An example of the output of the automatic bubble detection tool for BAKO receiver, 12 October 2014 and satellite 21. Upper panel: Estimated TEC from LI (TECU) (light green dots), TEC from PI (TECU) (blue dots), the 5-point running means smoothed TEC from PI (TECU) with an elevation mask of 20° (red dots) and the predicted background TEC from LI (TECU) (dark green line). Vertical lines whose values are shown in the legend mark T ₀ and T _f. Middle panel: SIGMA(2DTEC) (TECU), where the horizontal blue line indicates the threshold value (0.075 m² = 0.714 TECU) defining T ₀ and T _f, and in turn ETD. Bottom panel: Difference between predicted background TEC and estimated TEC, ∆TEC(t) (TECU), from which we calculate the bubble Depth and the total disturbance TDB.