Fitting rate against instantaneous speed produced a tidy "rate rises with speed"
relationship, with speeds up to 4795 when the craft's maximum is 1200. It is
entirely an artefact: 20 Hz polling is faster than the guest updates these fields,
so a per-read delta is either exactly zero (no update yet) or a whole frame's
worth divided by a fraction of a frame. 111 of 352 reads were zero on BOTH
channels -- position and attitude update on the same frame, so the two are
perfectly correlated, and dividing each by the short wall dt produced the
correlation out of nothing.
Fix: aggregate over windows spanning many frames (0.5 s). A sum of |delta| over
such a window is right however the updates fall inside it.
This does NOT affect the swept-total probes (roll_axis.py, rate_probe.py) -- they
already summed over the whole dwell, immune for the same reason. Only per-sample
instantaneous rates were ever wrong, so no earlier number moves.
The windowed re-run is NOT yet claimed as a result. It gives plausible magnitudes
but still shows rate rising with speed, against the definition's PitchPlus_Min 150
> _Max 70, and it has two disqualifiers: it ran on an instance where the craft was
already tumbling from the previous sweep, so pinning reported "WEAK -- craft may
not be level", and the sweep started mid-range rather than at maximum. A clean
answer needs a fresh flight with pinning CONFIDENT and nothing before it. Since
what is in doubt is precisely what _Min/_Max mean, a measurement through a
doubtful instrument cannot settle it.
Both datasets kept, the bad one labelled, because the aliased curve is a good
example of what a manufactured correlation looks like.
Claude (auto-RE)
0a84c1358e
