Missiles with only an infrared (IR) seeker can only be aware of the angular kinematics of the engagement - line of sight (LOS) angle and LOS angular velocity. However, in some occasions, missiles with IR seekers can be fed with low frequency range information, which is mostly provided by search radars. Nevertheless, it could be shown that, such scarcity in range information is not sufficient to solve the target-missile kinematics analytically. Still, certain numerical solutions can be applied in such situations. In this paper, a simple algorithm to estimate the velocity vector of a target using the range information provided by a search radar is proposed.