Disclosed are techniques for liveliness detection. In an aspect, a 
radar sensor of an electronic device transmits a 
radar frame comprising a plurality of bursts, each burst comprising a plurality of 
radar pulses, and receives a plurality of reflected radar pulses. The electronic device generates a radar image representing 
azimuth, elevation, range, and 
slow time measurements for the radar 
frame based on the plurality of reflected pulses, applies a Doppler FFT to the radar image to convert the radar image to represent 
azimuth, elevation, range, and velocity measurements for the radar frame, identifies at least one area of motion in the radar 
image based on velocity bins of the radar image, and detects a target dynamic 
object based on a CFAR detection applied over the range and 
azimuth measurements and a SNR threshold of the received plurality of reflected pulses associated with the at least one area of motion.