0.1 HOW-TO: PSF Information 0.1 HOW-TO Obtain PSF Information of Science Images A simple recipe is available to make several plots of SExtractor parameters relevant to the PSF. The recipe is $AWEPIPE/astro/filerecipes/PSF Anistropy.py and is used as follows: -------------------------------------------------------------------------CATEGORY : Health check PURPOSE : Detect PSF Anisotropy FULFILLS : Requirement 554 (Category III) -------------------------------------------------------------------------This recipe makes 5 plots of SExtractor parameters: 1) Bars of length FWHM_IMAGE (times a scale factor) and angle w.r.t. x-axis Theta. Average FWHM_IMAGE and THETA are evaluated per area in a grid of Xpos/Ypos. 2) MAG_ISO vs. FLUX_RADIUS (half-light radius) 3) FWHM_IMAGE vs. THETA (position angle) 4) FWHM_IMAGE vs. Xpos-CRPIX1 5) FWHM_IMAGE vs. Ypos-CRPIX2 -------------------------------------------------------------------------Mandatory inputs : -l : list of input split raw or processed science images Configuration parameters (min - [default] - max) : -s -d : switch to not run SExtractor (if catalogs already exist) : SExtractor detection threshold range: 0.0 - [10.0] - 100.0 -f : maximum FLAG of sources range: 0 - [0] - 255 -m : maximum FLUX_MAX of sources range: 0 - [60000] - 70000 -r : minimum FLUX_RADIUS of sources range: 0.0 - [0.0] - 50.0 -rm : maximum FLUX_RADIUS of sources range: 0.0 - [50.0] - 50.0 Switches : -in : interactive mode (if omitted a postscript file is created) Example of use : awe PSF_Anisotropy.py -l image12345_?.fits [-s] [-d 5.0] [-f 1] 1 0.1 HOW-TO: PSF Information [-m 50000] [-r 2.0] [-rm 5.0] [-in] -------------------------------------------------------------------------Note that the recipe can be used on a single coadded image by giving it as input. Below is an example of an output plot 2 0.1 HOW-TO: PSF Information Figure 1: Example output plot of PSF Anistropy 3