Retrieval of PWV Based on GPS and Multi-level Isobaric Surface Data
In GPS meteorology, the pressure and temperature parameters of GPS station are very important when obtaining accurate precipitable water vapor (PWV). However, there are few GPS stations equipped with co-located sensors for these meteorological parameters. In order to solve the problem, two methods, which is Parameter Conversion Method (PCM) and Layer Interpolation Method (LIM), were analysed and compared in this paper. The mean sea level products and multi-level isobaric surface products provided by NCEP for the period from Mar to June 2017 were used to two methods, respectively. Based on 36 GPS stations around the world which contain meteorology file and co-located radiosonde data, the experiment verified the availability and accuracy of two methods in obtaining meteorological parameters and further, PWV. Results show that: (1) both LIM and PCM works well when station height below 1600 m, the average bias of LIM is 0.67 hPa and 1.12 K compared with 0.9 hPa and 1.65 K of PCM; (2) with increasing of the station height, the difference between observed values and calculated values of pressure become larger, while the LIM has better accuracy than PCM and the robustness is better, the RMS is 2.54 and 2.91 hPa, 3.53 and 4.69 K, respectively; (3) The experiment results and analysis shown the validity of LIM and PCM, and the estimated PWV shows a higher accuracy using LIM.
KeywordsGPS meteorology PWV NCEP Interpolation
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