Triggering Freeze/Thaw Surface State Monitoring from High Inclination Orbit GNSS-R Missions: A CYGNSS-Based Study.

NASA's Cyclone Global Navigation Satellite System (CYGNSS) mission has been in orbit for more than 5 years. Following the Earth Science Division 2020 Senior Review, NASA announced last year it is extending the CYGNSS mission through at least 30th September 2023. The extended CYGNSS mission phase will focus on both ocean and land surface scientific investigations. One new recent application of CYGNSS is Freeze/Thaw (F/T) surface state detection and imaging [1]. The main objective of this presentation is the application of the retrieval algorithm developed in [1] over different high-interest target areas within the CYGNSS coverage to show the capability to provide long-term trending of F/T behaviour.