• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Second-order ionospheric effects on satellite radio occultation observations and their impact on atmospheric studies.
【24h】

Second-order ionospheric effects on satellite radio occultation observations and their impact on atmospheric studies.

机译：电离层对卫星无线电掩星观测的二阶效应及其对大气研究的影响。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This dissertation describes the development of first-of-a-kind mathematical models that both quantify higher-order ionospheric effects and their impact on Global Positioning System radio occultation (GPS/RO) data products. We develop new and innovative models to: a) remove the second-order ionospheric effect from Total Electron Content (TEC) estimations; b) quantify the second-order ionospheric delay in GPS/RO signal propagation using the Faraday phenomenon; c) quantify the vertical distribution of the first- and second-order ionospheric residual effects on GPS/RO data products; and d) retrieve improved atmospheric water vapour profiles. For the first time we combine GPS/RO measurements with space-based gravity missions to characterize the response of the GPS/RO-derived atmospheric parameters to the Earth's gravity anomalies.;the water vapour pressure. Further studies reveal that the second-order ionospheric residual effect increases non-linearly with solar variability, oscillating between +/-3 mm (at Rz12=2) and +/-15 mm (at Rz12=114), whereas its value increases with increasing latitude. The first-order ionospheric residual effect arising from the geometrical splitting of the dual-frequency GPS radiowave signals is ∼2-3 orders of magnitude smaller than the second-order ionospheric residual effect, with the potential of increasing in magnitude at high solar activity. A series of sensitivity studies show that the LEO velocity uncertainties affect the GPS/RO bending angle accuracy more than the Doppler shift uncertainties. Finally, we find that the Earth's gravity anomalies can introduce negative systematic biases on the atmospheric temperature profiles of up to ∼0.5 K close to the Earth's surface. This dissertation demonstrates the simplicity, innovation, effectiveness and importance of our proposed mathematical models on the future of GPS/RO atmospheric remote sensing.;Independently, we implement these mathematical models in a new GPS/RO processing software package to investigate, for the first time, the impact of higher-order ionospheric residual effects on ionospheric and atmospheric products. We observe that under low solar activity, the second-order ionospheric residual effect introduces: a) slowly varying positive systematic biases of ∼1-3 TECU on TEC estimations as function of occultation time; b) maximum negative systematic biases of ∼0.35 N-units on atmospheric refractivity close to the Earth's surface; c) negative systematic biases of ∼0.5 K close to the Earth's surface, which decrease with altitude and above 26 km become positive, peaking at ∼2.0 K at 50 km and d) negative systematic biases of ∼0.08 mbar on
机译：这篇论文描述了第一个数学模型的发展，该数学模型可以量化高阶电离层效应及其对全球定位系统无线电掩星（GPS / RO）数据产品的影响。我们开发了新的创新模型，以：a）从总电子含量（TEC）估计中消除二阶电离层效应； b）利用法拉第现象量化GPS / RO信号传播中的二阶电离层延迟； c）量化一阶和二阶电离层残余效应对GPS / RO数据产品的垂直分布； d）获得改善的大气水蒸气剖面。我们首次将GPS / RO测量值与天基重力任务相结合，以表征GPS / RO衍生的大气参数对地球重力异常的响应。进一步的研究表明，二阶电离层残余效应随太阳变化而非线性增加，在+/- 3 mm（在Rz12 = 2时）和+/- 15 mm（在Rz12 = 114时）之间振荡，而其值随纬度增加。双频GPS无线电波信号的几何分裂所产生的一阶电离层残留效应比二阶电离层残留效应小2-3个数量级，并且在高太阳活动时其势能会增加。一系列敏感性研究表明，LEO速度不确定性对GPS / RO弯曲角精度的影响大于多普勒频移不确定性。最后，我们发现地球重力异常会在接近地球表面的最高约0.5 K的大气温度剖面上产生负的系统偏差。本文论证了我们提出的数学模型对GPS / RO大气遥感的未来的简单性，创新性，有效性和重要性。;我们将在新的GPS / RO处理软件包中独立实现这些数学模型，以进行首次研究。时间，高阶电离层残余效应对电离层和大气产物的影响。我们观察到在低太阳活动下，二阶电离层残余效应会引入：a）慢慢地改变1-3 TECU对TEC估计值的正系统偏差作为掩星时间的函数； b）在接近地球表面的大气折射率上的最大负系统偏置量约为0.35 N个单位； c）靠近地球表面的〜0.5 K的负系统偏差，随着高度的增加而减小，在26 km以上时变为正值，在50 km时达到约2.0 K的峰值，并且d）在系统上约0.08 mbar的负系统偏差。

著录项

  • 作者

    Vergados, Panagiotis.;

  • 作者单位

    York University (Canada).;

  • 授予单位 York University (Canada).;
  • 学科 Physics Astronomy and Astrophysics.
  • 学位 Ph.D.
  • 年度 2011
  • 页码 176 p.
  • 总页数 176
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号