Randall Clague wrote: > > On Sun, 17 Nov 2002 10:58:52 -0800, David Weinshenker > <[EMAIL PROTECTED]> wrote: > > >And I'm not at all sure that the accel data are to be trusted... when > >we do the all-up static firing, I wanna borrow back my 'scope from > >the gizmocopter team and put it right on the cable from the chamber > >pressure transducer. I think there may be higher frequency stuff going > >on in there, and we're not seeing a true image of it in our A/D sampled > >readouts. > > Total amplitude should be the same, though, right?
Good question... sampling a signal with components of higher frequency than half the sample rate introduces weird "alias" artifacts; the answer to your question then becomes "maybe, but you really can't trust it even that far." A vibration with a frequency that's an exact multiple of the sample rate might cancel out completely, or appear as a steady high or low level, for example, depending on the relative phase of the signal frequency and sample rate. -dave w _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
