  One of the most challenging tasks in lattice calculations of baryon form
factors is the analysis and control of excited-state contaminations. Taking the
isovector axial form factors of the nucleon as an example, both a dispersive
representation and a calculation in chiral effective field theory show that the
excited-state contributions become dominant at fixed source-sink separation
when the axial current is spatially distant from the nucleon source location.
We address this effect with a new method in which the axial current is
localized by a Gaussian wave-packet and apply it on a CLS ensemble with
$N_f=2+1$ flavors of O($a$) improved Wilson fermions with a pion mass of
$m_\pi=200\,$MeV.
