Method for ocean surface wind field retrieval from a common reflector dual-frequency SAR

In accordance with the ability to obtain further target characteristic information when detecting the same surface area with L/C common reflector dual-frequency SAR dual-band electromagnetic wave, a new ocean wind field retrieval method is proposed. Wind speed and direction are estimated simultaneously using a geophysical model function and a normalized radar cross sections of the L/C dual-band in accordance with a common reflector dual-frequency SAR geophysical model function, and the fuzzy direction of 180° is wiped off using auxiliary data. Verification results show that the wind field retrieval method can be used to retrieve a high-precision wind speed and direction without other background sources in accordance with the simulation and airborne synchronous flight test on a sea. The major error can be explained by the insufficient accuracy in calibrating the NRCS for wind speed and direction retrieval. The wind speed error increases with the value of speed, and the root mean square error of wind speed and direction between retrieval and survey ship observed are 0.93m/s and 19.39°, respectively. The method for ocean surface wind field retrieval from the common reflector dual-frequency SAR solves the inherent problems of a sea surface wind field inversion of the traditional single-band SAR and increases the retrieval accuracy of the sea surface wind speed and direction, thereby providing support for business application and load developing of an ocean wind field retrieval from space-borne SAR images. © 2019, Science Press. All right reserved.