Abstract: A ship-based over-the-horizon (OTH) radar system provides mobile, persistent, wide-area air and ship surveillance across large ocean expanses and in anti-access/area denial (A2AD) environments. A transmit ship may include a log-periodic antenna (LPA) array adapted for use on a ship and a receive ship may include a plurality of monopole or dipole whip antennas. The transmit/receive antenna is fronted by a ground screen, which can be sized taking into account the sea as a naturally reflective surface. The transmit/receive ship can include advanced software to compensate for ship movement and synthetic aperture radar (SAR) techniques can be employed to includes the effective size of the radar receiver aperture. A modular design, using standard commercial container ships and shipping containers, allows for rapid deployment/stowage of radar equipment. Related methods are also described.