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author | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
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committer | Joe Hunkeler <jhunkeler@gmail.com> | 2015-08-11 16:51:37 -0400 |
commit | 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 (patch) | |
tree | 4464880c571602d54f6ae114729bf62a89518057 /noao/artdata/doc/mk2dspec.hlp | |
download | iraf-osx-40e5a5811c6ffce9b0974e93cdd927cbcf60c157.tar.gz |
Repatch (from linux) of OSX IRAF
Diffstat (limited to 'noao/artdata/doc/mk2dspec.hlp')
-rw-r--r-- | noao/artdata/doc/mk2dspec.hlp | 207 |
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diff --git a/noao/artdata/doc/mk2dspec.hlp b/noao/artdata/doc/mk2dspec.hlp new file mode 100644 index 00000000..44336400 --- /dev/null +++ b/noao/artdata/doc/mk2dspec.hlp @@ -0,0 +1,207 @@ +.help mk2dspec Aug90 noao.artdata +.ih +NAME +mk2dspec -- Make/add 2D spectra using 1D spectra templates +.ih +USAGE +mk2dspec input +.ih +PARAMETERS +.ls input +Spectra to create or modify. +.le +.ls output = "" +Output spectra when modifying input spectra. If no output spectra are +given then existing spectra in the input list are modified directly. +If an output list is given then it must match in number the input list. +.le +.ls models = "" +List of model parameter files. If the list of model files is shorter than the +list of input images then the last model file is reused. The model +parameter files contain lines giving one dimensional spectrum template +name, intensity scale, type of cross dispersion profile, profile +width in the center line, change of width per line, profile position +in the center line, and change of position per line (see the DESCRIPTION +section). +.le +.ls comments = yes +Include comments recording task parameters in the image header? +.le + +WHEN CREATING NEW SPECTRA +.ls title = "" +Image title to be given to the spectra. Maximum of 79 characters. +.le +.ls ncols = 100, nlines = 512 +Number of columns and lines. +.le +.ls header = "artdata$stdheader.dat" +Image or header keyword data file. If an image is given then the image header +is copied. If a file is given then the FITS format cards are copied. +This only applies to new images. The data file consists of lines +in FITS format with leading whitespace ignored. A FITS card must begin +with an uppercase/numeric keyword. Lines not beginning with a FITS +keyword such as comments or lower case are ignored. The user keyword +output of \fBimheader\fR is an acceptable data file. See \fBmkheader\fR +for further information. +.le +.ih +DESCRIPTION +This task creates or modifies two dimensional spectra by taking one +dimensional spectra, convolving them with a spatial profile across the +dispersion, and adding them into two dimensional images. The one +dimensional spectra may be real data or artificial data created with +the task \fBmk1dspec\fR. No noise is included but may be added with +the task \fBmknoise\fR. The spatial profile is fully subsampled and +may vary in width and position along the dispersion axis. The spatial +axis is along the first dimension and the dispersion is along the +second dimension. + +For new images a set of header keywords may be added by specifying an +image or data file with the \fIheader\fR parameter (see also \fBmkheader\fR). +If a data file is specified lines beginning with FITS keywords are +entered in the image header. Leading whitespace is ignored and any +lines beginning with words having lowercase and nonvalid FITS keyword +characters are ignored. In addition, comments may be added to +the image header recording the model file name and the contents of the +model file. + +The spatial profile models are specified in one or more model parameter +files. These files contain lines giving a one dimensional spectrum template +name, intensity scale, type of cross dispersion profile, profile +width in the center line, change of width per line, profile position +in the center line, and change of position per line. More specifically: + +.ls <template name> +The one dimensional spectrum template is any one dimensional IRAF image. +If the spectrum template length is less than the two dimensional spectrum, +the profile extends only over that number of lines and, if it is longer, +then only the first part of the spectrum is used. +.le +.ls scale +The template spectrum is scaled by this parameter to define the +total flux for the two dimensional profile. +.le +.ls <profile type> +The spatial profiles are identified by two keywords, "gaussian" +or "slit". The profiles are defined by the following formulae, + +.nf + gaussian: I(x) = exp (-ln(2) * (2*(x-xc)/fwhm)**2) + slit: I(x) = exp (-ln(2) * (2*(x-xc)/fwhm)**10) +.fi + +where x is the column coordinate, xc is the profile center, and +fwhm is the full width at half maximum. The "gaussian" profile +is the usual gaussian specified in terms of a FWHM. The "slit" +profile is one which is relatively flat and then rapidly drops +to zero. The profile is normalized to unit integral so that +the total flux across the profile is given by the scaled +1D spectrum flux. +.le +.ls fwhm, dfwhm +The full width at half maximum and derivative with line number. The fwhm is +defined for the middle of the image. The FWHM as a function +of line, l, is, + + fwhm + (l - nlines/2) * dfwhm +.le +.ls center, dcenter +The profile center and derivative with line number. The center is +defined for the middle of the image. The center as a function +of line, l, is, + + center + (l - nlines/2) * dcenter +.le + +The provision for having the spectra tilted relative to the columns is +useful for understanding undersampling effects. However, note that the +spectral lines are not perpendicular to the dispersion but are always +aligned with the image lines. +.ih +EXAMPLES +1. Create an artificial multifiber spectrum: + +.nf + cl> type multifiber.dat + arc 4 gauss 3 0 20 .01 + spec1 .5 gauss 3 0 30 .01 + spec2 .4 gauss 3 0 40 .01 + spec3 .9 gauss 3 0 50 .01 + spec4 .2 gauss 3 0 60 .01 + spec5 .6 gauss 3 0 70 .01 + spec6 1 gauss 3 0 80 .01 + spec7 1 gauss 3 0 90 .01 + cl> mk1dspec arc cont=0 peak=500 nl=30 + cl> mk1dspec spec1 nlines=99 seed=1 + cl> mk1dspec spec2 nlines=80 seed=2 + cl> mk1dspec spec3 nlines=45 seed=3 + cl> mk1dspec spec4 nlines=95 seed=4 + cl> mk1dspec spec5 nlines=66 seed=5 + cl> mk1dspec spec6 nlines=90 seed=6 + cl> mk1dspec spec7 nlines=85 seed=7 + cl> mk2dspec multifiber model=multifiber.dat +.fi + +In this example artificial one dimensional spectra are generated with +\fBmk1dspec\fR. + +2. Create an artificial multislit spectrum: + +.nf + cl> type multislit.dat + arc 10 slit 18 0 120 .01 + sky 2.5 slit 18 0 140 .01 + sky 2.5 slit 18 0 160 .01 + sky 2.5 slit 18 0 180 .01 + sky 2.5 slit 18 0 200 .01 + sky 2.5 slit 18 0 220 .01 + + spec1 .05 gauss 3 0 140 .01 + spec2 .2 gauss 4 0 161 .01 + spec3 .1 gauss 3 0 179 .01 + spec4 .1 gauss 3 0 200 .01 + spec5 .15 gauss 4 0 220 .01 + cl> mk1dspec sky peak=1 nl=100 + cl> mk2dspec multislit model=multislit.dat nc=400 +.fi + +Note how two spectra are overlaid to provide a sky spectrum with a +narrower object spectrum. + +3. Create an artificial long slit spectrum: + +.nf + cl> type longslit.dat + sky 22 slit 160 0 220 .01 + spec5 .05 gauss 3 0 140 .01 + spec1 .05 gauss 3 0 190 .01 + spec4 .5 gauss 3 0 220 .01 + spec2 2 gauss 40 0 220 .01 + spec5 .1 gauss 3 0 240 .01 + spec1 .02 gauss 3 0 290 .01 + cl> mk2dspec longslit model=longslit.dat nc=400 +.fi + +Note how objects are overlaid on a long slit sky spectrum. The width +of the spec2 spectrum is wider simulating a galaxy spectrum. + +4. To include noise use the task \fBmknoise\fR: + +.nf + cl> mk2dspec longslit model=longslit.dat nc=400 + cl> mknoise longslit rdnoise=10 gain=2 poisson+ ncos=100 +.fi + +5. Use a real long slit spectrum and add an object with an artificial spectrum: + +.nf + cl> mk1dspec artspec1d nlines=50 + cl> mk2dspec ls005 out=ls005new model=STDIN + artspec1d 1 gauss 5 0 125 0 + [EOF] +.fi +.ih +SEE ALSO +mk1dspec, mknoise, mkheader +.endhelp |