Articles | Volume 36, issue 4 
            
                
                    
                    
                        
            
            
            https://doi.org/10.5194/angeo-36-1037-2018
                    © Author(s) 2018. This work is distributed under 
the Creative Commons Attribution 4.0 License.
                the Creative Commons Attribution 4.0 License.
Special issue:
                        
                    https://doi.org/10.5194/angeo-36-1037-2018
                    © Author(s) 2018. This work is distributed under 
the Creative Commons Attribution 4.0 License.
                the Creative Commons Attribution 4.0 License.
An optimal tropospheric tomography approach with the support of an auxiliary area
Qingzhi Zhao
CORRESPONDING AUTHOR
                                            
                                    
                                            College of Geomatics, Xi'an University of Science and Technology,
Xi'an, China
                                        
                                    Yibin Yao
                                            School of Geodesy and Geomatics, Wuhan University,
Wuhan, China
                                        
                                    
                                            Key Laboratory of Geospace Environment and Geodesy,
Ministry of Education, Wuhan University, Wuhan, China
                                        
                                    Wanqiang Yao
                                            College of Geomatics, Xi'an University of Science and Technology,
Xi'an, China
                                        
                                    Pengfei Xia
                                            GNSS
Research Centre, Wuhan University, Wuhan,
China
                                        
                                    Related authors
Wanqiang Yao, Haoran Huang, Xiongwei Ma, Qi Zhang, Yibin Yao, Xiaohu Lin, Qingzhi Zhao, and Yunzheng Huang
                                    Ann. Geophys., 42, 455–472, https://doi.org/10.5194/angeo-42-455-2024, https://doi.org/10.5194/angeo-42-455-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                There is limited discourse on the influence of the different analysis-center-based state-space representation (SSR) corrections on the accuracy of real-time zenith tropospheric delay (RT ZTD). Our primary objective is to compare the real-time precise point positioning (RT-PPP) performance and RT-PPP-derived ZTD accuracy and availability based on different SSR products. The findings serve as a valuable reference for selecting SSR products in RT-PPP-derived ZTD.
                                            
                                            
                                        Yibin Yao, Linyang Xin, and Qingzhi Zhao
                                    Ann. Geophys., 37, 89–100, https://doi.org/10.5194/angeo-37-89-2019, https://doi.org/10.5194/angeo-37-89-2019, 2019
                                    Short summary
                                    Short summary
                                            
                                                In this paper, we propose an improved pixel-based water vapor tomography model, which uses layered optimal polynomial functions by adaptive training for water vapor retrieval. Under different scenarios, tomography results show that the new model outperforms the traditional one by reducing the root-mean-square error (RMSE), and this improvement is more pronounced, at 5.88 % in voxels without the penetration of GNSS rays. The improved model also has advantages in more convenient expression.
                                            
                                            
                                        Qingzhi Zhao, Kefei Zhang, and Wanqiang Yao
                                    Ann. Geophys., 37, 15–24, https://doi.org/10.5194/angeo-37-15-2019, https://doi.org/10.5194/angeo-37-15-2019, 2019
                            Qingzhi Zhao, Yibin Yao, and Wanqiang Yao
                                        Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-76, https://doi.org/10.5194/angeo-2018-76, 2018
                                    Manuscript not accepted for further review 
                                    Short summary
                                    Short summary
                                            
                                                This paper captures the signature of heavy rainfall events using the 2-d-/4-d water vapour information derived from GNSS measurement in Hong Kong. The paper first analyzed the relationship between the two-dimensional (2-d) precipitable water vapour (PWV) and rainfall. And then, the four-dimensional (4-d) variations of atmospheric water vapour derived from the GNSS tomographic technique  are discussed, especially in the vertical irection. Finally, some interesting results are found and presented.
                                            
                                            
                                        Qingzhi Zhao, Yibin Yao, and Wanqiang Yao
                                    Ann. Geophys., 35, 1327–1340, https://doi.org/10.5194/angeo-35-1327-2017, https://doi.org/10.5194/angeo-35-1327-2017, 2017
                            Qingzhi Zhao and Yibin Yao
                                    Ann. Geophys., 35, 87–95, https://doi.org/10.5194/angeo-35-87-2017, https://doi.org/10.5194/angeo-35-87-2017, 2017
                                    Short summary
                                    Short summary
                                            
                                                A troposphere tomographic method has been proposed considering the signal rays penetrating from the side of the area of interest. Given the method above needs the establishment of a unit scale factor model using the radiosonde data at only one location in the research area, an improved approach is proposed by considering the reasonability of modelling data and the diversity of the modelling parameters for building a more accurate unit scale factor model.
                                            
                                            
                                        Y. B. Yao, Q. Z. Zhao, and B. Zhang
                                    Ann. Geophys., 34, 143–152, https://doi.org/10.5194/angeo-34-143-2016, https://doi.org/10.5194/angeo-34-143-2016, 2016
                                    Short summary
                                    Short summary
                                            
                                                Existing water vapor tomographic methods use Global Navigation Satellite System (GNSS) signals penetrating the entire research area while they do not consider signals passing through its sides.  To solve this issue, an approach which uses GPS data with both signals that pass the side and top of a research area is proposed. The advantages of proposed approach include improving the utilization of existing GNSS observations and increasing the number of voxels crossed by satellite signals.
                                            
                                            
                                        Wanqiang Yao, Haoran Huang, Xiongwei Ma, Qi Zhang, Yibin Yao, Xiaohu Lin, Qingzhi Zhao, and Yunzheng Huang
                                    Ann. Geophys., 42, 455–472, https://doi.org/10.5194/angeo-42-455-2024, https://doi.org/10.5194/angeo-42-455-2024, 2024
                                    Short summary
                                    Short summary
                                            
                                                There is limited discourse on the influence of the different analysis-center-based state-space representation (SSR) corrections on the accuracy of real-time zenith tropospheric delay (RT ZTD). Our primary objective is to compare the real-time precise point positioning (RT-PPP) performance and RT-PPP-derived ZTD accuracy and availability based on different SSR products. The findings serve as a valuable reference for selecting SSR products in RT-PPP-derived ZTD.
                                            
                                            
                                        C. Ouyang, J. Shi, W. Peng, X. Dong, J. Guo, and Y. Yao
                                    ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., X-1-W1-2023, 679–686, https://doi.org/10.5194/isprs-annals-X-1-W1-2023-679-2023, https://doi.org/10.5194/isprs-annals-X-1-W1-2023-679-2023, 2023
                            Pengfei Xia, Wei Peng, Shirong Ye, Min Guo, and Fangxin Hu
                                        EGUsphere, https://doi.org/10.5194/egusphere-2022-589, https://doi.org/10.5194/egusphere-2022-589, 2022
                                    Preprint archived 
                                    Short summary
                                    Short summary
                                            
                                                We first present a novel method of monitoring the UHI intensity using GNSS data. We overcomes two major challenges in the algorithm development. The first challenge is the determination of the GNSS tomographic top grid height, and the second challenge is the estimation of temperature from wet refractivity. The result shows that the proposed algorithm can achieve an accuracy of 1.2 K at a 95 % confidence level.
                                            
                                            
                                        Yibin Yao, Linyang Xin, and Qingzhi Zhao
                                    Ann. Geophys., 37, 89–100, https://doi.org/10.5194/angeo-37-89-2019, https://doi.org/10.5194/angeo-37-89-2019, 2019
                                    Short summary
                                    Short summary
                                            
                                                In this paper, we propose an improved pixel-based water vapor tomography model, which uses layered optimal polynomial functions by adaptive training for water vapor retrieval. Under different scenarios, tomography results show that the new model outperforms the traditional one by reducing the root-mean-square error (RMSE), and this improvement is more pronounced, at 5.88 % in voxels without the penetration of GNSS rays. The improved model also has advantages in more convenient expression.
                                            
                                            
                                        Zhaohui Xiong, Bao Zhang, and Yibin Yao
                                    Ann. Geophys., 37, 25–36, https://doi.org/10.5194/angeo-37-25-2019, https://doi.org/10.5194/angeo-37-25-2019, 2019
                                    Short summary
                                    Short summary
                                            
                                                A comparison between the GNSS tomography technique and WRFDA in retrieving wet refractivity (WR) is conducted in HK during a wet period and a dry period. The results show that both of them can retrieve good WR. In most of the cases, the WRFDA output outperforms the tomographic WR, but the tomographic WR is better than the WRFDA output in the lower troposphere in the dry period. By assimilating better tomographic WR in the lower troposphere into the WRFDA, we slightly improve the retrieved WR.
                                            
                                            
                                        Qingzhi Zhao, Kefei Zhang, and Wanqiang Yao
                                    Ann. Geophys., 37, 15–24, https://doi.org/10.5194/angeo-37-15-2019, https://doi.org/10.5194/angeo-37-15-2019, 2019
                            YiBin Yao and YuFeng Hu
                                    Ann. Geophys., 36, 1507–1519, https://doi.org/10.5194/angeo-36-1507-2018, https://doi.org/10.5194/angeo-36-1507-2018, 2018
                            Qingzhi Zhao, Yibin Yao, and Wanqiang Yao
                                        Ann. Geophys. Discuss., https://doi.org/10.5194/angeo-2018-76, https://doi.org/10.5194/angeo-2018-76, 2018
                                    Manuscript not accepted for further review 
                                    Short summary
                                    Short summary
                                            
                                                This paper captures the signature of heavy rainfall events using the 2-d-/4-d water vapour information derived from GNSS measurement in Hong Kong. The paper first analyzed the relationship between the two-dimensional (2-d) precipitable water vapour (PWV) and rainfall. And then, the four-dimensional (4-d) variations of atmospheric water vapour derived from the GNSS tomographic technique  are discussed, especially in the vertical irection. Finally, some interesting results are found and presented.
                                            
                                            
                                        Yibin Yao, Xingyu Xu, and Yufeng Hu
                                        Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2018-227, https://doi.org/10.5194/amt-2018-227, 2018
                                    Revised manuscript not accepted 
                            Pengfei Xia, Shirong Ye, Peng Jiang, Lin Pan, and Min Guo
                                    Ann. Geophys., 36, 969–978, https://doi.org/10.5194/angeo-36-969-2018, https://doi.org/10.5194/angeo-36-969-2018, 2018
                                    Short summary
                                    Short summary
                                            
                                                We proposed a new method to determine the scale height of water vapor, which will improve the quality of vertical constraints. Then, the smoothing factor in the horizontal constraint was determined based on ERA-Interim products. The evaluation results show that the water vapor density quality obtained by the optimized technique is 13.8 % better below 3.8 km and 8.1 % better above 3.8 km than that obtained by the traditional technique.
                                            
                                            
                                        Qingzhi Zhao, Yibin Yao, and Wanqiang Yao
                                    Ann. Geophys., 35, 1327–1340, https://doi.org/10.5194/angeo-35-1327-2017, https://doi.org/10.5194/angeo-35-1327-2017, 2017
                            Pengfei Xia, Shirong Ye, Kecai Jiang, and Dezhong Chen
                                    Atmos. Meas. Tech., 10, 1813–1821, https://doi.org/10.5194/amt-10-1813-2017, https://doi.org/10.5194/amt-10-1813-2017, 2017
                                    Short summary
                                    Short summary
                                            
                                                This study focused on the extraction of the atmospheric excess phases using the non-difference  processing strategy. The COSMIC POD processing is used to accurately determine the position and velocity of the centre of mass of the satellite and the receiver offset based on PANDA software. Finally, the bending angle, refractive and dry temperature profiles are taken from AEP using ROPP software.
                                            
                                            
                                        Qingzhi Zhao and Yibin Yao
                                    Ann. Geophys., 35, 87–95, https://doi.org/10.5194/angeo-35-87-2017, https://doi.org/10.5194/angeo-35-87-2017, 2017
                                    Short summary
                                    Short summary
                                            
                                                A troposphere tomographic method has been proposed considering the signal rays penetrating from the side of the area of interest. Given the method above needs the establishment of a unit scale factor model using the radiosonde data at only one location in the research area, an improved approach is proposed by considering the reasonability of modelling data and the diversity of the modelling parameters for building a more accurate unit scale factor model.
                                            
                                            
                                        Shirong Ye, Pengfei Xia, and Changsheng Cai
                                    Ann. Geophys., 34, 789–799, https://doi.org/10.5194/angeo-34-789-2016, https://doi.org/10.5194/angeo-34-789-2016, 2016
                                    Short summary
                                    Short summary
                                            
                                                The near-real-time high spatial resolution of atmospheric water vapor distribution is vital in numerical weather prediction. GPS tomography technique has been proved effectively for three-dimensional water vapor reconstruction. In this study, the tomography processing is optimized in a few aspects by the aid of radiosonde and COSMIC historical data, including the accuracy improvement of tropospheric zenith hydrostatic delay and precipitable water vapor conversion factor.
                                            
                                            
                                        Yibin Yao, Yufeng Hu, Chen Yu, Bao Zhang, and Jianjian Guo
                                    Nonlin. Processes Geophys., 23, 127–136, https://doi.org/10.5194/npg-23-127-2016, https://doi.org/10.5194/npg-23-127-2016, 2016
                                    Short summary
                                    Short summary
                                            
                                                By considering the diurnal variations in zenith tropospheric delay (ZTD) and modifying the model expansion function, we developed an improved global empirical ZTD model GZTD2 with higher temporal and spatial resolutions compared to our previous GZTD model. The external validation testing with IGS ZTD data shows the bias and rms for GZTD2 are −0.3 and 3.9 cm respectively, indicating higher accuracy and reliability for geodesy technology compared to GZTD and other commonly used ZTD models.
                                            
                                            
                                        Y. B. Yao, Q. Z. Zhao, and B. Zhang
                                    Ann. Geophys., 34, 143–152, https://doi.org/10.5194/angeo-34-143-2016, https://doi.org/10.5194/angeo-34-143-2016, 2016
                                    Short summary
                                    Short summary
                                            
                                                Existing water vapor tomographic methods use Global Navigation Satellite System (GNSS) signals penetrating the entire research area while they do not consider signals passing through its sides.  To solve this issue, an approach which uses GPS data with both signals that pass the side and top of a research area is proposed. The advantages of proposed approach include improving the utilization of existing GNSS observations and increasing the number of voxels crossed by satellite signals.
                                            
                                            
                                        P. Jiang, S. R. Ye, Y. Y. Liu, J. J. Zhang, and P. F. Xia
                                    Ann. Geophys., 32, 911–923, https://doi.org/10.5194/angeo-32-911-2014, https://doi.org/10.5194/angeo-32-911-2014, 2014
                            Y. B. Yao, X. X. Lei, Q. Liu, C. Y. He, B. Zhang, and L. Zhang
                                        Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhessd-2-3533-2014, https://doi.org/10.5194/nhessd-2-3533-2014, 2014
                                    Manuscript not accepted for further review 
                            P. Xia, C. Cai, and Z. Liu
                                    Ann. Geophys., 31, 1805–1815, https://doi.org/10.5194/angeo-31-1805-2013, https://doi.org/10.5194/angeo-31-1805-2013, 2013
                            Y. B. Yao, P. Chen, S. Zhang, and J. J. Chen
                                    Nat. Hazards Earth Syst. Sci., 13, 375–384, https://doi.org/10.5194/nhess-13-375-2013, https://doi.org/10.5194/nhess-13-375-2013, 2013
                            Short summary
            This paper proposes an optimal tropospheric tomography approach with the support of an auxiliary area, which has the ability to use the signals crossing out from the top boundary of the tomographic area. Additionally, the top height of the tomography body is determined based on the average water vapour distribution derived from the COSMIC data. The compared result reveals the superiority of the proposed method when compared to the conventional method.
            This paper proposes an optimal tropospheric tomography approach with the support of an auxiliary...
            
         
 
                        
                                         
                        
                                         
                        
                                         
                        
                                         
                        
                                         
                        
                                         
             
             
             
            