One of the projects I am using lisp and the stepper motors for is to
drive the tracking system of a home-made telescope. There are two
motors involved, one driving the verticle aspect, a second driving the
horizontal aspect. muLisp function TIME returns 1/100 of second since
an internal real time clock was reset. When the program starts it
setq's a *time-mark*, the revolutions the horizontal and verticle motors
must make to track the target are calculated using well documented (and
down loadable from several sites) astromonical equations. (my only
problem is to translate the equation's output into stepper revolutions
at my drive system's "clock speed")
At this point I am working on the drive train and the various gear
ratios to properly regulate the "clock speed" of the drive system. My
question is......would you pre-calculate the tracking locus on program
startup and push them onto a list with the time they should be sent to
the steppers or get the elapsed time each loop, calculate the
revoultions _real time_. The project is somewhat simpfied because the
telescope is not portable so the latitude and longitude are fixed.
Well I guess better than giving you only two options.......generally
what approach do you think you would take in a lisp program to tranlate
elasped time into verticle and horizontal rotations?
Hey, just think I might find an asteriod....just hope it's not _the
asteroid_.
rusty
ps if Charles (sorry what's his name) can do it in forth, surely I can
do it in muLisp :)
rusty craine wrote:
> One of the projects I am using lisp and the stepper motors for is to
> drive the tracking system of a home-made telescope.
http://zebu.uoregon.edu/~mbartels/altaz/altaz.html
Here is link I should have posted with the first posting....just incase you
decided you need to start building a telescope too.
rusty craine <········@flash.net> writes:
-> Well I guess better than giving you only two options.......generally
-> what approach do you think you would take in a lisp program to tranlate
-> elasped time into verticle and horizontal rotations?
->
-> Hey, just think I might find an asteriod....just hope it's not _the
-> asteroid_.
The Earth is being hit by rocks every day...
Does this telescope record its image on film/ccd or an eyeball? The
earth's rotation is constant, so you can pre-calculate the rate that
the steppers need to move. You will also need to work out the drift
in the clock so that you can keep a star fixed in the field of view.
You are a true hacker, Rusty.
--
David Steuber
http://www.david-steuber.com
s/trashcan/david/ to reply by mail
"Hackers penetrate and ravage delicate, private, and publicly owned
computer systems, infecting them with viruses and stealing materials
for their own ends. These people, they're, they're terrorists."
-- Secret Service Agent Richard Gill
David Steuber wrote:
>
>
> Does this telescope record its image on film/ccd or an eyeball?
>
Well right now I've got a 35 mm cannon hooked up to it. As soon as I get the
telescope motorized, I am going to put ccd on it. I have down loaded the
schematics and started buying the pieces for the ccd.
I really went all out on my telescope it is a 16" dobsonians. I've been
putting it together for about 24 months now so the cost was spread out over
sometime. Lucky we (my wife and I) have a ranch an hour outside of town. It
has the highest point on it for several miles around....great place to put my
scope.
look at the stars
rusty
from dialogue between Rusty Craine and David Steuber:
>>> Hey, just think I might find an asteriod....just hope it's not _the
>>> asteroid_.
>> Does this telescope record its image on film/ccd or an eyeball?
>> Well right now I've got a 35 mm cannon hooked up to it.
It'll take a bigger cannon than that to take out _the asteroid_ !!! : )
Hopefully you have in mind to do a web page on this project?
On 03 Jan 1999 18:14:50 -0500, David Steuber <·····@david-steuber.com>
wrote:
> Does this telescope record its image on film/ccd or an eyeball? The
> earth's rotation is constant, so you can pre-calculate the rate that
This may be true for a telescope with an equatorial mounting (i.e. one with
an axis parallel to the Earth's rotation axis; most of the instruments
built before the eighties installed at major observatories are like that),
but not for one with an altazimuthal mounting (i.e. like a theodolite or a
camera tripod). Rusty's dobsonian telescope has the latter.
> the steppers need to move. You will also need to work out the drift
> in the clock so that you can keep a star fixed in the field of view.
Besides that, if the dobson is used for photography it probably needs a
third movement, that of the film or CDD detector in the focal plane around
the instrument's optical axis. This compensates for "diurnal libration" (if
I remember the expression correctly). To understand what I'm talking about,
look at the orientation of the gibbous Moon when it rises, reaches its
maximum height above the horizon at South and finally sets.
Paolo
--
Paolo Amoroso <·······@mclink.it>