机载GNSS掩星观测反演大气折射率廓线研究

作为星载掩星技术的推广，基于飞机平台的无线电掩星技术备受关注。为了将机栽掩星技术更好地应用到工程实践中，文章通过介绍机载掩星探测的基本原理和主要特点、模拟仿真，对机载掩星的反演算法进行了探讨，并给出模拟结果：包括利用STK仿真软件生成仿真场景；采用3维射线追踪技术模拟机载无线电掩星，预报掩星事件出现的时间、仰角，模拟信号传播特征；详细研究大气层内折射率反演技术并给出反演结果。研究结果表明，模拟仿真对机载掩星工程化实现是有益的。最后展望了机载掩星探测的发展趋势，提出了弱掩星信号的捕获跟踪、飞机平台的精度定位测速以及反射信号的抗干扰三项技术及工程化中需解决的技术难点。

Profiling the Atmosphere Refractivity Using the Airborne GNSS Radio Occultation Sounding

As an extended technique of GNSS radio occultation(RO),the airborne RO sounding has attracted much wider attention.In order to apply it in practical engineering,this paper firstly introduces some keystone and main features of airborne RO sounding.Then the simulation of the refractivity reversed is done and the reversed results are presented,including: establishing simulated scene by STK software;simulating airborne RO by 3D radial tracing technique to predict occultation occurring time,elevation and signal propagation feature;investigating refractivity reversed technique within the atmosphere.The simulated result is useful to airborne RO engineering.Some conclusions and prospect of airborne RO sounding are discussed.Finally,the paper points out that three technical difficulties in application are tracking weak RO signal,precisely measuring speed of airborne,and anti-jamming of reflection.