Spaceborne Sea Ice Edge Detection Using TechDemoSat-1 GNSS-R Signals

In order to detect the sea ice edge (SIE) from Global Navigation Satellite System Reflectometry (GNSS-R), a model that may be employed in space is being developed in this research. The method is used delay-Doppler maps (DDM) of GNSS-R with K-means cluster algorithm. Here, the sea ice or sea water reflected power of delay maps (DM) is derived from the DDM, then a K-means cluster method is adopted to obtain the clustering center of sea ice and sea water. Combined with the specular reflection point position, it enables us to distinguish sea ice edge through studying the values of K-means cluster observable. Comparing with the global sea ice distribution map, the specular reflection point corresponding to the threshold value of K-means cluster basically coincides with the sea ice boundary position of the sea ice distribution map. The DDM data was obtained from the UK TechDemoSat-1 (UK TDS-1) experiment. According to the training observable of K-means cluster, it can be judged as sea ice or sea water by comparing the thresholds, respectively. By comparing K-means observable based on detection results with a map of the distribution of sea ice around the world, this method's viability is demonstrated with an accuracy of up to 99%.