Feasibility of a Synthetic Aperture Radar with Rotating Antennas (ROSAR)

ROSAR (Rotor-SAR) is a synthetic aperture radar concept based on rotating antennas of a helicopter for pilot sight target detection and target localisation with high resolution. The ROSAR concept has potential benefits for civil and military helicopterborne imaging application, if the antennas are mounted at the tips of the rotor blades, for example (Fig. l). The concept has two main potential benefits, that are, the imaging field of view is 360° and there is no need for a forward velocity of the carrier platform. As opposed to SAR systems based on linear movement of the antenna, ROSAR imaging is based on synthetic apertures of a circular shape. Thus, the image formation process requires a polar format processing architecture. The ROSAR principle is also applicable for other radar mapping systems with rotating antennas, not only for helicopters.