Fig. 21From: On the use of ELF/VLF emissions triggered by HAARP to simulate PLHR and to study associated MLR eventsSpectrograms recorded onboard DEMETER (top panel), at Chistochina (middle panel), and at Juneau (bottom panel) between 20:46:30 and 20:51:30 UT in the frequency range 0–4 kHz. The power spectral density is color-coded according to the scale on the rightBack to article page