[AstroPy] Aperture photometry

[Ian Crossfield]

Sergio,

In general, PyRAF is probably your best bet for Python-drive photometry: 
http://www.stsci.edu/resources/software_hardware/pyraf .  This software 
has a long legacy and plenty of users; the learning curve is steep, but 
worth it in the long haul.

If you need to avoid IRAF for some reason, I have some homebrew aperture 
photometry routines on my website; e.g.: 
http://astro.ucla.edu/~ianc/python/phot.html#phot.aperphot 
<http://astro.ucla.edu/%7Eianc/python/phot.html#phot.aperphot>

The documentation isn't terrific, but the calling syntax is:


import phot
observation = phot.aperphot(image,  pos=[x0,y0],  dap=[dap_targ,  dap_skyinner,  dap_skyouter])

Where:
image -- can be the filename of a FITS file, or a numpy array
pos -- x,y pixel coordinates of the target
dap -- _diameters_ of apertures for photometry


Then, e.g., "observation.phot" will give you the photometric measurement 
and "observation.bg" will give you the background level.

But try PyRAF; you'll ultimately be glad you did.

-- 

Ian Crossfield
UCLA Astronomy
KH 3-145J
http://www.astro.ucla.edu/~ianc/




On 4/14/11 10:18 AM, Sergio Pascual wrote:
> Hi
>
> Let's say I have an image as a  numpy array and I want to obtain the
> summed values of the array inside an ellipse inside the image. In
> other words, I wanto to make aperture photometry. Do you know of any
> python astronomy package that implements this. It's a fairly basic
> think, but I haven't found anything.
>
> Regards
>