Development of very sensitive heterodyne spectrometer at millimeter and infrared wavelength for strato-mesospheric atomospheric minor components

地面微波传感器通常用于通过被动探测臭氧等关键平流层分子的旋转跃迁来遥感痕量组分。与其他技术相比，这种方法在测量分子的日变化和短期变化方面具有独特的优势。微波观测测量分子的热发射，因此测量不需要像吸收测量那样的背景辐射源。观测也不需要晴朗的天空，而且可以全天候测量。但是，传统的臭氧监测方法不能很好地实时监测浓度和高度分布。因此，我们开发了一种使用超导-绝缘体超导混合器的系统，该系统具有迄今为止最好的噪声特性。总结我们仪器获得的观测结果，我们得出如下结论：1.混合比在不同高度(36-75公里)的日变化与理论计算和许多作者的观测结果一致，但在中层顶部附近的夜间变化除外。70公里左右的臭氧混合比表现出昼夜变化，其变化幅度约为午夜值的20%，日出前和日落后的臭氧混合比随时间的变化由积分时间为3分钟的观测得到

Ground-based microwave sensor are commonly used in remote sensing of trace constituents by passive sounding of rotational transition of key stratospheric molecules, such as ozone. This method has a distinctive advantage for measurements of diurnal and short term variations over other techniques.The microwave observations measure thermal emission of molecules and then measurement dose not require a background radiation source like the sun as is the case in absorption measurement.The observations does not also require a clear sky and measurements can be made throughout the day and the night.However, conventional ozone monitoring method do not enceble satisfactory realtime monitoring of concentration and altitude distribution.Accordingly we have developed a system using superconductor-insulator superconductor (SIS) mixer having the best noise characteristics reported to date.Summarizing observations obtained by our instrument, we may conclude as follows.1. Diurnal variations of the mixing ratio at various altitudes from 36 through 75 km appear in agreement with theoretical calculations and observations by many authors except night-time variations near the top of the mesosphere.2. The ozone mixing ratio about 70 km shows night-time variation variable from day to day with an amplitude of about 20% of the midnight value.Time variations of the mixing ratio just before the sunrise and after the sunset are obtained from observations with an integration time of 3 minutes