联合地基GNSS及空基GNSS掩星探测水汽三维分布

研究了联合地基GNSS和空基GNSS掩星观测的大气水汽探测方法。首先,利用COSMIC(气象、电离层、气候星座观测系统)和GRACE(重力恢复与气候实验)无线电掩星产品对对流层层析成像的几个关键技术进行了优化,标定了对流层干延迟模型,建立了新的大气加权平均温度模型,提出了一种新方法用于确定水汽层层顶(即对流层层析模型的顶部边界)。选择香港地区12个连续GNSS气象监测站2017年6月份的数据反演计算了水汽的三维分布,以探空测站的水汽密度为真值,统计层析反演结果与真值之间的偏差为:偏差平均值优于1.36g/m^3,RMS值优于1.70g/m^3。

Remote Sensing the Atmospheric Water Vapor Using Observations from the Ground-based GNSS Network and Space-based Radio Occultation

This study focus on the retrieval of atmospheric water vapor by jointly using ground-based GNSS and space-based occultation observations. First of all, several key techniques of tropospheric tomography are optimized using COSMIC (The Constellation Observing System for Meteorology, Ionosphere, and Climate) and GRACE (Gravity Recovery and Climate Experiment) occultation products. The tropospheric hydrostatic delay model is calibrated, a new atmospheric weighted mean temperature model is built, and a new method is proposed to determine the top of water vapor,namely the top boundary of troposphere tomographic model. GPS datasets collected over June 2017 in Hong Kong are used to invert the 3D distribution of water vapor. And the water vapor density product of the 45004 sounding station is considered as the true value. Compared with the radiosonde, the Mean and RMS of differences between water vapor densities derived from tomography and radiosonde are better than 1.36g/m3 and 1.70g/m3, respectively.