高斯函数在香港地区对流层层析实验中的应用

发布时间：2018-02-11 15:37

本文关键词： 全球定位系统斜路径湿延迟对流层层析垂直约束高斯函数　出处：《武汉大学学报(信息科学版)》2017年08期 　论文类型：期刊论文

【摘要】：将GPS信号的斜路径湿延迟当作层析的观测量能够有效获取对流层的三维水汽场。由于射线分布的不均匀和观测网地形的扁平,观测方程是不适定的,因此需要添加一些约束条件来确定唯一解。由于水汽在垂直方向变化很快,合理的垂直约束在获取准确的水汽场上起着重要作用。研究了香港地区湿折射率的垂直分布特征,发现高斯函数能很好地表达湿折射率与高度的关系,利用高斯函数建立约束方程获得的层析解能很好地与探空数据和欧洲中尺度天气预报中心(ECMWF)数据吻合。相对于指数约束所得结果,层析湿折射率的标准差在整个对流层减小了3.8mm/km,在低对流层减小了4.7mm/km。实验也表明,利用其他气象数据,如无线电探空数据,作为湿折射率的先验信息,也可以得到较好的层析解。
[Abstract]:The moisture delay of oblique path of GPS signal can be regarded as the observation quantity of tomography to obtain the three-dimensional water vapor field in the troposphere effectively. Because of the uneven ray distribution and the flat topography of the observation network, the observation equation is ill-posed. Therefore, it is necessary to add some constraints to determine the unique solution. Due to the rapid change of water vapor in the vertical direction, reasonable vertical constraint plays an important role in obtaining accurate water vapor field. The vertical distribution characteristics of wet refractive index in Hong Kong are studied. It is found that Gao Si function can well express the relationship between wet refractive index and height. The chromatographic solutions derived from the constraint equation established by Gao Si function are in good agreement with the sounding data and the ECMWF data of the European Center for Mesoscale Weather Prediction. The standard deviation of the wet refractive index decreases by 3.8 mm / km in the whole troposphere and 4.7 mm / km in the lower troposphere. The experiment also shows that using other meteorological data, such as radiosonde data, as the prior information of the wet refractive index, a better chromatographic solution can also be obtained.
【作者单位】：武汉大学测绘学院;武汉大学地球空间环境与大地测量教育部重点实验室;地球空间信息技术协同创新中心;
【基金】：中央高校基本科研业务费专项资金(2014214020202) 国家测绘地理信息局测绘基础研究基金(13-02-09)~~
【分类号】：P228.4;P412

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