NAME

       ymira - reconstruct an image from optical interferometric data

SYNOPSIS

       ymira [OPTION]... INPUT... OUTPUT

DESCRIPTION

       MiRA  is  a  software  to reconstruct images from optical interferometric data.  The algorithm performs a
       regularized fit of the data with additional constraints such as  normalization  and  lower  and/or  upper
       bounds.

       INPUT... are the input OI-FITS data file(s) and OUTPUT is the result saved into a FITS file.

OPTIONS

       Options  are  introduced  by  a word prefixed with one or two hyphens (at your convenience).  In case the
       first input file starts with an hyphen, a double hyphen can be used to indicate the end of the options.

       Some options have units.  Angles must be suffixed with mas, milliarcsec, milliarcsecond, milliarcseconds,
       deg,  degree,  degrees,  rad,  radian  or  radians.   Lengths must be suffixed with m, meter, meters, mm,
       millimeter, millimeters, µm, micron, microns, micrometer, micrometers, nm, nanometer or nanometers.

       Some options may take several values which are separated by commas.

   Data Selection
       The following options can be used to select which data to  consider.   If  no  spectral  range  is  given
       (either  with  options  -effwave  and  -effband  or  with  options  -wavemin  and  -wavemax), an image is
       reconstructed from all available wavelengths.

       -target=name
              Specify the name of the astrophysical object.  This option is used to  select  a  specific  target
              from  the  input file(s).  If there is a single target which is identical in all input files, this
              option may be omitted.

       -effwave=length
              Specify the effective wavelength; for example, -effwave=1.6micron.  This is the central wavelength
              of the spectral range to consider.

       -effband=length
              Specify the effective bandwidth; for example, -effband=200nm.  This the full width of the spectral
              range to consider.

       -wavemin=length
              Specify the minimum wavelength; for example, -wavemin=1.5µm.  This the lower bound of the spectral
              range to consider.

       -wavemax=length
              Specify the maximum wavelength; for example, -wavemin=1.7µm.  This the upper bound of the spectral
              range to consider.

   Image Settings
       At least the pixel size (with option -pixelsize) and the image dimensions (with  options  -fov  or  -dim)
       must be specified.

       -pixelsize=angle
              Specify the angular size of pixels.  For example, -pixelsize=0.1mas.

       -fov=angle
              Specify the angular size of the field of view. For example, -fov=20mas.

       -dim=number
              Specify the number of pixels per side of the image.  For example, -dim=200.

       -normalization=value
              Specify the sum of pixels.  A recommended setting is: -normalization=1.

       -min=lower
              Specify the lower bound for the pixel values.  A recommended setting is:-min=0.

       -max=upper
              Specify the upper bound for the pixel values.

   Direct Model
       -xform=name
              Specify  the  method  to  compute the nonequispaced Fourier transform.  Argument name can be nfft,
              exact or fft (the latter value is however not recommended).

   Regularization Settings
       -regul=name
              Specify the name of the regularization method.

       -mu=value(s)
              Specify the global regularization weight(s) µ.  If a single value is given, it will  be  used  for
              all reconstructions.  If two values are given (separated by comas), a different value of µ will be
              used for each reconstructions with the values of µ spaced at equal ratios from start to stop (that
              is, equally spaced logarithmically).

       -tau=value
              Specify the edge preserving threshold.  value must be strictly positive.

       -eta=value(s)
              Specify the gradient scales along dimensions.

       -gamma=angle
              Specify the a priori full half width at half maximum (FWHM).  For example: -gamma=15mas.

   Initial Image
       -initial=name
              Specify the FITS file or method for initial image.

       -seed=value
              Specify the seed for the random generator.

   Reconstruction Strategy
       -bootstrap=count
              Specify the number of bootstrapping iterations.

       -recenter
              Recenter result of bootstrapping iterations.

       -threshold=fraction
              Specify the level for soft-thresholding input image(s).

   Information and Graphics
       -quiet Suppress most messages.

       -verb=count
              Set the verbose level.  Information will be printed every count iteration.  Also see option -view.

       -view=bits
              Bitwise  value to specify which graphics to show each time some information is printed.  The least
              significant bits of bits indicate which  sub-panel  to  display.   Use  -view=0  to  suppress  all
              graphics  and  -view=-1  to  show  all graphics.  The default is to not display anything.  If some
              graphics are shown, the graphic window has to be closed  at  the  end  of  the  reconstruction  to
              effectively quit the program.

   Optimizer Settings
       -mem=number
              Specify the number of previous steps to memorize in VMLMB.

       -ftol=real
              Specify the function tolerance for the global convergence.

       -gtol=real
              Specify the gradient tolerance for the global convergence.

       -maxiter=number
              Specify the maximum number of iterations for all reconstructions.

       -maxeval=number
              Specify the maximum number of evaluations of the objective function for all reconstructions.

   Line Search Parameters
       -sftol=real
              Specify the function tolerance for the line search.

       -sgtol=real
              Specify the gradient tolerance for the line search.

       -sxtol=real
              Specify the step tolerance for the line search.

   Output File
       -overwrite
              Overwrite output file if it exists.

       -bitpix=number
              Specify  the  bits  per  pixel  for the output FITS file.  Default is -32, that is 32-bit floating
              point values.

       -save_initial
              Save initial image as a secondary HDU in the output file.

   Miscellaneous
       -help  Print out this help.

       -version
              Print out version number.

AUTHOR

       Éric Thiébaut <https://github.com/emmt/MiRA>

REFERENCES

       Thiébaut, É.: MiRA: an effective imaging algorithm for optical interferometry, in SPIE Proc. Astronomical
       Telescopes and Instrumentation 7013, 70131I-1-70131I-12 (2008) <http://dx.doi.org/10.1117/12.788822>

       Thiébaut,  É.  &  Giovannelli,  J.-F.:  Image  Reconstruction  in  Optical Interferometry, in IEEE Signal
       Processing Magazine 27, pp. 97-109 (2010) <http://dx.doi.org/10.1109/MSP.2009.934870>