Circularly Polarized Synthetic Aperture Radar Onboard Unmanned Aerial Vehicle (CP-SAR UAV)

Abstract

Synthetic aperture radar (SAR) is well known as a multipurpose sensor that can be operated in all-weather and day–night time. Recently, many missions of SAR sensors are operated in linear polarization with high power, sensitive to Faraday rotation effect, etc. This chapter discusses the theoretical design of novel circularly polarized synthetic aperture radar (CP-SAR) onboard unmanned aerial vehicle (UAV) to retrieve the physical information of Earth’s surface. The CP-SAR system is considered as small, light in weight, and low power consumption system. The CP-SAR sensor is employing the elliptical wave propagation and scattering phenomenon by radiating and receiving the elliptically polarized wave, including the special polarization as circular and linear polarizations. Base on the size of CP-SAR and other sensor payload, we developed UAV called Josaphat Laboratory Experimental Unmanned Aerial Vehicle (JX-1) with wing span 6 m, platform length 4.75 m, and total weight 146 kg including sensor weight 25 kg. The first flight test of JX-1 was successfully held at Fujikawa Airfield, Japan, on 7 June 2012.