Encoders/Charon/etc.

Bill J. Gray Jun 30, 2000

Hi folks,

About realigning with encoders... the way this is supposed to work
is as follows. You use Guide "as usual" with the encoders in an
attempt to find an object, and perhaps find that it's not quite on.
You right-click on a nearby star in Guide, click "OK", and then
center that star in the telescope. You then click on "Add Alignment
Star". In theory (and, usually, in practice), you'll find that
your pointing in that part of the sky has become much better.

"...When i start a new session on a second night what is the procedure
to get the encoders and guide7 to start working again ?." It depends.
At one time, I told people that, sadly, you had to completely re-align
each night, because each time the encoder box loses power, you lose
alignment. It turns out that this is not strictly true if your scope is
alt/az or hour angle/dec. In those cases, all you have to do is make
sure that the scope is in the same position each time you start up the
encoders and run through the "Scope Control" dialog.

This works because, when the Scope Control dialog sets the encoder
resolutions, it also initializes them to a consistent value. So you'll
be exactly repeating its configuration from night to night.

That said, I know that Gordon Garradd is trying this stunt and has
found errors of about half a degree. I'm still puzzling over that one.
If anyone else tries this, please let me know.

Mark, about Charon: I'd suggest trying 640x480, 16-color mode.
The reason is that this mode is consistently implemented on all VGA
cards (manufacturers decided to go in all directions at once when it
came to higher-res and color modes.) If it fails, I'd suspect that
DOS is failing to understand the pointing device. I've never heard of
that happening, but it wouldn't surprise me in the least; in fact,
I'm more surprised that it hasn't happened yet.

I've been taking a few steps in the direction of a Windows version
of Charon, mostly in terms of breaking user interface code apart from
everything else (so that "everything else" need not be rewritten every
time the code goes from one OS to another). It's not much of a priority
right now, unfortunately, with Guide 8 running a few months behind my
expectations. (One other benefit of breaking up the Charon code is that
people should be able to make much better use of individual pieces. I've
written a bit about this at

http://www.projectpluto.com/source.htm#charon

And speaking of things on my Web site: those of you curious about
my question about using cheap Webcams for imaging stars should look
here:

http://www.projectpluto.com/webcam.htm

My hope is to use these cameras to make a cheap, but quite good,
star tracking system... it might make encoders just about obsolete
if it works as I think it will.

-- Bill