【摘要】 无线电掩星技术是一种探测地球大气的崭新途径.菲涅耳衍射反演是GPS掩星技术中基于物理光学原理的新的反演方法.文章研究了菲涅耳及几何光学方法的反演原理,利用GPS/MET数据分别反演得到了大气折射率及温度廓线.对比分析了菲涅耳衍射方法在10Hz、25Hz和50Hz三个采样频率下不同的反演结果,通过与几何光学反演结果及相应探空数据的对比分析,表明菲涅耳衍射反演得到的结果在对流层,特别是水汽含量丰富的区域中更为准确可靠.更多还原

【Abstract】 The radio occultation technique is a new way to explore the Earth’s atmosphere. The Fresnel inversion based on the principle of wave optics is a new method to retrieve atmospheric profiles. In this paper, the Fresnel transform and the Geometric Optics (GO) inversion method are analyzed and compared. The limitations of the theories of these methods are analyzed. The advantage of the Fresnel method at different sampling rates 10 Hz, 25 Hz, 50 Hz is discussed. With the GPS/MET measurements, temperature profiles in the troposphere are retrieved. And then they are compared to the corresponding radiosonde data. Through the comparative analysis, it can be concluded that the Fresnel inversion method is more accurate in the troposphere, especially where the water vapor is abundant.更多还原