Abstract
UrtheCast and KACST have jointly been developing an entirely new generation of spaceborne SAR instrument, called SAR-XL, that is modular, low cost and provides multi-aperture, multi-polarization and simultaneous dual-frequency with a fully digitally beamformed phased array antenna. The core technology elements include a high efficiency shared aperture X and L-band phased array antenna, the Digital RF Unit (DRFU), Transmit / Receive Modules (TRMs), Intermediate Frequency Conversion Units (IFCUs), and the SAR Processor and Controller Unit (SPCU). Development of these core technology elements is now well advanced and is culminating in the test of a flight representative Engineering Model (EM) of the SAR-XL payload comprising of two full SAR panels and the Antenna Interface Controller board from the SPCU with the firmware developed with full functionality. In addition, significant work has been undertaken on the development and demonstration of the onboard SAR processing for both X-band and L-band that enables fully exploiting the unique benefits of a dual-frequency, digitally beamformed SAR Instrument. The paper describes the development of the core SAR-XL technology elements and presents test results demonstrating the functionality and performance. The technology is highly modular and can be configured into a large range of antenna configurations. The payload level performance is provided for two antenna configurations, a 6.4 m x 1.8 m antenna used as the basis for the development program and a high-performance configuration with a 10.7 m x 2 m antenna. The paper also describes the unique applications that are enabled by the dual band, multi-polarization and fully digital nature of this instrument.