UK: Surrey Satellite Technology Ltd. (SSTL), small satellite manufacturer, announced completion of the development phase of its new low-cost Synthetic Aperture Radar (SAR) satellite system. Called NovaSAR-S, the system offers coverage of any spot on Earth in all conditions – seeing through cloud cover across both day and night.
The 400-kg NovaSAR-S design combines SSTL’s flight-proven SSTL-300 platform with an innovative S-band SAR payload, developed in collaboration with Astrium Ltd., who will be responsible for supplying the payloads. The challenge has been accommodating the power and processing requirements within a small, low-cost satellite platform. NovaSAR-S’s 3m x 1m phased array antenna was developed by space-borne SAR specialists at Astrium Ltd, and has now been successfully trialled using an airborne demonstrator. The SSTL-300 platform hosting the payload is an adaption of SSTL’s very-high-resolution imaging NigeriaSat-2 mission, which was launched in August.
“Based on highly efficient S-band solid state amplifier technology, NovaSAR-S has been designed to provide detailed imaging performance for a variety of orbits,” said Luis Gomes of SSTL. “It offers space-based radar capability to customers who might not have considered it possible – all for the equivalent cost of a traditional low cost optical Earth observation mission.”
NovaSAR-S acquires medium resolution radar imagery of 6-30 m ground sample distance, depending on the viewing mode being employed. Its four viewing modes are optimised for a wide range of applications, including flood monitoring, agricultural crop assessment, forest monitoring, land cover classification, disaster management and maritime applications – notably ship tracking and oil spill detection.
Radar images reveal surface textures instead of reflected light. A radar satellite illuminates its target with a microwave beam then records the signal bouncing back. In addition, the satellite takes advantage of its rapid motion relative to Earth’s surface to build up an image with sharpened resolution equivalent to that of a much larger ‘synthetic aperture’ antenna.
Intended for equatorial or polar low-Earth orbits, NovaSAR-S offers high data throughput of at least one million square km per day, observing in a variety of polarisation combinations to add ‘colour’ and detail to acquisitions.
The system is designed to function either independently, or as part of a constellation. A trio of NovaSAR-S satellites could image any point on the globe every day, regardless of local weather or time of day.