Development of portable-type laser heterodyne spectrometer for the observation of the ozone hole

便携式激光外差光谱仪设计于1992年，建成于1993年。它配备了四个可调谐二极管激光器，用于在8-11微米的波长范围内测量各种痕量气体。光学元件的重量为70公斤。与前者相比，光学元件的微调更加容易，并且减小了由于光反馈引起的激光不稳定性。这台光谱仪实现了极高的波数分辨率，每10分钟测量一次，波数分辨率达到0.0013 cm^~(-1)，每个光谱的信噪比都很高(通常O_3为1500，N_2O为500)。这些特征使我们能够从观测光谱中得出对流层和平流层中大气次要气体的高度分布。使用该便携式激光外差光谱仪进行了多次观测。在筑波和仙台观测到了臭氧、一氧化二氮和甲烷的垂直分布。1994年，在南极洲的西奥瓦空间站也进行了类似的观测。1996年和1997年，对臭氧、一氧化二氮和甲烷进行了观测，以验证ADEOS卫星上的RIS和ILAS仪器。因此，利用本研究开发的便携式激光外差光谱仪获得了有关臭氧消耗过程的重要信息。

The portable-type laser heterodyne spectrometer was designed in 1992 and its construction was completed in 1993. It is equipped with four tunable diode lasers for measurements of various trace gases in the wavelength region of 8-11 mu m. The weight of the optics is 70 kg. The fine adjustment of the optics is easier than the former type and the laser instability due to optical feedback is reduced. This spectrometer has realized an extremely high wavenumber resolution of 0.0013 cm^<-1> and a high signal-to-noise ratio (typically 1500 for O_3 and 500 for N_2O) for each spectrum measured every 10 minutes. These characteristics enable us to derive the altitude profiles of atmospheric minor gases in the troposphere and stratosphere from observated spectra. Many observations were performed using this portable-type laser heterodyne spectrometer. The vertical profiles of ozone, nitrous oxide, and methane were observed at Tsukuba and Sendai. In 1994, similar observations were carried out at Syowa station, Antarctica. In 1996 and 1997, observations of ozone, nitrous oxide, and methane were performed for the validation of RIS and ILAS instruments on board the ADEOS satellite. Thus, important information on the ozone depletion processes was obtained using the portable-type laser heterodyne spectrometer developed in this study.