Extraction method of ocean internal wave parameters of SAR image

Abstract

The invention provides an extraction method of ocean internal wave parameters of an SAR image. The method comprises steps of based on local low-rank prior, constructing a local low-rank optimization model for an image sheet including ocean internal waves; and by carrying out alternative optimized solving on the model, obtaining an optimal rotation angle shown in the description, a low-rank image sheet shown in the description and a high radiation resolution image sheet shown in the description, thereby extracting the wavelength omega of the ocean internal wave of the SAR image. According to the invention, through the constructed local low-rank optimization model, by fully use of the statistical feature of coherent spots of the SAP image and the local low-rank feature of the ocean internal wave, coherent spots of the SAR image can be well inhibited, target structure information protection and target scattering feature keeping are performed, target identification of the SAR image is effectively achieved, feature extraction can be still achieved in case of quite weak contrast ratio and damaged waveform of the ocean internal wave, and stable numerical solution can be performed on the model and is easy to achieve.

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 waves are a relatively common ocean phenomenon. The complexity of its 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-time, all-weather, and penetrating, and is widely used in ocean internal wave remote sensing observations. With the help of meteorological data and hydrological data, the calculation of ocean internal wave dynamic parameters can be realized by extracting the core parameters in SAR images. Affected by imaging conditions, the coherence speckle and background clutter in marine SAR images are relatively serious, and the image radiation resolution is low, resulting in the degradation of ocean...

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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