As the motion of ballistic targets in midcourse is the complex motion of micro-motion and translation

the translational motion should be compensated to extract micro-Doppler information. The motion model for ballistic targets in midcourse is analyzed and constructed first

and then the rationality of regarding translational motion as a second order polynomial is illustrated. On this basis

a novel method based on two-dimensional spectral vector is proposed to estimate translation parameters. Exploiting the relationship between frequency spectrum and translation parameters

the energy distribution and center of gravity in frequency domain are quantized for zoomed echo signal. Thus the speed and acceleration can be compensated with a high precision. Simulation results show this method exhibits excellent estimation performance under group-target and strong noise environment.