Another research direction of the group is investigating the light dragging effect in an electromagnetically induced transparent medium. We take advantage of the large dispersive response of the medium to develop a velocity sensor. Such a device has a unique property that it is a complete motional sensor where both velocity and acceleration can be measured simultaneously while the atom interferometric sensor can only measure the differentiation of the velocity. Moreover, this technique measures the collective response of an ensemble of atoms directly as opposed to single-atom measurements of conventional atomic velocity sensors. We have demonstrated a preliminary prototype of this scheme and used it to directly sense the center-of-mass motion of an atomic ensemble. Our result shows a velocity sensitivity two orders of magnitude better than the Doppler width of the atomic sample.