Recent Advances in Retrieval of Ocean Surface Wind Fields from GNSS-R delay-Doppler Maps

摘要

An Extended Kalman Filter (EKF) algorithm for the retrieval of surface wind field from satellite Global Navigation Satellite System-Reflectometry (GNSS-R) measurements is presented. EKF wind retrievals show improved accuracy when compared with a Principal Components Analysis (PCA), the best single-parameter observable defined for the Cyclone Global Navigation Satellite System (CYGNSS) mission. Furthermore, the EKF is capable of retrieving a wind field over the ocean swath defined by the full extent of the Delay-Doppler Map (DDM). PCA, in contrast utilizes only observations with the 25 km × 25 km resolution cell centered on the specular point. This algorithm is applied to simulated DDMs obtained from the CYGNSS end-to-end simulator (E2ES) using wind data from a "nature run" tropical storm simulation and actual measurements from Hurricane Danielle.