Ocean wind-field retrieval method of double-frequency coplanar synthetic aperture radar (SAR)

Abstract

The invention discloses an ocean wind-field retrieval method of a double-frequency coplanar synthetic aperture radar (SAR), relates to the technical field of remote sensing, and aims at developing a new ocean wind-field retrieval method according to the ocean detection characteristics of the double-frequency coplanar SAR. The method comprises the steps of performing radiometric calibration for an SAR image to obtain the calibrated SAR image; analyzing calculating backscattering coefficients through L-waveband and C-waveband geophysical model functions; then performing simultaneous restructuring for the L-waveband and C-waveband geophysical model functions to obtain the minimum cost functions; directly solving to obtain the ocean wind speed and wind direction; removing fuzzy wind direction. With the adoption of the method, the problem that the SAR ocean wind-field retrieval method depends on the background field wind direction data and wind stripes can be effectively solved, high-precision ocean wind speed and wind direction can be inverted directly through the back scattering of the radar, and therefore, the support is provided to the service application of the SAR ocean wind-filed detection.

Description

technical field [0001] The invention belongs to the technical field of remote sensing, in particular to a double-frequency coplanar synthetic aperture radar sea surface wind field inversion method. Background technique [0002] Synthetic aperture radar (SAR) is an active microwave imaging radar with the characteristics of all-weather, all-time, and high spatial resolution. Sea wind field. At present, to invert the sea surface wind field using SAR detection data, it is usually necessary to obtain the sea surface wind direction first, and then use the known relative wind direction, calibrated backscatter coefficient and incident angle as geophysical model functions (GMF, Geophysical Model Function) of different bands The input of the sea surface wind speed is obtained through iterative calculation. Usually, the numerical forecast value, the sea surface wind direction of the scatterometer, and the wind direction of the SAR image are used as the relative wind direction input o...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a dual-frequency coplanar synthetic aperture radar sea surface wind field inversion method, thereby effectively solving the problem that the SAR sea surface wind field inversion relies on background field wind direction data and wind stripes, and can directly backscatter from the radar The coefficient itself is highly accurate in inversion of sea surface wind speed and wind direction. This method is not affected by the limitation of swath width and the accuracy of channel crosstalk calibration and cross-polarization radiation calibration. business support

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