We study the properties of transmissivity of a beam of atoms traversing an optical lattice loaded with ultracold atoms. The transmission properties as a function of the energy of the incident particles are dependent on the quantum phase of the atoms in the lattice. In fact, in contrast to an insulator regime, the absence of an energetic gap in the spectrum of the superfluid phase enables the atoms in the optical lattice to adapt to the presence of the beam. This induces a backaction process that has a strong impact on the transmittivity of the atoms. Based on the corresponding strong dependency we propose the implementation of a speed sensor with an estimated sensitivity of 108-109(m/s)/Hz. We point out that the velocity sensitivity improves when the interaction term in the optical lattice increases. Applications of the presented scheme are discussed.
