows7系统下实现Ubunru Kylin16.04桌面版系统的安装,并在Ubuntu Kylin系统平台下安装、更新最新版GAMIT/GLOBK10.60,并利用中国及其周边IGS站观测数据进行基线解算和网平差,验证了软件安装的正确性。 相似文献
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Linux系统由于其开放性、安全性和稳定性受到众多机构和科研单位的认可,许多知名的卫星导航定位软件都是基于Linux系统开发。Shell脚本语言是Linux系统上一种重要的脚本语言,熟练地使用Shell语言可以解决或简化许多问题。本文总结了Shell语言在卫星定轨软件中的一些应用,包括数据下载、数据合并、数据传输、自动化运行与错误预警等,可以为从事卫星导航定位领域的科研人员或工作人员提供参考。 相似文献
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本文在研究了目前存在方法的基础上,将数理统计中的方差分析周期叠加外推法应用于电离层短期预报,并对其作了改进。采用IGS提供的电离层TEC数据作为原始数据比较了该方法改进前后的预报精度,分别利用中国区域内不同地理位置的40天的数据进行分析预报,预报结果显示改进后的方法预报精度可达到1.1TECU左右,优于改进前。改进后的预报效果依然与经纬度有关,在中国区域内随着纬度的减小、经度的增加,预报精度会降低。通过与目前常用方法比较分析,该方法预报结果精度较高、所需计算参数少、简单易行,可以较好地应用于电离层短期预报。 相似文献
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针对不同电离层产品精度存在差异的问题,对国际全球卫星导航系统(GNSS)服务员组织(IGS)、美国喷汽动力实验室(JPL)、欧洲定轨中心(CODE)、国际GNSS监测评估系统(iGMAS)、欧空局欧洲空间运行中心(ESOC)分析中心电离层产品进行精度评估,实验结果表明:在中国地区CODE和ESOG的中心电离层产品电离层格网数据(GIM)时间序列结果表现出高度的一致性;在欧洲地区CODE、ESOG和IGS中心电离层产品GIM的时间序列结果表现出高度的一致性;JPL中心电离层产品在中国地区、欧洲地区VTEC日平均值均最大;iGMAS中心电离层产品在中国地区、欧洲地区电离层VTEC日平均值均最小。IGS、JPL、CODE、i GMAS、ESOC分析中心电离层产品在中国地区VTEC的互差在3.6 TECU内,在欧洲地区VTEC的互差在3.2 TECU内,IGS、JPL、CODE、iGMAS、ESOC分析中心电离层产品在中国地区VTEC值相关系数均大于0.90,在欧洲地区相关系数均大于0.94,均表现出强相关性。 相似文献
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The ionospheric shell height has an impact on the estimated differential code bias (DCB) and total electron content (TEC) obtained by global navigation satellite system (GNSS) data, especially for a single site. However, the shell height is generally considered as a fixed value. Based on data from the international GNSS service (IGS), we propose the concept of optimal ionospheric shell height, which minimizes |ΔDCB| when compared to the DCB provided by Center for Orbit Determination in Europe (CODE). Based on the data from five IGS stations at high, middle, and low latitudes during the time 2003–2013, we investigate the variation in the optimal ionospheric shell height and its relation with the solar activity. Results indicate that the relation between the mean of the optimal ionospheric shell height and the latitude is N-shaped. At the three stations at midlatitude, the mean value almost increases linearly with the latitude. The optimal ionospheric shell heights show 11-year and 1-year periods. The influences of the solar activity are related to the means of the optimal ionospheric shell height during the time 2003–2013. The slope of the linear fitting decreases with the mean value. Using the data from 2003 to 2013, we estimate the daily optimal ionospheric shell heights for 2014 by using the Fourier fitting method and then calculate the daily average of ΔDCB of the observed satellites by comparing to CODE results. The statistical results of the daily average in 2014 show that the optimal ionospheric shell height is much better than the fixed one. From the high-latitude station to the low-latitude station, the improvements in the mean value are about 75, 92, 96, 50, and 88% and the root-mean-squares are reduced by about 0.16, 2.09, 2.01, 1.01, and 0.02 TECu, respectively. 相似文献
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She Chengli Wan Weixing Yue Xinan Xiong Bo Yu You Ding Feng Zhao Biqiang 《GPS Solutions》2017,21(3):1125-1137
GPS Solutions - We developed a parameterized ionospheric electron density model based on the IRI-2012 model by spherical harmonic expansions in the horizontal and empirical orthogonal functions in... 相似文献
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针对太阳活动影响电离层变化的问题,该文利用2000年到2020年太阳黑子数和IGS组织提供的全球电离层总电子含量(TEC)格网数据,借助数理统计、相关系数及时间序列等方法,研究了太阳黑子数与电离层TEC之间的关系.实验结果表明:①两者之间的相关性具有分段变化的性质,分段变化由太阳黑子数的临界点L决定,因此确定了太阳黑子数与TEC日均值相关性的分段函数,并给出了太阳黑子数临界点L;②太阳黑子数的变化会引起电离层TEC值的变化,而这个变化具有1~3 d的滞后性,其中电离层TEC日均值滞后于太阳黑子数2d最为明显;③太阳黑子数和电离层TEC值具有明显的相关性,但太阳黑子数与电离层TEC值之间年相关性强弱不均. 相似文献
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Performance of various predicted GNSS global ionospheric maps relative to GPS and JASON TEC data 总被引:2,自引:0,他引:2
When using predicted total electron content (TEC) products to generate preliminary real-time global ionospheric maps (GIMs), validation of these ionospheric predicted products is essential. In this study, we evaluate the accuracy of five predicted GIMs, provided by the international GNSS service (IGS), over continental and oceanic regions during the period from September 2009 to September 2015. Over continental regions, the GPS TEC data collected from 41 IGS continuous tracking stations are used as a reference data set. Over oceanic regions, the TEC data from the JASON altimeter are used for comparison. An initial performance comparison between the IGS combined final GIM product and the predicted GIMs is also included in this study. The evaluation results show that the predicted GIMs produced by CODE outperform the other predicted GIMs for all three validation results. The accuracy of the 1-day predicted GIMs, produced by the IGS associate analysis centers (IAACs), is higher than that of the 2-day predicted GIMs. Compared to the 2-day UPC predicted GIMs, the 2-day ESA predicted GIMs are observed to have slightly worse performances over ocean regions and better positioning performances over continental regions. 相似文献
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The inverse distance weighted model (IDWM) represents a geo-spatial interpolation technique used for estimation of ionospheric
vertical delays at the ionospheric grid points (IGPs) and user ionospheric pierce points (IPPs). The GPS Aided Geo Augmented
Navigation (GAGAN) system is planned for air-navigation over the Indian service region using a space based augmentation. One
of the main needs for GAGAN is to develop a suitable grid-based ionospheric model for estimating the vertical delay and its
error bound, i.e., grid ionospheric vertical error (GIVE) at all the IGPs covering the Indian subcontinent. Dual frequency
GPS receiver data obtained from 17 total electron content (TEC) stations are considered in the analysis. For a typical IGP
(25°N, 75°E), variations in the GIVE for a few days of quiet ionosphere are presented. For a quiet and magnetically moderate
day, the mean and standard deviations of the user IPP (UIPP) estimation error and the mean GIVE are presented using the IDWM
with Klobuchar, Junkins and bilinear models. 相似文献
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Evaluation of COMPASS ionospheric grid 总被引:1,自引:0,他引:1
As an important component of the augmentation service, the ionospheric grid contributes to improving single-frequency positioning accuracy. The ionospheric delay corrections are broadcast as vertical delay estimates at specified ionospheric grid points (IGPs) for most satellite-based augmentation system, where the IGPs are predefined with a resolution of 5° and 5° in latitude and longitude. Different from the general strategy, the COMPASS IGPs are predefined with a resolution of 2.5° and 5° in latitude and longitude. The need for this special IGPs distribution is investigated with experiments using real data. The performance of the COMPASS ionospheric grid is analyzed in terms of accuracy and availability. Comparing the performance of the special IGPs distribution with that of 5° × 5° IGPs, the results show that the ionospheric correction improves by 0.2 m and the 3D positioning accuracy improves by 1 m in middle-low latitude regions. The RMS of the COMPASS grid ionospheric correction accuracy is better than 0.5 m in most regions of the China mainland, and the availability is better than 95 % except in the northeast, northwest and outside China. In addition, we investigated the performance of the method that combined the inverse distance weighted and spherical harmonics grid modeling algorithm. Simulations show that the new method clearly improves grid availability. The mean availability in the mainland is better than 99 %. 相似文献