Reflector-Based SAR Systems with Digital Beamforming: Optimizing Performance by Variable Transmit Signal Bandwidth

Abstract:
In recent years the complexity of space borne SAR sensors has increased dramatically. This development is mainly driven by the need of a higher mapping capability of these systems with better performance in terms of swath width, resolution and sensitivity. To deal with these challenges innovative SAR concepts have been proposed, where a significant part of the radar signal processing is carried out onboard the spacecraft. This paper identifies further optimization potentials for reflector-based SAR systems with digital beamforming. Array-fed reflectors allow the simultaneous transmission of spatially separated waveforms. This inherent property can be exploited in order to reduce the amount of data to be downlinked to ground and decrease the energy consumption of the SAR instrument at the same time.