Circular polarization implementation on synthetic aperture radar

Synthetic aperture radar (SAR) is an active sensor using microwave to acquire the images of target in interest. To be operated, an SAR platform usually loaded on moving platform such as aerial vehicle or satellite then transmits and receives microwave signal for its own illumination sources. Space-borne SAR that is operated on space orbit uses ionosphere and air as a propagation medium. When linearly polarized microwave which conventional SAR system uses traverses thorough ionosphere, the reference plane of polarization rotates eventually causes polarization mismatch. To reduce the polarization mismatch, this paper proposes circular polarization on SAR sensor.