利用低轨道卫星间微波信号探测反演温湿廓线

通过同时测量微波信号的折射和吸收信息，低地球轨道卫星间（LEO-LEO）微波掩星探测技术能够独立反演温度和水汽廓线。通过仿真手段，首先，正演模拟了微波信号穿过大气层后由折射和吸收效应分别导致的相位延迟和振幅衰减，在此基础上，对温度、水汽和云中液态水反演廓线进行了个例分析，然后，统计分析了温度和水汽在不同纬度带的反演性能，以及云对反演精度的影响。结果表明：温度在约35 km以上存在明显正偏差，高纬度的最大，中纬度次之，低纬度最小。水汽反演误差在约4 km以下明显增大，低纬度的最大，中纬度次之，高纬度最小。有云存在时，需要去除云的吸收作用，否则温度和水汽会出现明显的正偏差。上述研究为进一步发展LEO-LEO掩星探测计划提供了理论参考依据。

Retrieval of temperature and water vapor profiles by measuring microwave signals between LEO satellites

LEO-LEO microwave occultation measurement technique can independently retrieve the temperature and water vapor profiles using both refraction and absorption measurements of microwave signals between LEO satellites. In this paper, the excess phase and atmospheric loss caused by refraction and absorption were simulated firstly. On this basis, the individual retrieval profile of temperature, water vapor and cloud liquid water content were analyzed. Then, the retrieval performance of temperature and water vapor profiles at different latitudes and the influence of cloud on the retrieval accuracy were statistically analyzed. The results show that the retrieved temperature profiles has significant positive bias above 35 km, with the largest in high latitude, the second in middle latitude, and the smallest in low latitude. The retrieval error of water vapor profiles increases significantly below 4 km, with the largest in low latitude, the second in middle latitude and the smallest in high latitude. In the cloudy atmospheric conditions, it is necessary to remove the absorption of clouds, otherwise the retrieved temperature and water vapor profiles will have positive bias. This study can provide theoretical reference for the further development of LEO-LEO occultation space exploration missions.