Figure 4
From: Observations of GPS scintillation during an isolated auroral substorm
Selected ASC all-sky images together with the location of the satellites. (a to l) Selected ASC all-sky images together with the location of the satellites. The color of the point gives the PRN number of the satellite, and the grey points mean that the elevation angle of the satellite was less than the threshold of 30° when the signal was received. The times at which these images were taken are marked by the vertical dotted lines in Figure 3.