Second-generation maximizes COSMO-SkyMed system capabilities
COSMO-SkyMed Second Generation (CSG) is the first synthetic aperture radar (SAR) satellite system in the world able to acquire two images simultaneously. Launched on December 18, 2019, the satellite is now completing in-orbit tests to ensure joint operability with the four COSMO-SkyMed First Generation satellites, thus increasing the system’s overall capabilities.
Keeping a radar eye on Earth
Earth observation from space is crucial, since it helps define and implement responsible environmental policies at local, national, regional and international levels. Thales Alenia Space is a center of excellence in spaceborne environmental monitoring. Since the first launch in 2007, the COSMO-SkyMed dual (civil/defense) radar observation system built by Thales Alenia Space on behalf of the Italian space agency ASI and the Italian Ministry of Defense, has continuously monitored the Earth’s surface. It meets government requirements, while helping us deal with natural disasters, optimize the use of our natural resources, protect populations at risk and much more. Most recently, COSMO-SkyMed took impressive shots of the rebuilt bridge in Genoa, Italy, two years after it collapsed in August 2018.
The SAR sensor’s versatility and electronic agility enabled the development of a new operating mode, DI2S-MS, or “DIscrete Stepped Strip Multi-Swath”, which allows the simultaneous acquisition of two targets on the earth’s surface that are hundreds of kilometers apart. Overcoming the constraints of the conventional SAR spotlight mode, the DI2S-MS mode allows capturing two spotlight images simultaneously, using dual polarization. The DI2S-MS project began in 2014, inspired by an intuition of Diego Calabrese, Thales Alenia Space Italy technical manager for the development of CSG. He realized that he could use the agility offered by the electronics and SAR antenna on COSMO-SkyMed Second Generation, which he had designed and patented as a “DIscrete Stepped Strip” (DI2S). Along with innovative solutions for the Earth segment, this made it possible to overcome some of the traditional restrictions of SAR devices and improve their quality and serviceability, for example by addressing user access requests for geographically separate areas.
The figure below shows two very-high-resolution (sub-metric) SAR spotlight images taken simultaneously in DI2S-MS mode by the first COSMO-SkyMed Second Generation satellite on April 25, 2020 in the Rome and Altamura regions, processed by Telespazio at the Matera Space Center.
Image credit: On February 5, 2020, the first second-generation COSMO-SkyMed satellite acquired this image of the Hofsjökull glacier in Iceland. A radar image provides a better perception than optical imagery of the complexity of the glacier and the morphology of the surrounding snow-covered area.