FIELD: radar systems. SUBSTANCE: invention relates to radar systems. The method of retrospective determination of the trajectory of an object's movement is characterized by the fact that using a radar receiver of the radar system, radar data about detected objects in previous sounding cycles are collected and stored for a certain period of time, at the initial time t = t0 a standard radar track of the object is formed based on the collected radar data update the standard radar track over a period of time. Each retrospectively built track of the object is assigned a lattice diagram; to obtain the current estimate of the path, only the set of the most plausible paths of the object is used, the most probable path is the path obtained at the current step with the lowest total estimate. A device for retrospective determination of the trajectory of an object has an antenna system associated with a controlled microwave transceiver microcircuit containing a generator connected to any of the n-transmitting antennas, an amplifier, the signal input of which is connected to any of the m-receiving antennas, and the signal output is connected to the first input of the mixer, the second signal input of the mixer is connected to the signal generator. EFFECT: reduced processing time for tracks from various moving objects. 3 cl, 3 dwg.