A method for building a coherent radar cross-section (RCS) model database for real-time dynamic simulation of range-Doppler radars is disclosed. The database may be used with radar sensors that employ different waveforms. A pre-processing operation before the dynamic simulation performs fast Fourier Transforms (FFTs) to interpolate the target frequency responses from the database to match the frequency samplings of the radar used in the dynamic simulation. The method determines the frequency responses of the targets to a reference chirp in a coherent processing interval (CPI) and the radial velocities of the targets relative to the radar at the time of the reference chirp. The method extrapolates, using FFTs, the frequency responses of the targets to the reference chirp across the velocity dimension based on the relative radial velocities to determine the frequency responses of the targets to the other chirps across the CPI, reducing the computational burden for the simulation.