Hi,<br>The blog[1] Richard mentioned seems to be dealing with matching the stars using their RA and Dec.<br>Even the code mentioned in the last comment of the page seems to be for that.<br>I was looking for a code which matches stars from frame to frame using their pixel coordinates.<br>

The <a href="http://astrometry.net">http://astrometry.net</a> suggested by Wolfgang does what i wanted. <br>But as he suggested, i think i shall write a function in python itself to do that, so that we can use it for general purpose.<br>

I am planning to use the algorithm mentioned by Peter B. Stetson in his &#39;The Techniques of Least squares and stellar Photometry with CCDs&#39;  [2].<br>Thanking you all for suggestions,<br>-cheers<br>Joe<br><br>[2] <a href="http://ned.ipac.caltech.edu/level5/Stetson/Stetson5_2.html">http://ned.ipac.caltech.edu/level5/Stetson/Stetson5_2.html</a><br>

<br><br><div class="gmail_quote">On 14 March 2012 21:49, Richard P Wagner <span dir="ltr">&lt;<a href="mailto:rpwagner@sdsc.edu">rpwagner@sdsc.edu</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

Hi Joe,<br>
<div class="im"><br>
On Mar 14, 2012, at 7:13 AM, Joe Philip Ninan wrote:<br>
<br>
&gt; Hi,<br>
&gt; Is there any python function to cross-identify the stars between different frames and calculate the coefficients of coordinate transformation equations?<br>
&gt; If not, i am planning to implement it by first running daofind using pyraf and then trying to match triangles; starting from brightest stars.<br>
&gt; Is there any better/easier way to do this?<br>
&gt; Thanking you,<br>
&gt; Joe<br>
<br>
</div>I don&#39;t tackle observational data myself, but I know that others work on cross-matching regularly. You might find this AstroPython blog post a useful starting point [1].<br>
<br>
--Rick<br>
<br>
[1] <a href="http://www.astropython.org/blog/2010/4/Question-Cross-matching-in-python" target="_blank">http://www.astropython.org/blog/2010/4/Question-Cross-matching-in-python</a><br>
<div class="im HOEnZb"><br>
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************************************************<br>Joe Philip Ninan    <a href="http://sites.google.com/site/jpninan/" target="_blank">http://sites.google.com/site/jpninan/</a>    <br>Research Scholar        /________________\<br>

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