The curve is generated very crudely with the “slice” function in iris. This is then saved as a text file with the relative intensities.
It is then dropped into either excel for a quick look, like this, or GNUplot for a more upmarket finish.
Yes, the devices are interlaced. this is what generates the spikey appearence as the meteor moves.
And, no there is no dark subtraction. At video rates the noise level is already quite low so I’ve never bothered with it. The real problem is good flat fielding. That’s a different challenge!