  We characterize the disorder induced localization in momentum space for
ultracold atoms in one-dimensional incommensurate lattices, according to the
dual Aubry-Andr\'e model. For low disorder the system is localized in momentum
space, and the momentum distribution exhibits time-periodic oscillations of the
relative intensity of its components. The behavior of these oscillations is
explained by means of a simple three-mode approximation. We predict their
frequency and visibility by using typical parameters of feasible experiments.
Above the transition the system diffuses in momentum space, and the
oscillations vanish when averaged over different realizations, offering a clear
signature of the transition.
