抄録
The Fourier Transform Spectrometer (FTS) is a powerful tool for measuring weak radiations with high spectral resolution, by virtue of its multiplex advantage. However, to fully appreciate this advantage, we have to be patient during a time for the acquisition of an interferogram that is to be converted to a spectrum of the band concerned. In case of the FTS of GOSAT (Greenhouse gases Observing Satellite), it takes four seconds for obtaining an interferogram of Earth-reflected solar radiations. To observe the reflected solar radiation from the Earth from moving satellite in space, we encounter a difficulty that during the acquisition of the interferogram, the optical characteristics of instantaneous filed of view (IFOV) could change. One of the causes of IFOV radiance fluctuation is the fluctuation of line-of-sight of the spectrometer, which is induced by the image motion compensation (IMC) of scanning mirror. Simulations showed that such disturbances could generate serious errors in CO2 retrieval. A method has been shown by Aoki et al. (2006)1) to correct this type of disturbances in the interferograms. The disturbance to IFOV radiance could also be induced by other causes. In this paper, we examine the effects of pulse-like glittering caused by the reflection from roof of houses, cars or others, and show the same correction method to the interferogram as that adopted in IMC correction well works.
