Following last year's visit, we came again to the Kiruna Esrange Optical Platform Site (KEOPS) at the Sweden Space Center (SSC) in Esrange. The purpose of this visit was to expand the field of view of the hyperspectral camera installed last year. Prof. Ebihara of the Research Institute for Sustainable Humanosphere, Kyoto University, with whom I launched the aurora observation project, also joined us. The hyperspectral camera is a camera that can obtain two-dimensional images plus three-dimensional wavelength data, but it has been limited to an area of 45 degrees from the zenith. This time, its field of view was extended to 90 degrees. The work was done in the morning of the first day to finish before the weather turned bad; it started snowing in the afternoon of the second day and we could not go up to KEOPS on the hill. We stayed at the SSC guesthouse to check the aurora images and found that the hyperspectral camera provided almost the same field of view as the all-sky camera.

In addition to the SSC, there is a nearby aurora observation facility called IRF (Swedish Institute of Space Physics) in Kiruna. We visited there to analyze the hyperspectral camera data from last year. At the international conference on SMILE satellite observations held the next day, Dr. Yamauchi of IRF presented the results of the analysis.

This time, a red aurora was observed. Auroras have strong green light, but sometimes red light can be seen at the top of the aurora. The hyperspectral camera can precisely observe the wavelength of the light, which is useful for elucidating the emission mechanism of the red aurora.

So far so good, but on the morning of the day we left for the airport to return home, it snowed heavily, and as we left the gate of the SSC guard, our car got stuck because it could not climb the hill. We had a snowplow shovel the snow and tried again, but got stuck again. This meant that I could not return to Japan! When we were at a loss, the guard brought a wheel loader with a large amount of sand and spread it on the road. This idea worked, and we were finally able to climb the slope. Once up here, it was a gentle downhill to the airport. We managed to reach the airport.