Medium PRF Waveforms: an optimal solution for various applications in surface based radar

In this paper the Pulse Repetition Frequency (PRF)-induced targetfold back dilemma in the range-velocity domain of the Pulsed Doppler (PD)-radar is addressed for `surface based' applications, i.e. naval or ground based radar. The terms low-, medium- and high-PRF radar are related to the Radar carrier Frequency (RF)-dependent clutter pollution ratio in the unambiguous fundamental velocity or Doppler domain. It is recognised that the conventional low-PRF MTI-radar provides aircraft detection over single-type surface clutter, such as land or sea only. However, to detect bird-sized or stealthy targets in a vast number of environments (e.g. littoral) high stability and dynamic range PD-radar is required. In this paper a design strategy is described for PRF regimes which allow for stealth target visibility in noise and clutter backgrounds in large range-velocity domains. In most cases, low- and high-PRF regimes can be discarded due to unresolvable clutter pollution ratios in the velocity and range domain respectively, resulting in target invisibility and generation of formidable, -system-paralysing-, false alarm rates. Although problems can arise for high pollution ratios in the range-velocity domain (e.g. for high RF's or antenna positions), medium-PRF regimes have the potency to `match' with stressing requirements as for surface based antennas in challenging threat scenarios of today and in the future.