[gnuastro-commits] master 7c398567 36/69: Book: Correct the some parts of the making the PSF

[Mohammad Akhlaghi]

branch: master
commit 7c398567d2ffc76822f72ed04efb5731951f4bcb
Author: Sepideh Eskandarlou <sepideh.eskandarlou@gmail.com>
Commit: Mohammad Akhlaghi <mohammad@akhlaghi.org>

    Book: Correct the some parts of the making the PSF
    
    Until now, in the first part of the book about the making PSF, the stars
    have been selected by 'astquery' from Gaia and then by using 'asttable'
    sort all of stars and just select just 5 brightness of them. And the
    comment in the book was so long.
    
    Now, for selecting the stars in different range of magnitude for making the
    different part of the PSF, we do not use the 'astquery' and 'asttable' for
    selecting the bright stars. I explained that just by using
    'astscript-create-select-stars' we can select stars in the special range of
    magnitude and long commite are shrinked.
    
    Now, some parts have corrected.
---
 doc/gnuastro.texi | 53 +++++++++++++++++++++++------------------------------
 1 file changed, 23 insertions(+), 30 deletions(-)

diff --git a/doc/gnuastro.texi b/doc/gnuastro.texi
index 8572e68b..1b96b07c 100644
--- a/doc/gnuastro.texi
+++ b/doc/gnuastro.texi
@@ -23416,14 +23416,15 @@ The fundamental ideas of the following methodology 
are fully described in Infant
 Here we describe some scripts developed with the aim of constructing an 
empirical PSF, and then, use that PSF for correcting the scattered light.
 
 For constructing the PSF, the basic idea is to consider a bunch of images of 
stars, treat them properly, and finally stack all of them together.
-For doing this, we have the script @file{astscript-psf-create-make-stamp}.
-This script generates the stamp of a specified star using as input an image 
and some parameters.
-Once several stamps have been generated, the PSF can be obtained by stacking 
them.
+For doing this work, first of all, the stars in different range of magnitude 
should be selected.
+For doing this work we have the script 
@file{astscript-psf-create-select-stars}, that based on this script, the 
circular stars with good parallax and less than nine neighbors from an image as 
input are selected.
+Then by using the @file{astscript-psf-create-make-stamp} script, and based on 
the image as input and coordinates of the stars that has been selected in the 
previous step, the stamp of each star is made.
+Now the several stamps have been generated and the PSF can be obtained by 
stacking them.
 
 Sometimes it is necessary to obtain different regions of the same PSF from 
different stars.
 For example, to construct the far wings it is necessary to consider very 
bright stars.
 However, these stars will be saturated in the most inner part, and 
consequently, fainter stars are necessary.
-It is possible to use @file{astscript-psf-create-make-stamp} to obtain two 
different PSFs (core and wings, using sets of stars with different brightness), 
and then, join them to obtain a single and extended PSF.
+By using the @file{astscript-psf-create-select-stars} script the stars in 
different range of magnitude(faint stars for core and bright stars for wing of 
the PSF) are selected. Then by using @file{astscript-psf-create-make-stamp} two 
different PSFs are obtained. Finally, join them to obtain a single and extended 
PSF.
 To do that, we have the script @file{astscript-psf-create-junction}.
 This script merges two different PSFs at a given radius and some other 
parameters.
 
@@ -23457,19 +23458,24 @@ IMAGE=image.fits
 NORMRADII_INNER=20
 NORMRADII_OUTER=30
 
+# The range of magnitude for making inner part of the PSF.
+MINIMUM_MAGNITUDE=3
+MAXIMUM_MAGNITUDE=5
+
+# The output of the astsegment for input image.
+SEGMENT=segment.fits
+
 
 ## Obtain a catalog of stars
 ## -------------------------
 
-## Download a Gaia catalog that overlap with the input image.
-astquery gaia --dataset=edr3 --overlapwith=$IMAGE \
-              -cra,dec,phot_bp_mean_mag --output=gaia.fits
+# Select the stars in the range of magnitue between
+# MINIMUM_MAGNITUDE to  MAXIMUM_MAGNITUDE, that
+# overlap with the input image.
+astscript-psf-create-select-stars $IMAGE --hdu=1 \
+    --segmented=SEGMENT --min=MINIMUM_MAGNITUDE \
+    --max=MAXIMUM_MAGNITUDE --output=catalog.fits
 
-## Sort by brightness and select just NSTARS stars.
-## These stars are going to be used for constructing the PSF.
-## At the end, they are also modeled and subtracted.
-asttable gaia.fits --sort=phot_bp_mean_mag \
-                   --head=$NSTARS --output=catalog.fits
 
 
 ## Construct the PSF
@@ -23565,28 +23571,15 @@ $ astscript-psf-create-select-stars [OPTION...] 
FITS-file
 Examples:
 
 @example
-## Use the input image 'image.fits' and based on that
-## select stars from an astquery '--dataset', with a
-## '--field' magnitude value between '--min' and
-## '--max'. Additionaly, with the segmented file
-## '--segmented', only stars which match clumps within a
-## given '--matchaperturedeg', and with an axis ratio
-## '--minaxisrario' are selected.
+## From input image select the stars in the range of
+## magnitude between '--min' and '--max'.
 $ astscript-psf-create-select-stars image.fits --hdu=1 \
     --segmented=segment.fits --min=5 --max=7 \
     --output=selected-gaiastars.fits
 
-## If input image is simulated image and catalog of stars
-## are not in the Gaia at all. In this case, Instead of
-## Gaia data base gives the '--catalog' of stars. Which
-## this catalog contain three column. The name of the
-## first column should be 'ra' the second column should be
-## 'dec' and third column should be 'photo-g-mean-mag'.
-## based on the this catalog the stars in the range of
-## magnitude between '--min' to '--max' are selected
-## and then with segmented file '--segmented', only stars
-## which match clumps within a given '--matchaperturedeg',
-## and with an axis ratio '--minaxisratio' are seleted.
+## If the stars does not exist in the Gaia, based on the
+## prepare catalog select the stars in the range of
+## magnitude between `--min` and `--max`.
 $ astscript-psf-creat-select-stars image.fits --hdu=1 \
     --catalog=starscatalog.fits --segmented=segment.fits \
     --min=5 --max=7 --output=selected-simulatestars.fits