Fig. 5
From: Imaging-based observations of low-latitude auroras during 2001–2004 at Nayoro, Japan
The aurora observed on May 31, 2001. The image is projected onto a map by assuming the altitudes of 150 km (left panel) and 400 km (right panel), respectively. The enclosed solid line with a trapezoidal-like shape shows the field-of-view of the camera system. The dotted grid lines show the geographical longitude and latitude. Thick solid lines show the magnetic latitudes and the corresponding L values. The location of Nayoro City is indicated with a plus symbol. Artificial objects (e.g., buildings and power lines), mountains, and structures below the horizon are masked with black color