Hi Dominic,
The video camera will output 25 interlaced frames per second (PAL) and the VTI timestamps each video field, 50 per second. Many occultation (and meteor observers) record to AVI files using a USB video grabber. Limovie and Tangra can read and analyse these at the deinterlaced field level. We use this to get good time resolution (0.02s) on lunar occultations and bright asteroidal events…
https://www.britastro.org/node/8992
The pairs of video fields from an integrating video camera will give (almost) identical images.
UFO Analyser processes meteor AVIs at field level to estimate the meteor’s velocity.
Cheers,
Alex.