One launch, several recordings
Each stage of a staged flight lands on its own altimeter, so no single file holds the flight — and the thing none of them has on its own is the order. Debrief lines them up on the launch, the one instant every stage shares, and shows every mark in sequence with the recording it came from. Nothing is merged into a single reading.
Looking for the recordings…
Where the numbers come from
Debrief is a measurement instrument, not a simulator: every number is a reading of your own recording, worked out the same way for every logger and labelled wherever it's derived or approximate. See exactly how each one — apogee, velocity, thrust-to-weight, drag and parachute Cd, recovery drift and the rest — is calculated, and where it can be wrong.