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 _______________________________________________ psas-avionics mailing list psas-avionics@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-avionics