epsf Generator

This script generates an ePSF (effective Point Spread Function) from a FITS image by detecting stars, extracting cutouts, and building a PSF model. The output is saved as a FITS file.

What is ePSF?

Basically, the ePSF is the true PSF that you’d measure from actual images.

Code

You can simply download code here.

Usage

To run the script, use the following command:

1epsf_generator [-h] -i IMAGE [-n NUMBER] [-f FWHM] [-s SIZE] -o OUTPUT

Required Arguments

-i or --image: path to FITS image

-o or --output: path to output ePSF FITS file

Optional Arguments

-n or --number: maximum number of stars to use for ePSF model (default is 100)

-f or --fwhm: FWHM (full-width at half-maximum) of stars in pixels (default is 5.0)

-s or --size: size of cutout in pixels around detected stars (default is 25)

-h or --help: show help message and exit

Example

Create an ePSF from an input FITS image and save it as a FITS file:

1epsf_generator -i input.fits -o output.fits

This will generate an ePSF from the input.fits image with default parameters and save it as output.fits.