| AHELP for CIAO 4.5 | mkpsfmap |
Context: tools |
Synopsis
Look up the PSF-size for each pixel in an image
Syntax
mkpsfmap infile outfile energy spectrum ecf [psffile] [units] [geompar] [clobber]
Description
mkpsfmap takes an input image and looks up the PSF-size at each pixel in the image. The user supplies the energy and the desired Enclosed Counts Fraction (ECF) value.
Any NULL, NaN or pixels outside the data subspace are set to NaN. This is useful, for instance, to be able to filter the image with the field-of-view file ("ahelp skyfov") so that only pixels which are on the chip will get resolved.
Note that this tool does not take the average aspect dy, dz, and dtheta into account.
Example 1
mkpsfmap acis_img.fits acis_psf.fits 1.4 ecf=0.5
Computes the psf-size for each pixel in the input image at 1.4 keV for a 50% (0.5) enclosed counts fraction
Example 2
mkpsfmap "hrc_img.fits[sky=region(fov.fits)]" psf.fits 0.9 ecf=0.9 units=physical
Computes the 90% (0.9) ECF at 0.9 keV at each pixel in the input. Pixels that fall outside the supplied fov.fits region are set to NaN. The output units are in physical pixel (as opposed to the default which is the psfsize in arcsec).
Example 3
mkpsfmap acis_img.fits acis_psfmap.fits energy=INDEF spectrum=wghts.dat ecf=0.9
When energy=INDEF, the spectrum file is used. The output will be computed at the spectrum energies and weighted by the weights.
Parameters
| name | type | ftype | def | min | max | units | reqd |
|---|---|---|---|---|---|---|---|
| infile | file | input | yes | ||||
| outfile | file | output | yes | ||||
| energy | real | keV | yes | ||||
| spectrum | file | yes | |||||
| ecf | real | 0 | 1 | yes | |||
| psffile | file | input | no | ||||
| units | string | arcsec | no | ||||
| geompar | file | input | no | ||||
| clobber | boolean | no | no |
Detailed Parameter Descriptions
Parameter=infile (file required filetype=input)
Input image
The header must contain the SIM_* and RA/DEC/ROLL_ PNT (or _NOM) keywords.
Parameter=outfile (file required filetype=output)
Output image
The units of the pixel values in the output image are controled by the 'units' parameter. NaN values indicate that the input image was NaN, NULL, or outside of the data subspace.
Parameter=energy (real required units=keV)
Energy of the PSF to lookup in keV.
If the value is set to INDEF, then the spectrum will be use.
Parameter=spectrum (file required)
Spectral weights file
If a spectrum is input (two column file with energy (keV) vs. weights (renormlized to sum(weights)=1) then a spectrally weighted PSF map will be created.
Parameter=ecf (real required min=0 max=1)
The encircled counts fraction (ECF). Value is between 0 and 1 (100%).
Parameter=psffile (file not required filetype=input)
Parameter=units (string not required default=arcsec)
Valid units are "logical", "physical", or "arcsec"
Parameter=geompar (file not required filetype=input)
Parameter=clobber (boolean not required default=no)
Overwrite existing output dataset with same name?
Changes in CIAO 4.5
A spectrally weighted psfmap can now be created. The energy parameter must be set to INDEF and then the spectum file is simply a 2 colum file with energy vs. weight.
Changes in CIAO 4.5
-
Users can now supply a spectrum and the psfmap will be spectrally weighted.
By setting
energy=INDEF
user can then set the spectrum parameter to a file name. The input is the same format as used by mkinstmap and user can use the same make_instmap_weights tool to create it.
Bugs
There are no known bugs for this tool.
See Also
- calibration
- ardlib
- psf
- psf
- tools
- acis_bkgrnd_lookup, acis_fef_lookup, acis_set_ardlib, add_grating_orders, add_grating_spectra, addresp, aprates, asphist, combine_spectra, dither_region, dmarfadd, dmextract, eff2evt, fullgarf, hrc_bkgrnd_lookup, make_instmap_weights, mean_energy_map, mkacisrmf, mkarf, mkexpmap, mkgarf, mkgrmf, mkinstmap, mkrmf, mkwarf, psextract, psf_project_ray, rmfimg, sky2tdet, specextract

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