• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Geodesy >The use of second-generation wavelets to combine a gravimetric quasigeoid model with GPS-levelling data
【24h】

The use of second-generation wavelets to combine a gravimetric quasigeoid model with GPS-levelling data

机译：使用第二代小波将重量拟准模型与GPS水准仪数据相结合

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

The merging of a gravimetric quasigeoid model with GPS-levelling data using second-generation wavelets is considered so as to provide better transformation of GPS ellipsoidal heights to normal heights. Since GPS-levelling data are irregular in the space domain and the classical wavelet transform relies on Fourier theory, which is unable to deal with irregular data sets without prior gridding, the classical wavelet transform is not directly applicable to this problem. Instead, second-generation wavelets and their associated lifting scheme, which do not require regularly spaced data, are used to combine gravimetric quasigeoid models and GPS-levelling data over Norway and Australia, and the results are cross-validated. Cross-validation means that GPS-levelling points not used in the merging are used to assess the results, where one point is omitted from the merging and used to test the merged surface, which is repeated for all points in the dataset. The wavelet-based results are also compared to those from least squares collocation (LSC) merging. This comparison shows that the second-generation wavelet method can be used instead of LSC with similar results, but the assumption of stationarity for LSC is not required in the wavelet method. Specifically, it is not necessary to (somewhat arbitrarily) remove trends from the data before applying the wavelet method, as is the case for LSC. It is also shown that the wavelet method is better at decreasing the maximum and minimum differences between the merged geoid and the cross-validating GPS-levelling data.
机译：考虑使用第二代小波将重力拟准地物模型与GPS水准数据合并，以便将GPS椭球高更好地转换为正常高度。由于GPS水准测量数据在空间域中是不规则的，并且经典的小波变换依赖于傅立叶理论，因此如果不事先进行网格划分就无法处理不规则的数据集，因此经典的小波变换不适用于此问题。取而代之的是，不需要规则间隔数据的第二代小波及其相关的提升方案被用于组合重量准拟地壳模型和挪威和澳大利亚的GPS水准测量数据，并且对结果进行交叉验证。交叉验证是指将合并中未使用的GPS水准测量点用于评估结果，其中合并中会忽略一个点，并用于测试合并后的曲面，对数据集中的所有点都将进行重复。还将基于小波的结果与最小二乘搭配（LSC）合并的结果进行了比较。该比较表明，可以使用第二代小波方法代替LSC，结果相似，但是在小波方法中无需假设LSC的平稳性。具体地说，在应用小波方法之前，不必（任意地）从数据中删除趋势，就像LSC一样。还表明，小波方法在减小合并的大地水准面和交叉验证的GPS水准数据之间的最大和最小差异方面效果更好。

著录项

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