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Last modified: 19 November 2019

URL: https://cxc.cfa.harvard.edu/ciao/bugs/reproject_image_grid.html

Bugs: reproject_image_grid


Table of Contents

Caveats

Bugs


Caveats

Setting the pixelsize to a value in arcseconds

If you are setting the reproject_image_grid pixelsize parameter to a value in arcseconds, you have to specify it when the tool is run, not via pset.

A feature in the CIAO parameter interface causes double quotes (") to be converted to single quotes (') when they are written to the parameter file:

unix% pset reproject_image_grid pixelsize='1"' 
unix% pget reproject_image_grid pixelsize
1'

Supplying the pixelsize on the command line when the tool is run ensures that the value will be correctly interpreted as arcsec, e.g.

unix% reproject_image_grid pixelsize='1"' 
Input image file name (@expmaps.lis): 
.. etc. ..

The value is also correctly recorded in the history of the output file:

unix% dmhistory sn1006_expmap.fits reproject_image_grid
reproject_image_grid infile="@list_of_expmaps.lis" outfile="sn1006_expmap.fits"
xsize="2500" ysize="2500" xcenter="225.7" ycenter="-41.9" theta="0" pixelsize="1""  
projection="tan" resolution="1" method="average" coord_sys="world"  
lookupTab="/soft/ciao/data/dmmerge_header_lookup.txt" clobber="yes" verbose="0" 

Bugs

Incorrect results when using -0 Dec in sexagesimal format

reproject_image_grid fails to correct parse the negative sign when working with -0 deg Declination values in sexagesimal format. For example

unix% reporject_image_grid in.img out.img xcenter=10:20:30 ycenter=-0:10:20 coord=world ...

This bug does not affect negative declination values greater than 0 ( -1 to -90) and does not affect values in decimal degrees.

Workaround:

The work around is to convert the coordinates to decimal degrees

unix% prop_precess f j/hms t j/deg p0 eval 10 20 30 -0 10 20 
155.125000    -0.172222
unix% reporject_image_grid in.img out.img xcenter=155.1250 ycenter=-0.172222 coord=world ...

Bugs fixed in CIAO 4.12

The following is a list of bugs that were fixed in the CIAO 4.12 software release.

Output image has incorrect or missing units

The output image(s) do not have the proper units as one would expect to be derived from the input files.