[AstroPy] Cross-Identification of stars in a collection of images
Erik Tollerud
erik.tollerud at gmail.com
Fri Mar 16 17:42:34 EDT 2012
Another useful resource that's actually build into scipy is the kdtree
module (scipy.spatial.kdtree). It's not astronomy specific, but it's
an efficient way to do nearest-neighbor searches in arbitrary
coordinate spaces. So you can e.g. feed in the ra/dec of objects from
the first image, and then use that to find nearest-neighbor (or nth
nearest neighbor) of the second image. This is generally the way I do
coordinate matching, because it's one of the most efficient spatial
search algorithms out there. (Note that there's also a Cython version
in scipy.spatial.ckdtree... it has the exact same interface, but it's
compiled, so it's something like 10-100x faster, and possibly more
memory-efficient.)
It doesn't do any kind of transformations though - you'd have to
figure that out based on the matches, I suppose.
On Wed, Mar 14, 2012 at 7:13 AM, Joe Philip Ninan <indiajoe at gmail.com> wrote:
> Hi,
> Is there any python function to cross-identify the stars between different
> frames and calculate the coefficients of coordinate transformation
> equations?
> If not, i am planning to implement it by first running daofind using pyraf
> and then trying to match triangles; starting from brightest stars.
> Is there any better/easier way to do this?
> Thanking you,
> Joe
>
> --
> /---------------------------------------------------------------
> "GNU/Linux: because a PC is a terrible thing to waste" - GNU Generation
>
> ************************************************
> Joe Philip Ninan http://sites.google.com/site/jpninan/
> Research Scholar /________________\
> DAA, | Vadakeparambil |
> TIFR, | Pullad P.O. |
> Mumbai-05, India. | Kerala, India |
> Ph: +917738438212 | PIN:689548 |
> ------------------------------\_______________/--------------
>
>
> _______________________________________________
> AstroPy mailing list
> AstroPy at scipy.org
> http://mail.scipy.org/mailman/listinfo/astropy
>
--
Erik Tollerud
More information about the AstroPy
mailing list