Sea ice detection using GNSS-R delay-Doppler maps from UK TechDemoSat-1

In this paper, an approach based on Global Navigation Satellite System-Reflectometry (GNSS-R) is proposed for distinguishing sea ice and water from each other. The Delay-Doppler Map (DDM) of a GNSS signal reflected from sea ice and water show different spreading characteristics. The difference between two adjacent normalized DDMs is a differential DDM observable which provides information about the difference of two DDMs. Through studying whether the pixel number is above or below a predefined threshold, it is possible to determine the type of the reflected surface. The feasibility of the proposed differential DDM based method is validated using the ground-truth sea ice extent map provided by the National Snow and Ice Data Center, USA. The results demonstrate that the probability of detection can be up to 99.88%.