Figure 2. Sprite with green ghost recorded 25 May 2020 at 30 fps (33 ms
between mages). The green ghost reaches maximum intensity at t = 166 ms
and decays after that. The green in the green ghost images, images 2-6,
has been enhanced.
For analysis images were extracted from the videos and RGB color
components separated. To analyze altitude variations we extracted pixel
brightness integrated over 10 rectangular boxes covering the green ghost
(Figure 3). The green ghost appears on top of a relatively high
background which we subtracted. Both sprites were located southeast of
Lamy, NM, and assuming the sprite to be over the causal lightning strike
the altitude covered by the boxes varies from 97 km (box at the top) to
83 km (box at the bottom).