README for the GREAT3 metric evaluation truth tables
====================================================

The tarball great3_metric_evaluation_truth.tar will unpack to make the following
files:

    control-ground-constant.tar.gz
    control-ground-variable.tar.gz
    control-space-constant.tar.gz
    control-space-variable.tar.gz
    full-ground-constant.tar.gz
    full-ground-variable.tar.gz
    full-space-constant.tar.gz
    full-space-variable.tar.gz
    multiepoch-ground-constant.tar.gz
    multiepoch-ground-variable.tar.gz
    multiepoch-space-constant.tar.gz
    multiepoch-space-variable.tar.gz
    real_galaxy-ground-constant.tar.gz
    real_galaxy-ground-variable.tar.gz
    real_galaxy-space-constant.tar.gz
    real_galaxy-space-variable.tar.gz
    variable_psf-ground-constant.tar.gz
    variable_psf-ground-variable.tar.gz
    variable_psf-space-constant.tar.gz
    variable_psf-space-variable.tar.gz

Each of these tar.gz files will itself unpack into a GREAT3 branch data-like
folder structure.

For constant shear branches, the ASCII text files `shear_params-*` list the g1
and g2 shear applied to each subfield.  The text files `starshape-parameters-*`
contain information about the PSFs in the constant shear images, which allows
the metric evaluation code to rotate into the coordinate frame defined by the
PSF ellipticity for calculation of m & c bias parameters.

For variable shear branches, the binary FITS table files `galaxy_catalog-*.fits`
contain the following hopefully self-explanatory columns:

    ID, g1, g2, g1_intrinsic, g2_intrinsic

with an entry for every galaxy.  The g1_intrinsic and g2_intrinsic come from
either the obvious and unique values for single Sersic component models, or from
adaptive moments estimates of the intrinsic ellipticity in the two component
models of the COSMOS the galaxy images (described in the GREAT3 Handbook).  The
text files `subfield_offset-*` contain the information about the location of
each subfield within the larger field, which allows the variable shear metric
evalutation code to estimate the aperture mass dispersion for each field.