A Global Conversion Factor Model for Mapping Zenith Total Delay onto Precipitable Water

Remote Sensing

Lichuan Chen¹  Weiming Liao¹  Kang Liu²  Qingzhi Zhao²  Yun Shi²  Tengxu Zhang³  Lin He³  Ziyu Shen³  Si Xiong⁴ 

[1] Chongqing Institute of Geology and Mineral Resources, Chongqing 402574, China;College of Geomatics, Xi’an University of Science and Technology, Xi’an 710054, China;College of Resources and Environmental Science and Engineering, Hubei University of Science and Technology, Xianning 437100, China;School of Geodesy and Geomatics, Wuhan University, Wuhan 430072, China;

关键词: ZWD;    PWV;    GGOS Atmosphere;    GΠ model;   

DOI  :  10.3390/rs14051086

来源: DOAJ

【 摘 要 】

The conversion factor is a key parameter for converting zenith wet delays (ZWD) into precipitable water vapour (PWV) with a mean value of 0.15, and the traditional method of calculating it is to model the weighted average temperature in the process of conversion factor calculation. Here, we overcome the dependence on high-precision atmospheric weighted average temperature for mapping ZWD onto PWV and build a global non-meteorological parametric model for conversion factor GΠ model by using the gridded data of global conversion factor time series from 2006 to 2013 provided by the Global Geodetic Observing System (GGOS) Atmosphere. Internal and external accuracy tests were performed using data from four times (UTC 00:00, 06:00, 12:00, and 18:00) per day throughout 2012 and 2014 as provided by the GGOS Atmosphere, and the statistical average root-mean-square (RMS) and mean absolute errors (MAE) on a global scale are 0.0031/0.0026 and 0.0030/0.0026, respectively, which only account for 1.5–2% of the conversion factor value. In addition, the observed GPS data are also used to validate the established GΠ model, and the RMS of the PWV differences between the established model and the observed meteorological data was less than 3.2 mm. The results show that the established GΠ model has a high accuracy, which can be used to calculate the PWV value where no observed meteorological parameters are available.

【 授权许可】

Unknown