A Frequency Diversity Algorithm for Extending the Radar Doppler Velocity Nyquist Interval

Abstract

Compact millimeter wavelength radars have been widely used for applications such as remote sensing of clouds, guidance avionics and recently, automotive navigation. However, the short wavelength of these radars limit their maximum unambiguous Doppler velocity. A common solution to this problemis to subsequently unfold the Doppler velocity estimate with the staggered pulse repetition time (PRT) algorithm, which requires two different PRTs to be employed in sequence. This work investigates a novel and potentially more rapid method to extend the Doppler velocity Nyquist interval. The investigated algorithm uses a pair of frequency diverse pulses separated by a short time lag for Doppler velocity estimation while the unambiguous range still corresponds to the pulse repetition time employed.