Sounds like an interesting potential method for observing invisible plumes.
The old RRC test site crew here doesn't recall you having proposed such a thing.. Our plumes were generally pretty visible, and I suspect that any lack of interest would have been because we didn't need such technology. Ken Doyle > > From: Doug Jones <[EMAIL PROTECTED]> > Date: 2003/11/18 Tue PM 01:11:56 EST > To: [EMAIL PROTECTED] > Subject: Re: [ERPS] Armadillo Nov 15 > > Alex Fraser wrote: > > > I think a bright light reflected reflected from a projection screen > > (like for a slide show) will give you enough bright defused light to see > > the refraction differences from the shock waves in the plume. Anybody > > got an old slide projector and screen? You might have to do some > > processing tricks with the video to see the plume clearly, contrast and > > edge detection perhaps? > > Ah, yes- I tried to get this set up at RotRock back in '98. The best > cheap method is to get a sheet of Scotchlite or some such > retroreflector, place it behind the plume, and illuminate it coaxially > with the camera- just like a front-projection unit as used in video & > movie production. I've checked out the effect with an 8x11 inch panel > built up from strips of reflective tape and a flashlite held alongside > my head- it shows the heat shimmers from a match remarkably well, and > the density variations of a rocket plume will be dramatic. I also > tried it with the flow from a simple air nozzle, and I could see the > mach disks & mixing region. I never did manage to get the RRC test > site crew to buy into it, though. > > For best results, a half silvered mirror can be used to provide a > truly coaxial light source, but that may be overkill. Maybe even two > cameras and two lamps could be used with the same reflector panel to > produce stereo images... > > Okay, now I have to scrounge up the parts and try it with the teacart > engine, although a high intensity flash might be needed in this case > to wash out the visible plume. I'll post pics. > > Doug > > _______________________________________________ > ERPS-list mailing list > [EMAIL PROTECTED] > http://lists.erps.org/mailman/listinfo/erps-list > _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
