Vertical plasma density distribution (A, B) and true-height contours (C, D) over Dourbes during the eclipses of 3 October 2005 (A, C) and 20 March 2015 (B, D). The true-height contours, displayed for frequencies ranging from 2.8 MHz (bottom curve) up to 5.0 MHz (top curve), are obtained from Digisonde measurements. The shadings indicate the eclipse periods. The time resolution is 15 min for the 2005 eclipse and 5 min for the 2015 eclipse, except between 06:30 UT and 11:30 UT on 20 March 2015 when the resolution is 30 s.