`wrecon' generates a source list from the information output by
wtransform at each wavelet scale [correlation maxima tables,
normalized (flat-field) background images (with errors), and
correlation images]. Each correlation maximum is tested to
see if it represents an independent, new, source, or a source
seen at other scales. For each source, a cell is computed
that contains the majority of the source flux, and within that
cell, source properties (location, count flux, etc.) are
computed.
Note: As a stand-alone tool, `wrecon' is only intended for use by
those with a thorough understanding of the wavelet detection
process. Most users should use the `wavdetect' script.
Running `wtransform' followed by `wrecon' provides for more
flexibility (e.g. different sized Mexican Hats in the x and y
directions); running `wrecon' multiple times on the same output
files of `wtransfom' permits experimentation with the choice
of flux scales and other parameters without redoing `wtransform'.
For a more complete description of the theory and operation
of wavdetect, please see the wavdetect sections of the
CIAO Detect Manual.
wrecon pleiades.fits pleiades_sources.fits pleiades_scell.fits
pleiades_img.fits correl=pleiades_correl_stk.lis
nbkg=pleiades_nbkg_stk.lis srclist=pleiades_src_stk.lis
defnbkgfile=pleiades_nbkg.fits fluxfile=pleiades_flux_stk.lis
xscales="1 2 4 8 16" yscales="1 2 4 8 16" fluxscales="1 3 5"
Read a primary image from "pleiades.fits", a list of candidate
source files from "pleiades_sources.lis", a list of correlation
images from "pleiades_correl_stk.lis", and list of normalized
background images from "pleiades_nbkg_stk.lis". All these must
have come from a previous run of wtransform. Generate a source
list "pleiades_sources.fits", a source cell image "source_cell.fits"
a source image "image.fits", a normalized background image
"background.fits", and a set of flux image files, which will be
listed in "pleiades_flux_stk.lis". Fluxes will only be generated
for the first, thrid, and fifth x/y scale pairs. Note that the
quotes around the x/y scale lists and the flux scale list are
required.
For other wavdetect examples, please see the CIAO Science
Thread
"Detecting Sources in Imaging Observations - Using wavdetect".
The input data set. If not a FITS primary image, must include
the extension (eg: "foo.fits[EVENTS]").
Parameter=sourcefile (file required filetype=output autoname=yes)
File containing the output source list.
If auto-naming is used (sourcefile=.), the output file will have the
suffix "_src".
Parameter=scellfile (file required filetype=output autoname=yes)
File name of the image showing the source cells, which delimit
the image pixels which are used to estimate source properties
(e.g. count rate).
If auto-naming is used (scellfile=.), the output file will have the
suffix "_scell".
Parameter=imagefile (file required filetype=output autoname=yes)
Output file containing the reconstructed, noise-free source
image.
If auto-naming is used (imagefile=.), the output file will have the
suffix "_image".
File for ASCII region output.
If auto-naming is used (regfile=.), the output file will have the
suffix "_reg". NB: not currently operational.
If "yes", existing outputs will be overwritten.
Size, in sigmas, to make the elliptical source regions.
ellsigma is a multiplicative factor applied to sigma, the standard deviation
of the distribution, to scale the major and minor axes of the ellipses for each
source. ellsigma affects both the outfile and the ASCII region file (regfile).
This feature is included so that the graphics overlay will be more visible
and under the user's control. Often a value greater than 3 is helpful.
File name of stack (list) of candidate source correlation
maxima, output at each scale by wtransform.
File name of stack (list) of correlation images from each
wavelet scale.
Parameter=nbkg (file required filetype=input)
File name of stack (list) of normalized (i.e. flat-field)
background images computed at each wavelet scale by
`wtransform'. These images must include error images.
Parameter=bkginput (file not required filetype=input default=)
Pre-determined background input image.
Use a previously computed background in the specified file in
place of constructing a new default normalized background.
When using bkginput, enter "none" for the default normalized
background file.
If yes, use background error in file bkginput[2].
Default normalized background file.
`wrecon' makes one normalized background estimate from the
stack of per-scale normalized backgrounds produced by
`wtransform'. It writes this computed background to this
file. If autonaming is used (defnbkgfile=.), the file name will have the
suffix "_nbkg".
File name of stack (list) of flux images computed at each
user-defined scale pair. (See fluxscales.)
Leave blank. This parameter controls extra text to insert in
output filenames. for internal use only.
The input of xscales must be identical to that used in `wtransform'.
The input of yscales must be identical to that used in `wtransform'.
Which of the x, y scales should be used for flux calculations.
Nominate (with integers) the locations in the x, y scales
ordered lists which should be used for flux calculations.
This list, like the scales input, uses spaces for separators.
Parameter=expfile (file not required filetype=input)
Image of exposure time for dataset.
Parameter=exptime (real default=0 min= units=seconds)
Time of the exposure, in seconds. If set to zero, the program
estimates the exposure time from the exposure map.
Relative exposure threshold.
For each pixel, a relative exposure is calculated (pixel
exposure time over detector livetime). If this relative
exposure is less than the parameter expthresh (typically
0.1-0.2), then the pixel in question is not analyzed.
Only affects wrecon if the expthresh specified for it if
higher than that specified for wtransform; in this case, a
subset of correlation maxima identified by wtransform will
not be examined. (This can come into play if, for instance,
one wishes to only make a source list for highly exposed
areas after running wtransform on the whole image.)
Parameter=bkgtime (real default=0 min= units=seconds)
Livetime of predetermined background (in seconds).
This parameter is only used *if* the user has provided a
normalized background image. A value of 0 means use the
exposure time as the background time.
Offset of x-axis for the calculation of the off-axis angle.
By default (when both offsets are set to INDEF), wrecon
calculates the off-axis angle using the nominal pointing of
the data file as the origin. Users may change this behavior
by specifying offsets to any numerical values; the offsets
provide the location of the optical axis with respect to the
center of the data file.
Offset of y-axis for the calculation of the off-axis angle.
Energy, in keV, at which the PSF size should be computed.
Percentage of encircled energy, expressed as a fraction of
1.0, which the PSF size (see "eband") should contain.
Percentage of encircled energy, expressed as a fraction of
1.0, which the PSF size (see "eband") should contain.
Suggested values: .393 (one-sigma percentage threshold for a
two-dimensional Gaussian), or 0.500. The efficiency of the
algorithm is reduced if this fraction is made too high (say,
0.900) or too low.
The encircled energy fraction of the PSF is used
to estimate the PSF size, in pixels, at the
location of each detected source. The default
value (0.393) is the one-sigma integrated volume
of a normalized two- dimensional Gaussian, thus
the estimated PSF size should be approximately one
sigma. The PSF size is used only to select a flux
image; a source cell is computed using this image,
and source properties are estimated using the data
within the computed cell. NB: Unlike celldetect,
the PSF library and eenergy have no effect on the
detection process in wavdetect.
If the value of eenergy is set too high, there is
the risk that the computed source cell will
contain more than one source, rendering source
property estimates moot. On the other hand, if
the value is set too low, then the computed cell
may be too small and contain only a fraction of
the source counts.
Parameter=psftable (file required filetype=ARD default=)
FITS file of psf information. File is included with the
release. The user may not specify "CALDB" for this parameter.
Special mode used to rendezvous a debugger with wrecon. Leave
as "no".
If set to "no", log information will go to stdout. If set to
"yes", file "wrecon.log" will be created.
Level of log output. 0=none 5=highest.
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