从GNSS热层延迟中检索折射率场:基于数据的理论和对拼接方法的评估,并与GNSS断层扫描进行比较
Endrit Shehaj1, Alain Geiger1, Markus Rothacher1
1Institute of Geodesy and Photogrammetry, ETH Zürich, Zurich, Switzerland.
Journal of geodesy
|December 3, 2024
概括
最小方形对应为GNSS断层扫描提供了一个强大的替代方案,用于检索折射率场. 这种方法对先前数据的依赖性较低,并有效地捕捉大气变化,特别是在改进的网络分辨率和站点分布的情况下.
科学领域:
- 大气科学 大气科学
- 地质测量是指地质测量.
- 信号处理 信号处理
背景情况:
- 从全球导航卫星系统 (GNSS) 测量中检索大气折射率对于各种应用至关重要.
- 像GNSS断层扫描这样的传统方法通常依赖于网格数据和先验信息.
- 最小正方形拼接为估计折射率场提供了一个无网格的方法.
研究的目的:
- 评估最小正方形聚合用于折射率检索的能力和局限性.
- 为了比较同位素与GNSS断层扫描,突出优缺点.
- 调查网络配置对拼接性能的影响.
主要方法:
- 对于有关延迟和折射率的参数估计,最小二次方位对应调整.
- 在 colocation 中分析功能和随机模型.
- 拼接和断层扫描之间的理论错误的比较.
- 使用真实和模拟的GNSS数据调查站分辨率和高度效应.
- 使用COSMO天气模型数据和闭环模拟进行验证.
- 检测接近的天气阵线的应用程序.
主要成果:
- 与断层扫描相比,拼接表现出形式变异/共变的变化较小,并且对先验字段的依赖较小.
- 增加网络分辨率 (例如2公里) 可以改善后期统计数据,将折射率误差降低10%至6公里.
- 较高的站点高度改善了折射率场,将标准偏差降低了1ppm,偏差降低了3ppm,达到3公里.
- 拼接有效地捕捉了高度水平内的相对折射率变化,而断层扫描则产生了较少偏差的估计.
- 这两种方法都检测到天气前线,在分布良好的GNSS高度覆盖下观察到更相似的大气结构.
结论:
- 最小方形对应是GNSS断层扫描的有价值的替代方案,用于反射率场的检索.
- 网络设计,包括站点密度和高度,显著影响检索折射率的准确性.
- 配电的无电网性质和减少对事先信息的依赖提供了明显的优势.
- 需要进一步研究合并的最佳网络配置.
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