NAME

       gropt - performing ray tracing computation of optical systems

SYNOPSIS

       gropt [options] <input> [...] [-o <output>]

DESCRIPTION

       The  purpose  of  the  task `gropt` is to perform various computations in the framework of
       geometrical optics. The main input of the  task  is  a  descriptor  file  quantifying  the
       various  optical  elements  (lenses,  mirrors,  aperture  stops,  etc.  and the respective
       materials) as well as the alignment geometry  of  these  pieces.  The  output  of  `gropt`
       includes  well-known  products of optical analysis such as ray transfer matrices, analysis
       for multiple wavelengths, ray diagrams, 3D models for visualization, spot diagrams, models
       for  spatially  quantized  point-spread  functions,  plate  solutions  and vignetting. The
       underlying ray trace library (see ./src/optcalc.[ch]) is  also  included  in  the  program
       `firandom`  in  order  to  generate both precise and accurate simulated images that can be
       acquired with the given optical setup.

OPTIONS

   General options:
       -h, --help
              Give general summary about the command line options.

       --long-help, --help-long
              Gives a detailed list of command line options.

       --wiki-help, --help-wiki, --mediawiki-help, --help-mediawiki
              Gives a detailed list of command line options in Mediawiki format.

       --version, --version-short, --short-version
              Give some version information about the program.

       <input>, -i <input>, --input <input>
              Name of the input file describing the optical system. Note that all of  the  length
              dimensions,  including  offsets,  curvatures,  curvature  radii  and  higher  order
              aspherical constants are needed to be defined in the units of millimeters.  Reading
              from standard input can be forced using a single dash "-" as input file name.

   Testing and benchmarking:
       --speed-test <time/seconds>
              In  this mode, gropt runs a speed test to figure out the number of rays that can be
              traced during the given interval of time. Note  that  this  speed  depends  on  the
              optical system itself, so one should specify a valid input (see -i, --input).

   Common options for the various analysis modes:
       -l, --lambda, --wavelength <wavelength/microns>
              The wavelength (in microns) of the ray set of the actual analysis.

       -f, --focus <focal-plane-position>
              The  position  of  the  focal  plane. It overrides the "focal" keyword in the input
              optical system description (see -i, --input for more).

       -x, --scale <pixel-scale>
              The pixel scale (i.e. the pixel size), also in millimeters.

       -a, --angle <incident-angle/radians>|<normal_x>,<normal_y>
              The incident angle of the incoming parallel rays. If a single parameter  is  given,
              then  it  is  going to be interpreted as an angle in radians. If two parameters are
              given after -a or --angle then these are treated as the x and y components  of  the
              ray  normal  vector.  By  conventions,  a  single paramater of "a" is equivalent to
              "0,sin(a)".

   Spot diagram analysis:
       -s, --spot-aperture <radius>[,<number-of-rings>[,<position>]]
              The radius, the number of the rings and the offset of spot  aperture.  If  omitted,
              the  number  of the rings is going to be one and the offset of the spot aperture is
              going to be zero. Note that the option -o, --output or --output-spot is  needed  to
              be specified in order to perform a spot diagram analysis.

       -o, --output, --output-spot <spot-diagram-output>
              The name of the file to which the spot diagram output is intended to be written. To
              write the output to the standard output, use a dash (-) as a file  name.  To  write
              the output to the file named as a dash, use -o ./- or something equivalent.

   Ray transfer matrix analysis:
       -t, --transfer
              Perform  a  ray  transfer  matrix analysis. The results (namely, the computed focal
              plane offset and the effective focal length) are written to the standard output.

   Exporting geometry:
       -d, --output-scad <openscad-file>
              Exports the geometry of the input optical setup to an OpenSCAD file. This 3D  model
              of  the  setup  can  then be viewed by running `openscad` whose input is the output
              this process.

       -e, --output-eps <encapsulated-postscript-file>
              Exports the geometry of the input optical setup to an encapsulated PostScript file.
              This  PostScript image can be considered as a planar diagram of the lens system. If
              -s or --spot-aperture is defined,  then  rays  are  also  drawn  according  to  the
              specifications following these command-line switches.

   Determination of point-spread function:
       -z, --psf-half-size <half-size>
              The  half  size  of  the  output  point-spread  function. If this parameter is, for
              example, 3, then the resolution of the output point-spread function will be 7x7. In
              general,  if  the parameter is H, then the output point-spread function will have a
              resolution  of  (2H+1)x(2H+1).  Note  that  the  pixel  scale  of   this   computed
              point-spread function is defined by -x or --scale.

REPORTING BUGS

       Report bugs to <apal@szofi.net>, see also https://fitsh.net/.

COPYRIGHT

       Copyright © 1996, 2002, 2004-2008, 2010-2016, 2018-2020; Pal, Andras <apal@szofi.net>