Fig. 1From: Periodic oscillations of Doppler frequency excited by the traveling ionospheric disturbances associated with the Tonga eruption in 2022The maps of Japan. The left panel (a) and right panel (b) show the western and eastern parts of Japan, respectively. The red triangles and circles show the locations of the transmitters and receivers, respectively. The crosses show the midpoints of the transmitters and receiversBack to article page