Acta Geodaetica et Cartographica Sinica ›› 2022, Vol. 51 ›› Issue (3): 327-339.doi: 10.11947/j.AGCS.2022.20210126

• Geodesy and Navigation • Previous Articles     Next Articles

An adaptive non-uniform vertical stratification for GNSS water vapor tomography

WANG Hao1, DING Nan1, ZHANG Wenyuan2, FENG Zunde1, ZHAO Changsheng1, YAN Xiangrong1   

  1. 1. School of Geography, Geomatics and Planning, Jiangsu Normal University, Xuzhou 221116, China;
    2. School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China
  • Received:2021-03-17 Revised:2022-12-20 Published:2022-03-30
  • Supported by:
    The Postgraduate Research and Practice Innovation Program of Jiangsu Province (No. KYCX20_2363); The National Natural Science Foundation of China (Nos. 41904013; 41774026; 41730109); The National Science Foundation of Jiangsu Normal University (No. 19XSRS010)

Abstract: GNSS tomography technique plays an important role in the monitoring and early warning of meso- and small-scale severe weather. Common GNSS tomography technique uses uniform stratification during vertical stratification, which does not consistent with the actual distribution of water vapor in the vertical direction. To resolve this problem, this paper proposes an adaptive non-uniform exponential stratification method that follows the dynamic exponential distribution of atmospheric water vapor. The proposed method greatly improves the accuracy of stratification of the tomographic model by reducing the difference in water vapor density of each layer. Moreover, it could adaptively calculate the optimal non-uniform vertical resolutions for any given tomographic region. This paper utilizes the Hong Kong Continuously Operating Reference Stations (CORS) measured data and radiosonde data in August 2019 to experiment and analyze the method. Compared with the traditional uniform stratification, the root mean squared error and the mean absolute error of the adaptive non-uniform exponential stratification are reduced by 0.40 g/m3 and 0.223 g/m3 respectively. In addition, the accuracy and quality of tomographic results are significantly improved at the lower height or in severe weather.

Key words: tropospheric water vapor tomography, global navigation satellite system, water vapor density, vertical stratification

CLC Number: