Fig. 4From: Volcanic plume measurements using a UAV for the 2014 Mt. Ontake eruptionFlight routes for the campaign on June 2, 2015, plotted in the same map as in Fig. 1b. See text for details. Points t–w correspond to the data points on the time series plots of SO2 flux in Fig. 5c, d. A solid circle C corresponds to taking off and landing points in Fig. 1bBack to article page