[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Optical Tracking?



Between 0.5 and 2 RPM maybe?

Bob

On Wed, 3 Oct 2001, Louis A. Mamakos wrote:

>
> I found some recent NORAD elements for PCSAT, and plugged them into my
> plantarium program. If I can get the rectangular field of view parallel
> to the path of the satellite, it looks like it will take 17 seconds
> to cross my CCD detector's field of view. I've got 500 pixels of
> resolution in that dimension, or about 34 milliseconds per pixel at
> that rate. I'm guessing that I'd be luckly to resolve detail smaller than
> a couple of pixels, so figure closer to 70 milliseconds of resolution.
> This with a 480mm focal length instrument.
>
> If it's spinning much faster than that, then with my longer focal length
> instrument (1099mm) it will take about 7 seconds to cross the field
> of 500 pixels.
>
> Hmm.. this might just be doable given sufficiently accurate TLE's so
> that the scope can get aimed at the right part of the sky.  My
> telescope mount should be able to hack the 20 arc minutes, no problem,
> especially since I can verify the position by observing the stars
> in the background.
>
> louie
> wa3ymh
>
> camera: http://www.starlight-xpress.co.uk/Test/mx5.htm
> mount:  http://www.astro-physics.com/products/mounts/900gto/900gto.htm
> telescopes:
>         http://www.astro-physics.com/products/telescopes/155edfs/155edfs.htm
>         http://www.company7.com/televue/telescopes/ranger.html
>
>
> http://www.astro-physics.com/
> > It moves through say 90 degrees of arc in about 2  minutes maybe...
> > You should see it witn binoculars, so a viewfinder would work better.
> >
> > bob
> >
> > On Wed, 3 Oct 2001, Louis A. Mamakos wrote:
> >
> > >
> > > Bob,
> > >
> > > I've got a a telescope mount with great positioning accuracy (on the
> > > order of 10 arc minutes or so).  What would be helpful is a back-of-the
> > > envelope computation of what the apparent motion of the satellite is,
> > > say within a 1 degree field of view, and if we'd be likely to see
> > > enough blinks during that time to get meaningful measurements.   So,
> > > we could part our telescope on a part of the sky, and wait for PCsat
> > > to fly through the field, rather than trying to actively track it.
> > >
> > > I don't recall what the computed apparent magnitude was likely to be; but
> > > I suspect that with my 6" f/7 refractor, I ought to be able to see it.
> > > Visually, even in my light polluted area, I can go to at least mag 9 or
> > > better.
> > >
> > > Alternatively, if the apparent motion is small enough, I should be able
> > > to do a long-exposure CCD integration and see the light come and go.
> > > Working backwards, the blinking rate should be computable.  Even with
> > > a 70mm f/6.8 scope, giving a much larger field of view, I suspect the
> > > CCD camera would be able to image the beacon blinking on and off.
> > >
> > > I'd be interested in trying something like this, please let me know
> > > if you continue to pursue this approach.
> > >
> > > louie
> > > wa3ymh
> > >
> >
> > de WB4APR@amsat.org, Bob
> >
> > ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
> > PCsat Design        http://www.ew.usna.edu/~bruninga/pcsat.html
> > CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
> > APRS LIVE pages     http://www.ew.usna.edu/~bruninga/aprs.html
> > APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html
> > MIM/Mic-E/Mic-Lite  http://www.toad.net/~wclement/bruninga/mic-lite.html
>

de WB4APR@amsat.org, Bob

ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
PCsat Design        http://www.ew.usna.edu/~bruninga/pcsat.html
CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
APRS LIVE pages     http://www.ew.usna.edu/~bruninga/aprs.html
APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html
MIM/Mic-E/Mic-Lite  http://www.toad.net/~wclement/bruninga/mic-lite.html

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home