Observation of monochromatic auroral images and date processing

• Main Authors: Takayuki Ono, Masaki Ejiri, Takeo Hirasawa
• Format: Article in Journal/Newspaper
• Language: English; Japanese
• Published: National Institute of Polar Research 1988
• Subjects: Geography (General); G1-922; Syowa Station; Antarc*; Antarctica; National Institute of Polar Research
• Online Access: https://doi.org/10.15094/00008575; https://doaj.org/article/67ff930887d5425396413b0d18c97506

A new TV camera was developed and applied to the auroral ovservation at Syowa Station, Antarctica, in 1984. The TV camera is to obtain monochromatic auroral images at the principal auroral emission lines such as 6300Å (OI), 5577Å (OI), 4861Å (Hβ) and 4278Å (1N N_2^+), and band (6000～8000Å; 1P N_2). An important merit of the new TV camera is digital recording of the observation data. Successive monochromatic auroral images transferred from the TV camera every few seconds are digitized and converted to digital data stream simultaneously and recorded by a high speed data recorder in a PCM format. Observations by using three sets of the TV cameras were carried out throughout the winter season in 1984 at Syowa Station by JARE-25 wintering party. The TV cameras were used also for cooperations with (i) sounding rocket experiments, (ii) auroral particles, plasma and plasma wave experiments on board the EXOS-C satellite and (iii) conjugate auroral observation campaign which was carried out in lceland. The data processing software system was established by using a host computer in the National Institute of Polar Research. We developed the data reproduction software to convert the PCM data to the computer compatible digital data. The data can be monitored by a display software which is also able to make a coordinate transform from the original TV image to an ionospheric geomagnetic coordinate system. By using this method, we found that a diffuse auroral band which is located equatorward of an oval of discreate auroras, corresponds to the proton auroral band in the evening sector. For a special purpose to analyze the pulsating auroral phenomena, we developed an autocorrelation analyses software which gives a two-dimensional display of periodicity and period of pulsating auroras. By using this analysis method, we found a grouping of pulsating auroras with respect to a two-dimensional distribution of periods of pulsating patches.