Keep in mind that all the instruments we used for those
velocity measurements have some interesting limitations at
this point. The pressure altimeter is known not to work so
well in the transsonic region. The z-axis IMU hasn't yet
been calibrated terribly effectively. The GPS is quite
inaccurate since we aren't yet using the doppler velocity,
if it even had lock at that point, which I doubt. So I'd
say it's easily possible that there is substantial error in
the TM velocity estimate.
Anyway, it's hopefully moot to some degree. We should fly
again in the Fall and have a better instrument package on
board, as well as a cleaner airframe with less fin angle and
flutter. I'm guessing we'll clear Mach 1 easily at that
point, and be able to easily determine this.
Bart
In message <4a254b05.70...@ytivarg.com> you wrote:
> Hi all,
>
> One slightly dispassionate observer out here thinks that transonic is
> feasible for this one, but probably not supersonic.
>
> mach 1 is 335 m/s measured at sea level at 59 deg. F. The speed goes
> down as as elevation, altitude, humidity and air temperatures increase.
> (Lower air density.) A nice hot humid day, launching from central
> Oregon, plus a few hundred meters of altitude and the speed of sound
> _might_ have been around that magic 308 m/s mark.
> --
> Richard Johnson
> KQ7O
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