Fig. 4
From: Transport of ballistic projectiles during the 2015 Aso Strombolian eruptions
An example of the velocity profile obtained from trajectory data. Red dots show the velocity in the horizontal direction, and blue dots show the velocity in the vertical direction. A light blue line shows the linear fitting of the vertical velocity, and the R2 value in the figure is its correlation coefficient. The vertical velocity at the vent height, shown with a yellow square, is estimated by extrapolating this linear fitting line