A Method for Extracting Ocean Internal Wave Parameters from SAR Images

Abstract

The present invention provides a method for extracting oceanic internal wave parameters in SAR images. The method is based on local low-rank priors, and constructs a local low-rank optimization model for image slices containing oceanic internal waves, and solves the problem by alternately optimizing the model. , to obtain the optimal rotation angle low-rank image slice and high radiation resolution image slice to extract the SAR image ocean internal wave wavelength ω. The local low-rank optimization model constructed by the present invention makes full use of the statistical characteristics of SAR image coherence spots and the local low-rank characteristics of ocean internal waves, which can well suppress SAR image coherence spots, protect target structure information and target scattering characteristics Maintaining and effectively realizing SAR image target recognition, feature extraction can still be achieved in the case of weak ocean internal wave contrast and waveform damage, and the model can be robustly solved numerically, which is easy to implement.

Description

Technical field [0001] The invention relates to an image feature extraction method, in particular to a SAR image ocean internal wave parameter extraction method. Background technique [0002] Ocean internal wave is a relatively common ocean phenomenon. The complexity of its occurrence mechanism and its randomness in time and space make internal wave detection a frontier research topic in the ocean field. As a high-resolution microwave imaging radar, Synthetic Aperture Radar has the advantages of all-weather, all-weather and penetrability, and is widely used in ocean internal wave remote sensing observation. With the help of meteorological data and hydrological data, the calculation of dynamic parameters of ocean internal waves can be realized by extracting core parameters from SAR images. Affected by the imaging conditions, the coherent speckles and background clutter of the marine SAR image are more serious, and the image radiation resolution is low, which causes the degradatio...

AI Technical Summary

Problems solved by technology

At present, the extraction method of ocean internal wave parameters in SAR images faces the following problems: (1) The internal wave hydrodynamic model in the internal wave parameter extraction method generally adopts the classic KdV equation, which is not applicable under any conditions; (2) Simultaneously In some methods, the amplitude extraction depends on the accuracy of the extracted wavelength, but in practice, due to the influence of imaging conditions, in many cases, the band characteristics of the internal wave in the SAR image are not obvious, the noise interference is serious, and even the bright and dark bands are missing. (3) Measured data is the best way to verify the accuracy of extraction, but many SAR images do not have synchronous field observation data. Due to the lack of field hydrological synchronous measurement data, existing methods must rely on historical hydrological data. The accuracy and spatio-temporal consistency of historical hydrological data are not ideal

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