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diff --git a/noao/obsutil/src/doc/kpnofocus.hlp b/noao/obsutil/src/doc/kpnofocus.hlp new file mode 100644 index 00000000..176a8fe7 --- /dev/null +++ b/noao/obsutil/src/doc/kpnofocus.hlp @@ -0,0 +1,214 @@ +.help kpnofocus Mar96 noao.obsutil +.ih +NAME +kpnofocus -- Determine the best focus from KPNO focus images +.ih +USAGE +kpnofocus images +.ih +PARAMETERS +.ls images +List of focus images. +.le +.ls frame = 1 +The image display is checked to see if the image is already in one of +the display frames. If it is not the \fBdisplay\fR task is called to +display the image in the frame specified by the \fBframe\fR parameter. All +other display parameters are taken from the current settings of the task. +This option requires that the image display be active. +.le + +.ls level = 0.5 +The parameter used to quantify an object image size is the radius from the +image center enclosing the fraction of the total flux given by this +parameter. If the value is greater than 1 it is treated as a percentage. +.le +.ls size = "FWHM" (Radius|FWHM|GFWHM|MFWHM) +There are four ways the PSF size may be shown in graphs and given in +the output. These are: + +.nf + Radius - the radius enclosing the specified fraction of the flux + FWHM - a direct FWHM from the measured radial profile + GFWHM - the FWHM of the best fit Gaussian profile + MFWHM - the FWHM of the best fit Moffat profile +.fi + +The labels in the graphs and output will be the value of this parameter +to distinguish the different types of size measurements. +.le +.ls beta = INDEF +For the Moffat profile fit (size = MFWHM) the exponent parameter may +be fixed at a specified value or left free to be determined from the +fit. The exponent parameter is determined by the fit if \fIbeta\fR +task parameter is INDEF. +.le +.ls scale = 1. +Pixel scale in user units per pixel. Usually the value is 1 to measure +sizes in pixels or the image pixel scale in arc seconds per pixel. +.le +.ls radius = 5., iterations = 2 +Measurement radius in pixels and number of iterations on the radius. The +enclosed flux profile is measured out to this radius. This radius may be +adjusted if the \fIiteration\fR parameter is greater than 1. In that case +after each iteration a new radius is computed from the previous FWHM +estimate to be the radius the equivalent gaussian enclosing 99.5% of the +light. The purpose of this is so that if the initial PSF size of the image +need not be known. However, the radius should then be larger than true +image size since the iterations best converge to smaller values. +.le +.ls sbuffer = 5., swidth = 5. +Sky buffer and sky width in pixels. The buffer is added to the specified +measurement \fIradius\fR to define the inner radius for a circular sky +aperture. The sky width is the width of the circular sky aperture. +.le +.ls saturation=INDEF, ignore_sat=no +Data values (prior to sky subtraction) to be considered saturated within +measurement radius. A value of INDEF treats all pixels as unsaturated. If +a measurement has saturated pixels there are two actions. If +\fIignore_sat\fR=no then a warning is given but the measurement is saved +for use. The object will also be indicated as saturated in the output +log. If \fIignore_sat\fR=yes then a warning is given and the object is +discarded as if it was not measured. In a focus sequence only the +saturated objects are discarded and not the whole sequence. +.le +.ls logfile = "logfile" +File in which to record the final results. If no log file is desired a +null string may be specified. +.le +.ih +CURSOR COMMANDS +When selecting objects with the image cursor the following commands are +available. + +.nf +? Page cursor command summary +g Measure object and graph the results. +m Measure object. +q Quit object marking and go to next image. + At the end of all images go to analysis of all measurements. + +:show Show current results. +.fi + +When in the interactive graphics the following cursor commands are available. +All plots may not be available depending on the number of focus values and +the number of stars. + +.nf +? Page cursor command summary +a Spatial plot at a single focus +b Spatial plot of best focus values +d Delete star nearest to cursor +e Enclosed flux for stars at one focus and one star at all focus +f Size and ellipticity vs focus for all data +i Information about point nearest the cursor +m Size and ellipticity vs relative magnitude at one focus +n Normalize enclosed flux at x cursor position +o Offset enclosed flux to by adjusting background +p Radial profiles for stars at one focus and one star at all focus +q Quit +r Redraw +s Toggle magnitude symbols in spatial plots +t Size and ellipticity vs radius from field center at one focus +u Undelete all deleted points +x Delete nearest point, star, or focus (selected by query) +z Zoom to a single measurement +<space> Step through different focus or stars in current plot type + + +:beta <val> Beta parameter for Moffat fits +:level <val> Level at which the size parameter is evaluated +:overplot <y|n> Overplot the profiles from the narrowest profile? +:radius <val> Change profile radius +:show <file> Page all information for the current set of objects +:size <type> Size type (Radius|FWHM) +:scale <val> Pixel scale for size values +:xcenter <val> X field center for radius from field center plots +:ycenter <val> Y field center for radius from field center plots + +The profile radius may not exceed the initial value set by the task +parameter. +.fi +.ih +DESCRIPTION +This task is a script based on the task \fBstarfocus\fR. The details +of the algorithms and display modes are given in the help for that +task. The purpose of \fBkpnofocus\fR is to provide a simpler task +with fewer parameters because the format of the multiple exposure +images is given by header keywords. + +As a summary of the algorithm, the center of each star image is +found using centroids, a background is determined from the mode +of a sky annulus, and the enclosed flux profile is measured. The +PSF width is then the radius enclose a specified fraction of the +flux. Alternatively a direct FWHM from the radial intensity profile, +a FWHM for a Moffat profile fit to the enclosed flux profile, or +a FWHM for a Gaussian profile fit to the enclosed flux profile may be +used. + +If a saturation value is specified then all pixels within the specified +measurement radius are checked for saturation. If any saturated pixels are +found a warning is given and \fIignore_sat\fR parameter may be used ot +ignore the measurement. If not ignored the object will still be indicated +as saturated in the output log. In a focus sequence only the saturated +objects are discarded and not the whole sequence. + +To use this task consists of specifying a focus image name. Multiple +images could be analyzed together but this is uncommon. The task +will then display the image, using the current parameters of the +\fBdisplay\fR task, if the image is not already in the display. +The user then marks the first exposure (the top one) by pointing +the image cursor and typing 'm'. This may be done for more than +one star if desired. After all stars to be used are marked type +'q' to go to the graphical analysis. + +A plot showing the variation of the PSF width and ellipticity with +focus is shown along with a magnitude weighted, parabolic +interpolated estimate for the best focus. One may delete bad points +with the cursor 'd' key. To exit and record the results to +a logfile use the 'q' key. There are many graphical display +options for more sophisticated analysis such as variations with +position. The best thing to do is to try the various keystroke +commands given in the CURSOR section. For details about +the various plots see the \fBstarfocus\fR help. + +The other task parameters allow setting the enclosed flux level, +the object and sky apertures, and the type and scale of the +reported PSF size. The log filename may also be specified. +.ih +EXAMPLES +1. A multiple exposure frame is taken with 7 exposures of a bright +star, each exposure shifted by 30 pixels using the version of the +ICE software which records the focus information in the keywords +FOCSTART, FOCSTEP, FOCNEXPO, and FOCSHIFT. + +.nf +cl> kpnofocus focus1 +<The image is displayed and the image cursor activated> +<The bright star is marked with 'm'> +<Marking is finished with 'q'> +<A graph of FWHM vs focus is shown> +<Exit with 'q'> +NOAO/IRAF IRAFV2.10.3 valdes@puppis Fri 15:48:01 12-Nov-93 + + Image Column Line Mag Focus FWHM Ellip PA SAT + 36inch1 536.63 804.03 0.07 4660. 13.878 0.06 -11 + 535.94 753.28 -0.12 4680. 8.569 0.09 89 + 535.38 703.96 -0.08 4700. 5.164 0.11 -88 + 537.12 655.36 -0.02 4720. 3.050 0.08 -77 + 534.20 604.59 0.00 4740. 4.336 0.11 74 + 534.41 554.99 -0.00 4760. 9.769 0.09 -35 + 534.83 456.08 0.16 4780. 12.569 0.13 -10 + + Best focus of 4722.44 with FWHM (at 50% level) of 3.02 +.fi + +The estimated best focus is between the 4th and 5th focus setting +at a value of 4722.4 and the best focus FWHM is 3.02 pixels. +.ih +SEE ALSO +.nf +imexamine, implot, pprofile, pradprof, psfmeasure, radlist, +radplt, radprof, ranges, specfocus, splot, starfocus +.endhelp |