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>

gropt 0.9.4 (2021.01.24)                          January 2021                                          GROPT(1)