Unimap

Hi larry, Yes I have looked into N body solutions too, still have the pain in my head from it! I have a good book here 'Methods of Orbit Determination - Boulet' It's tough reading, but it descibes some elegant algorithms for n body solutions. However if one is just looking to derive astrometric positions from an image, there is no need for any orbit solutions at all. Just an accurate astrometic position from the image.

Anyway, nice job, look forward to seeing your finished work.

Dave.

Thanks Dave!

I was thinking to be looking into n-body "problem" after I will fine tune the multithreading engine and also add an extra punch with gpu processing to it

Larry

Larry - replying to your response in another thread (I should made my comment in this thread).

I believe an amateur should be able to get down to 0.2" rms residuals or at least very close. Only time I've done it I was close to 0.2 in one axis - but nearly 0.5" in the other - I used 20 stars and one was badly mapped in. I was experimenting with fitting a WCS to the FITS header.

Do you intend to allow the user to fit WCS (I believe astrometrica does this)?

I've installed linux and IRAF in a virtual machine on my laptop now - was a bit painful. I want to see just what I can do when using the same tools as the professional crowd.
I've learned stuff enroute that I didn't expect to. I think its going to be a fantastic learning opportunity.

My next step is to see if I can get WCSTools installed and working. Manually fixing up WCS is well doable with basic IRAF but I'd like to make it easier.

Good luck with your project.

Mark

Hi Mark,

Aaa I presume you calculated residuals for the best 20 of them right? Try with all especially were you have field distortion caused by optical equipment/setup – thing which for the average amateur setup will be hard to subtract. Or maybe we are not talking about the same thing here?
However it’s a good idea to display that piece of info as well, I wrote it down.

I also used IRAF and the “bunch” of tools associated and wcstools and as well when though some pain at the time with iraf .. I don’t recall exactly the reason.

Yes, it “supports” WCS in FITS headers … I quote because right now isn’t plugged in the new image i/o engine. The initial image engine I use did not support enough image formats as I wanted so I scraped that for the current library I am using which is better but then again I am not happy because is not very efficient(memory wise) in reading big files so I will probably go in the future for something better and special formats like fits I think I going to implement separately.

Wow, I see people here going serious about this and I was thinking to scrap some parts from my projects as I thought it will make things look too complicated.

Anyway to clarify things a little, I started this project back in 2004 as I realize that more an more people get into astrophotography and I thought that it will be good for them to have a simple to use tool to allow them to explore and learn about the images they are taking. My idea was to just load it in your image which will be solved and then with a few clicks to learn about the stars, nebula, galaxies, distances, etc by automatically fetching information from various sources.
I think that only a few astrophotographers go further then just making nice pictures of the sky and I believe many will go on and learn more about what they shot if there were to be an easy to use tool to allow them to explore and present the information in an easy to digest way. So for a start I am looking more at this software as an educational tool rather then research grade. Next will be to tune down the application to fit the maximum precision possible and have advanced options in it for higher end users – but in this case probably it will be better two release a separate application …
Then again I don’t want to compete with pro/highend tools since these are out there - stuff like iraf/gaia/etc some of them are a bit of nightmare to put together and learn to use them but for someone who wants to play hard is just a matter of time …

Maybe I am wrong the way I thought about it? Any thoughts?

Larry

I like your last post.

Yes - the easier it is for amateurs to visulaise what they are doing and (where there is interest) do metrics the better. I do very little of either at present. I'm very definitely an armchair astronomer. My scope comes out infrequently. I love the maths and concepts and cloudy weather doesn't hinder me too much.

To do serious stuff requires some degree of competancy - and support - and the support is not really there for amateurs. I therefore totally endorse your initiative in providing tools that suport amateurs. However, sometimes it is education that is lacking in the community and not necessarily the tools. Tools (to do almost anything) *are* freely available.

Though having said that, amateurs generally have a lesser stringent operational environment than professionals (there's less that they can do to high precision) and so the software tools do not need to be so comprehensive. It is this area, to some extent, that Astrometrica and, if I may say, your tool, can fill a niche - they empower amateurs without burdening them.

I do feel that going forward amateur WCS fitting should be important. I say this because I believe that it is important that if one amateur astronomer at one place and time says "I have an image and there's a fuzzy" that we can easily compare images/data of observations by others with disparete setups - WCS facilitates this. But we need a means of sharing the data - with appropriate intellectual property restrictions.

Woudn't it be great if an amateur could image an undefined "fuzzy" and be able to trawl a database of images of similar recent field of view for confrmatory support / denial. The time is right for such a service - and WCS will be needed to do this.

I'm ranting, forgive me (I'm an armchair astronomer)

Mark

Hi Mark,

I agree, that’s why I added to my software the online upload/download/browse and a simple(now) search engine ... so the user can share the data(image and astrometry data) directly from within the tool.
Well only the basics for this are implemented and I am holding the astrometric data in a mysql database (so I though will be best to access/search it easier/faster with quries rather then in the header of the fits) … but I can do both no problem (In any case I use WCS standard)… anyway this and everything else is up for debate. I’m open for any suggestions. Ahh … talking of standards … I hope someone out there will think to create a standard for catalogs because believe me it was a real pain to write code to import over 50 different catalogs all in different exotics formats – and there are thousands of catalogs with all sort of information – it will be some to put all this together …

I was thinking of something else the amateur could do … helping revise catalogs. The big ones like usno b1.0 as you know are generated by means of automated plate solving and prove to be inaccurate in some cases. And here you need the human factor and I believe a distributed project like galaxyzoo only little bit more complex could help build better catalogs. And if you ask yourself why anyone will do such a boring task – well you can make this look like a game of some sort and then the competition spirit will kick in. well .. is late and I am rambling …

Larry