  We study localised exact coherent structures in plane Poiseuille flow that
are relative periodic orbits. They are obtained from extended states in
smaller, periodically continued domains, by increasing the length to obtain
streamwise localization and then by increasing the width to achieve spanwise
localisation. The states maintain the travelling wave structure of the extended
states, which is then modulated by a localised envelope on larger scales. In
streamwise direction, the envelope shows exponential localization, with
different exponents on the upstream and downstream side. The upstream exponent
increases linearly with Reynolds number Re, but the downstream exponent is
essentially independent of Re. In the spanwise direction the decay is
compatible with a power-law localisation. As the width increases the localised
state undergoes further bifurcations which add additional unstable directions,
so that the edge state the relative attractor on the boundary between the
laminar and turbulent motions, in the system becomes chaotic.
