> "A.Brown" wrote:
>... a "Sun referenced satellite finder"
This is a page included on the NASS Link page. I think he is doing what
you want to do.
http://www.sundialsetup.com/
Bob Terwilliger
NASS Webmaster
>
> Fellow dial list
> Sun worshipers come in all guises, my relative living in Australia
> follows the sun to the Northern Territories on an annual basis,
> migrating south again to Esperance (WA) for the summer season. Happy
> at
> forgoing fixed home comforts she pines for helpings of television soap
>
> opera to break the monotony of wild bush evensong (everything in life
> is
> relative).
> In exchange for lodgings and a 500 mile lift to a scratch in the sand
> on
> the Nullarbor Plain to witness Decembers Solar Eclipse I have
> foolishly
> promised to design and build a "Sun referenced satellite finder"
> The "instrument" is to enable them to easily point their dish at a
> range
> of satellites from virtually anywhere in Australia throughout the year
>
> by referencing the altitude and azimuth directions of the dish
> relative
> to the suns known location.
> Ideally the 1.2M dish would be marked up with lines showing particular
>
> satellites and intersecting lines showing the time of day the dish
> simply being moved to cast a bright spot at the required intersection
> or
> its interpolation.
> Since they would not necessarily know their exact location it may be
> that the process would have to be two stage with say a bubble built
> into
> the dishes altitude adjustment to determine latitude.
> This could also be used to set the polar mount axis to allow the dish
> to
> "sweep" the Clarke belt.
> The idea is to temporarily replace the prime focus satellite parabolic
>
> dish's LNB with an orifice plate capable of setting one of the
> required
> variables probably the date.
> I imagine this to be two coaxial disk on a common 40mm diameter axle
> which can be substituted for the LNB.
> One or perhaps both the disk could be rotated with the lower disk
> having
> an annelema slot and the upper a radial slot. This would give an
> aperture whilst of variable shape at a known position. The axle would
> be
> referenced to the clamp and hence the dish.
> The disk would be sized to cast a good shadow to give maximum contrast
>
> for the bright spot in the strong sunlight, whilst still allowing
> sufficient ambient light to read the designations.
> Has anyone built such a device, or think it feasible, I understand 1/2
> a
> degree aiming accuracy should be sought.
> How would early Radio Telescope dishes like Jodrell Bank be first
> "calibrated"??
> I know John Davis gave a lively talk at a previous BSS meeting
> regarding
> the delineating of a dish as a sundial, I believe this may have
> involved
> covering the dish with a Mylar membrane.
> I hope I don't have to admit defeat and take out one of those awful
> microprocessor based finders!
