Antenna aperture design scheme for the bistatic forward looking SAR application

Many image sensors such as the camera, the EO/IR (electro-optic infrared), the LADAR (laser detection and ranging) for unmanned vehicle systems have been investigated [1][2]. However, these sensors cannot provide terrain information through the vegetation, fog, dust and so on. They recognize them as a wall which cannot go through. But the unmanned vehicle can go through them. But, the rock, the stump or the puddle behind the vegetation canopy or fog are big obstacles for the unmanned vehicle. Therefore, the penetrating sensor is needed for the unmanned vehicle in some situations. The synthetic aperture radar (SAR) image sensor using the UWB (ultra-wideband) technique can be an appropriate solution for an unmanned vehicle in the field condition due to the penetrating characteristics of a microwave. However, lots of SAR image sensors provide side looking radar image which is perpendicular to the path of platform´s moving. The forward looking image is required for unmanned vehicle systems. In this paper, the approach to design the antenna aperture on forward looking SAR is presented.