An Improved Tomography Approach Based on Adaptive Smoothing and Ground Meteorological Observations
Abstract
:1. Introduction
2. The GNSS Network and Data Analysis
2.1. The Hong Kong SatRef Network
2.2. Data Analysis
3. Tomography Approach
3.1. General Methods and Existing Problems
3.2. Improved Tomography Algorithm
3.2.1. Laplacian Smoothing
3.2.2. Helmert Variance Component Estimation
3.2.3. The Adaptive Laplacian Smoothing Approach
3.3. Comparisons Between Adaptive Smoothing and Constant Smoothing
4. Validation of the New Tomography Algorithm
4.1. Comparison with Radiosonde Data
4.2. Comparison with ECMWF Data
5. Discussion
6. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
References
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A Priori Data | Rainy Period | Rainless Period | |||||
---|---|---|---|---|---|---|---|
Bias | STD | RMSE | Bias | STD | RMSE | ||
Low (<5.6 km) | No | −4.9 | 12.6 | 13.8 | −3.2 | 13.0 | 13.6 |
Lowest radiosonde observation | −1.8 | 5.5 | 6.6 | 0.3 | 7.9 | 8.2 | |
GNSS meteorological data | −1.6 | 7.2 | 8.4 | 0.9 | 9.0 | 9.4 | |
Total | No | −2.5 | 10.0 | 10.5 | −0.8 | 10.2 | 10.3 |
Lowest radiosonde observation | −1.9 | 4.9 | 5.7 | −0.6 | 6.2 | 6.4 | |
GNSS meteorological data | −2.3 | 5.9 | 6.8 | −0.6 | 7.2 | 7.3 |
A Priori Data | Rainy Period | Rainless Period | |||||
---|---|---|---|---|---|---|---|
Bias | STD | RMSE | Bias | STD | RMSE | ||
Low (<5.6 km) | No | −1.7 | 10.5 | 10.7 | −2.2 | 11.6 | 12.1 |
Lowest radiosonde observation | −1.3 | 6.5 | 7.1 | −0.2 | 7.7 | 8.3 | |
GNSS meteorological data | −0.9 | 6.9 | 7.3 | 0.4 | 7.8 | 8.4 | |
Total | No | −0.7 | 7.9 | 8.1 | −0.5 | 8.9 | 9.0 |
Lowest radiosonde observation | −1.7 | 5.3 | 5.7 | −1.3 | 6.2 | 6.5 | |
GNSS meteorological data | −2.1 | 5.4 | 6.0 | −1.4 | 6.4 | 6.8 |
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Zhang, B.; Fan, Q.; Yao, Y.; Xu, C.; Li, X. An Improved Tomography Approach Based on Adaptive Smoothing and Ground Meteorological Observations. Remote Sens. 2017, 9, 886. https://doi.org/10.3390/rs9090886
Zhang B, Fan Q, Yao Y, Xu C, Li X. An Improved Tomography Approach Based on Adaptive Smoothing and Ground Meteorological Observations. Remote Sensing. 2017; 9(9):886. https://doi.org/10.3390/rs9090886
Chicago/Turabian StyleZhang, Bao, Qingbiao Fan, Yibin Yao, Caijun Xu, and Xingxing Li. 2017. "An Improved Tomography Approach Based on Adaptive Smoothing and Ground Meteorological Observations" Remote Sensing 9, no. 9: 886. https://doi.org/10.3390/rs9090886