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bluescope
28-04-2009, 01:10 PM
Hi Everyone

Are there any free " pointing " programs out there like MaxPoint and TPoint ?

PM me if you would like to be discreet :whistle: there are guidelines on this forum that I don't wish to abuse.

Thanks !

:thumbsup:

Terry B
28-04-2009, 02:54 PM
Audela has a pointing routine and it is free
http://www.audela.org/english_audela.php

bluescope
28-04-2009, 03:39 PM
Thanks Terry ... looks like a very diverse and interesting piece of software ... downloading as I type.

:thumbsup:

Bassnut
28-04-2009, 06:38 PM
umm, I dont think thats what your after, its for remote automated control/capture.

Pointing software plate solves and needs a monster star database.

Terry, do you mean point to a location in the sky, or does it plate solve ?, I cant find that feature on the link.

jase
28-04-2009, 08:03 PM
hmmm...free? Thats a tall order... You could give Elbrus a go. Never used it, but have heard reasonable feedback - http://www.astrosurf.com/pulgar/elbrus/elbrusin.htm

More commercial options are;
CCDSoft coupled with TheSky
MaximDL coupled with Pinpoint

If you specifically detail what you're trying to achieve, then it will be possible to point you in the right direction (pun intended). ;)

Cheers

jase
28-04-2009, 08:49 PM
...and yes, as Fred points out...any form of plate solving requires a database (aka catalogue) to check against. That is, the matching of star patterns in your image against a known (and accurate) astrometric source.

You can pull down many of the star catalogue online. They're big (understatement!). For general astrophoto work, you can get by with the GSC (Hubble's guide star catalogue). Its gone through a few accuracy revisions, thus known as GSC-ACT (25 million stars - 1.2 in size). Even the original 1.1 is good. From my experiences, GSC works well for wide field plate solves. Not so good (reliability problems) as the field gets narrow i.e. longer focal lengths and/or smaller ccd arrays. If this is encountered, go with the USNO-A2.0 catalogue (526 million stars - 6.3Gb in size). If I recall correctly, USNO-A2.0 will resolve stars down to mag 19 and is perhaps one of the more accurate catalogues around for astrometric studies. That said, they're constantly improving it.

You only need to look at the GSC II to realise these improvements. It now contains 998 million stars and is 80Gb+ in size. Totally overkill to point a humble imaging rig at an extended object to ensure its centered!

Here you go - http://tdc-www.harvard.edu/catalogs/

Terry B
29-04-2009, 09:43 AM
The pointing routine in Audela is pretty simple. It doesn't plate solve. You connect your scope via ASCOM or what ever you want and start the pointing routine. the scope needs to be aligned first. It slews to a named bright star. You centre that star in the centre of the field. This is best done by taking an image and using crosshairs but could be used visually. When it is centered you slew to the next star etc. It does this for 6 stars across the sky and then produces a report telling you how much flex etc there is.
As for "elbrus".
I use this all the time. It is brilliant with EQMOD.
I start the scope as usual and slew to anywhere in the sky. I take a 5 sec image of the field and send it to elbrus. As long as it is within 5 degrees of being correct and I haven't changed the orientation of my camera it finds the correct poining of the scope. I then let elbrus synch tto scope thus correcting the pointing. My startup poining is usually within 10arcmins so it just refines the pointing. It also adds the field centre data to the fits header of the image making analysis for photometry and astronomy much easier.

bluescope
29-04-2009, 08:49 PM
Thanks guys ... I've downloaded Elbrus as well to have a look.

:thumbsup: