Track-Based Cyclone Maximum Wind Retrievals Using the Cyclone Global Navigation Satellite System (CYGNSS) Mission Full DDMs

Cyclone maximum wind retrievals are demonstrated using tracks of full delay-Doppler map (DDM) measurements of the Cyclone Global Navigation Satellite System (CYGNSS) constellation. The method is based on the production of a library of simulated DDMs for a synthetic storm model, as the parameters of the synthetic storm are varied. A matched filter approach between normalized simulated and measured DDMs is then applied to retrieve storm parameters. Because the method uses normalized DDMs in the retrieval, it is insensitive to the absolute power calibration of the DDM and instead relies on the DDM shape. Results from the method are shown for CYGNSS full DDM overpasses of Hurricane Irma as a case study. The maximum wind speed estimates obtained were associated with a retrieval root-mean-square error (RMSE) of 6.89 m/s and an unbiased RMSE 5.20 m/s with a mean difference of 4.52 m/s compared to reported National Hurricane Center Best Track forecasts.