Fig. 5
From: A meteor shockwave event recorded at seismic and infrasound stations in northern Taiwan
The time-compressed schematic of the meteor trajectory. The two rectangular coordinate system (x, y, z) and (X, Y, Z; Z indicates the direction of approaching meteor) constrains the geographical and meteoric trajectory location in space, respectively. The dashed, thin, and bold red line segments represent the plane shockwaves location at time t 1, t 2, and t 3, respectively (t 3 > t 2 > t 1). The light and bold red-dashed ellipses approximately demarcate the region having relatively higher signal amplitude at time t 2, and t 3, respectively. The stations closer to the intercept of the protracted trajectory with the ground (termination point; O) encounter earlier shockwave arrival. \( \delta , \beta \), and \( \gamma \) are the elevation angle, the Mach angle, and the azimuth of the trajectory, respectively. The azimuth (\( \gamma ) \) is the angle measured from the geographic north to the horizontal projection of the Z-axis in the x–y plane, in the clockwise direction. The elevation angle (\( \delta ) \) is the minimum angle between the Z-axis (direction of approaching meteor) and the x–y plane