Hi Bill,

As usual you have come up with the goods! Well done.
I am interested in the interface you suggest.
Not certain how to go about it though.

Thanks again.. brilliant work.

Best Regards

Alan

Alan Cahill
Abbeydale Observatory,
Gloucester U.K.
MPC Code J94
http://www.mountabbeydale.pwp.blueyonder.co.uk/

--- In guide-user@yahoogroups.com, Bill J Gray <pluto@p...> wrote:
> Hi Alan,
>
> There's a way of getting the grid spacing you're looking for,
> but it may not be quite as helpful as you might like.
>
> Edit the file 'strings.dat' in Notepad or the text editor of
> your choice. Look down at line 50, and you'll see
>
> 20' 1m
>
> Remembering that, at the celestial equator, 1m in RA is 15' in
> actual angular distance, you change that line to read
>
> 12' 1.1333m
>
> (17/15 = 1.1333m). Save the file, run Guide, and you'll see
> those entries in the 'grids' menu. Select those radio buttons,
> and you'll have grids spaced 17' in RA and 12' in dec... at the
> equator.
>
> Move away from the celestial equator, and the RA spacing will
> be (17 * cos( declination)) arcminutes. One way around this would
be
> to look at the object in question, divide 1.13333m by the cosine
> of its declination, and use that value instead.
>
> All this would still leave you with the grids centered on 12'
> intervals in dec and 17' in RA, and you might wish to lay out a
> pattern centered on some other point. I'll toss out the following
> possible interfaces for comments:
>
> (1) You start editing a new overlay, and set up the CCD frame
> the way you want it for the first image. Then you click some button
> to tell Guide, "Add a CCD frame at the currently selected position
> and angle to the overlay." Move the CCD frame to the next desired
> location, and repeat.
>
> (2) A special "show mosaic" tool: you center the CCD frame
> _once_, then tell Guide: "Add a mosaic of frames extending
> two frames to the left and right, two frames above, and three
> frames below." Guide creates the corresponding 5x6 grid of
> CCD frames. You'd also need to be able to specify, for example,
> that the frames should have a 10% overlap.
>
> The frames would still go into an overlay, so you could click
> on each, change colors, add text, delete some that extended
> into areas in which you weren't interested, and so on... all
> of the currently-available overlay capabilities.
>
> (1), at least, wouldn't be too difficult. (2) would be
> quite a bit trickier, but still not impossible.
>
> Oh, yes... quite independently of all this, the ability to
> just tell Guide to make grids of an arbitrarily specified spacing
> would be potentially useful. This one is suggested occasionally
> by those attempting to make "Uranometria clones". The 1-degree
> square (at the equator) grid spacing isn't available in Guide,
> so they have to use the trick mentioned at the top of this post
> to get a 4m spacing in RA.
>
> -- Bill