Aperture Photometry

[Carlos Milovic]

Hi all

Following the same approach as in StarStatistics, I wrote a new class to perform aperture photometry. Basically, it sums all the flux inside a defined radius, with an aproximation algorithm to deal with partially included pixels. Pixel coordinates are assumed to be measured from the top left corner.

The implementation of that class (APhot) is called Aperture. Right now it has a very simple interface, and only process one star. This was intended just as a testing module, so please report about it's behavior.

This class generates two outputs: flux and magnitude.
Since magnitude needs to be calibrated, the process includes a "magnitude bias" parameter, defined as follows:
mag = -2.5*Log(flux) + C
where C is the constant that needs to be defined by the user.

Now, about background sky estimation. I think that the standard method of rings if wildly innacurate, and other ways need to be implemented. So, Ileft that out from this class.



Download links:

Source code:   http://pteam.pixinsight.com/pcldev/aperture/Aperture-src-20100530.zip
Windows 64bits: http://pteam.pixinsight.com/pcldev/aperture/Aperture-pxm-20100530_win_64.zip
Linux 64bits: http://pteam.pixinsight.com/pcldev/aperture/Aperture-pxm-20100530_x11_64.tar.gz
(Will include 32bits releases if asked).

[Nocturnal]

Cool, thanks Carlos!

[NKV]

Hi Carlos, under Win32 is compiled and work without problem.

where C is the constant that needs to be defined by the user.

How?

[Carlos Milovic]

It is the "Magnitude bias" parameter that is asked in the user interface.

BTW, this parameter is calibrated by using well known reference stars. This means, you should measure the magnitude of these stars (compare with catalog), average the error, and use that as the magnitude bias.