SCATSAT-1 Scatterometer:An Improved Successor of OSCAT

SCATSAT-1 is the Indian Space Research Organisation’s (ISRO’s) newest Ku-band scatterometer which was launched on 26 September 2016 from ISRO’s space-port Sriharikota on-board the PSLV C35 mission. It is an advanced follow-on of OSCAT, ISRO’s first Scatterometer in space on-board the Oceansat-2 satellite, which ceased to operate in April 2014. OSCAT had been a globally acclaimed sensor during its lifetime. The data from SCATSAT-1 exhibit superior quality, and will not only serve the operational wind and weather prediction community in the years to come, but also hold the promise of securing a place in the long-term climate data records. SCATSAT-1 is a standalone scatterometer mission atop the Indian Mini Satellite (IMS-2) bus. The scatterometer payload is a two-beam, dual-polarized, conically scanning, pencil beam, real-aperture radar which measures near-surface wind vectors over ocean exploiting Bragg scattering resonance at Ku-band. It has been developed in ISRO’s Space Applications Centre, Ahmedabad in less than two and half years to replace OSCAT. Although it inherits the instrument specifications from OSCAT, several enhancements have been made in its hardware as well as in the payload characterization from the purview of miniaturization and performance improvement over OSCAT. This article highlights the hardware improvements, the payload characterization methods devised, and the performance enhancements of SCATSAT-1 over OSCAT. The in-orbit performance of SCATSAT-1 is also discussed.