Abstract
This report is a documentation of the research done on a small satellite Synthetic Aperture Radar (SAR) missions. The first two chapters give background and scope of the research. The third chapter is an introduction to the theory of SAR. The fourth chapter describes the feasibility study of a Synthetic Aperture Radar Mission for the UoSAT minisatellite platform. The mission requirements and the spacecraft are described. Based on the spacecraft constraints, several design options are presented. The proposed design is a medium resolution Synthetic Aperture Radar operating at a lower than nominal PRF and high duty cycle. The detrimental effect of the low PRF is mitigated by the low azimuth processing bandwidth required due to the low resolution. The high duty cycle allows for a low peak transmit power and thus for a distributed solid state transmitter without excessively increasing the weight and complexity of the antenna. The low PRF increases the available swath width, improving local coverage. One of the side effects of using a low PRF is that it changes the shape of the spectrum, making it more flat. This makes Doppler centroid estimation using the SAR data more difficult. The remainder of the research described in the fifth chapter focused on the feasibility of Doppler centroid estimation with a system running at low PRF. The investigation was done by simulating different types of data and estimation algorithms found in literature on synthetic aperture radar processing. The simulation results show that the Doppler centroid estimation was feasible even within the framework of the small satellite SAR despite the effects of the low PRF. The overall summary and conclusions are given in the sixth chapter.