Dave, I launched one in my LOC Weasel clone on H73, Saturday ... the
altimeter read 3115'. my rocksim says 3135'. I'd say that's close
enough! now I have a calibrated rocksim and I am going to for exactly a
The best recording altimeters, judging from the data, are from
Adept. The data are filtered well enough that one can derive
velocity and acceleration from them - also thrust and Cd
curves with a little extra work in vertical flights. That's a lot
better than the data from other altimeters I've seen. Not
actually familiar with the PerfectFlite.
oh my goodness!!! I sure didn't mean it like that! I was not being
uncivil, the wikipedia entry for jerk is what I meant - 2nd derivative
of velocity. it made sense when I typed it late at night.
very sorry nad I hope everyone gets a laugh out of this.
I assume, by Jerk, you mean the third derivative
of altitude :-)
Adept altimeter data are good enough to be double differentiated
by Savitsky-Golay filters to give acceleration curves. They have
the opposite problem that accelerometers have. They measure
only in the vertical dimension To the extent that the trajectory is
vertical, the acceleration is righteous.
Had thought I'd made a breakthrough with this double differentiation,
but evidently the Adept software does it too.
BTW, I have traditionally been so far in the accelerometer camp that,
as far as I know, Tommy dislikes me. We have no connection whatever.
-Larry (Deriving the jerk could be stretching it) C.
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