利用射线追踪法分析三种典型对流层映射函数在中国区域的精度
Using Ray-Tracing to Analyse the Precision of Three Classical Tropospheric Mapping Functions in China
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摘要: 基于中国区域内8个气象站点2012年全年的探空数据,采用射线追踪法计算了各个站天顶方向至4°高度角区间内18个方向的对流层流体静力学和非流体静力学延迟量,将天顶延迟通过NMF、GMF和VMF1三种映射函数投影到各个高度角方向,与射线追踪法得出的延迟量进行比较,结果显示:①NMF有明显的季节性偏差,且精度与纬度存在强相关性;②VMF1的精度最高、稳定性最好,但在武汉、长沙等站点存在一定的季节性偏差;③GMF的精度介于NMF和VMF1之间。Abstract: Radiosonde data from 8 stations in China are analyzed based on ray-tracing technology. Hydrostatic and non-hydrostatic delays for 18 directions，from the zenith to 40 elevation，were computed.The results were compared with 3 mapping functions: NMF, UMF and VMFl，which demonstrate that: ①there is strong relation between the precision of NMF and the latitude of the station;②VMFl is the most precise and stable mapping function, but with certain seasonal variations when applied in WuHan，ChangSha and some other stations;③the precision of UMF falls between that of NMF and VMFl.
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