  We study gluon radiation in top quark production above threshold at high
energy $e^+e^-$ colliders. We allow for the top quarks to be off-shell,
considering radiation in both the top production and decay processes
simultaneously. Our calculation includes all top width effects, spin
correlations, and $b$ quark mass effects. We study the effects of gluon
radiation on top mass reconstuction and examine the interference between
production- and decay-stage radiation, which can be sensitive to the value of
the top quark decay width.
